From 7d3557a3fd4385ce91cdd168e8a3852f963d0a6b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Bombeck?= <marc@bombeck.io>
Date: Fri, 12 Jun 2026 17:42:31 +0200
Subject: [PATCH] fix(medications): every taken dose moves the stock, in units
 that match the product
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Stock only decremented on the web card's take button — the status
toggle, the phone sync, the Telegram buttons and the token API all
recorded the dose and left the inventory untouched, which is why a
fresh pack kept reading full. Consumption now stamps the intake row
itself: every path that turns a row taken consumes through one module
— open container first, then earliest expiry with auto-open, spilling
into the next pack and flooring at zero — and every path that takes it
back (undo, delete, a take turned skip, a converged duplicate)
refunds exactly what the stamp recorded. Replays and pending sync
echoes can never double-charge, and the nightly convergence pass
refunds the rows it tombstones. A medication can declare units per
dose, so two 2 mg tablets book as one 4 mg dose and stock reads in
doses with the unit count alongside; containers carry a named type
including tablet packs, hold up to a thousand units for inhalers, and
the GLP-1 card reads the same stock as the inventory tab instead of a
separate ledger. The inventory endpoints join the documented API.
---
 docs/api/openapi.yaml                         | 443 +++++++++++-
 messages/de.json                              |  39 +-
 messages/en.json                              |  39 +-
 messages/es.json                              |  39 +-
 messages/fr.json                              |  39 +-
 messages/it.json                              |  39 +-
 messages/pl.json                              |  39 +-
 .../0149_v11610_inventory_units/migration.sql |  36 +
 prisma/schema.prisma                          |  47 +-
 .../inventory-write-isolation.test.ts         |  79 +++
 .../ingest/medication/__tests__/route.test.ts |  49 ++
 src/app/api/ingest/medication/route.ts        |  12 +
 src/app/api/insights/glp1-timeline/route.ts   |   9 +
 .../[id]/glp1/__tests__/route.test.ts         |  75 +-
 src/app/api/medications/[id]/glp1/route.ts    |  35 +-
 .../intake/[eventId]/__tests__/route.test.ts  | 174 +++++
 .../[id]/intake/[eventId]/route.ts            |  50 ++
 .../[id]/intake/__tests__/route.test.ts       |  24 +-
 .../bulk-delete/__tests__/route.test.ts       |  41 ++
 .../[id]/intake/bulk-delete/route.ts          |  16 +-
 src/app/api/medications/[id]/intake/route.ts  |  65 +-
 .../[itemId]/__tests__/route.test.ts          |  18 +-
 .../[id]/inventory/[itemId]/route.ts          |  21 +-
 .../[id]/inventory/__tests__/route.test.ts    |  17 +-
 .../api/medications/[id]/inventory/route.ts   |  11 +-
 src/app/api/medications/[id]/route.ts         |   4 +
 .../intake/__tests__/route.test.ts            | 154 ++++
 .../intake/bulk/__tests__/route.test.ts       | 185 +++++
 src/app/api/medications/intake/bulk/route.ts  |  54 +-
 src/app/api/medications/intake/route.ts       |  41 ++
 src/app/api/medications/route.ts              |   3 +
 .../telegram/webhook/__tests__/route.test.ts  |  21 +
 src/app/api/telegram/webhook/route.ts         |  39 +-
 .../__tests__/add-inventory-dialog.test.tsx   | 173 +++++
 .../__tests__/supply-runway.test.ts           |  24 +
 .../detail/MedicationDetailTabs.tsx           |  32 +-
 .../sections/inventory-section.tsx            | 229 +++++-
 .../wizard/__tests__/wizard-payload.test.ts   |  44 ++
 .../medications/wizard/steps/Step3Dose.tsx    |  32 +-
 .../medications/wizard/wizard-payload.ts      |  21 +
 .../ai/coach/__tests__/glp1-snapshot.test.ts  |  24 +-
 src/lib/ai/coach/glp1-snapshot.ts             |  31 +-
 .../intake-slot-dedup-inventory.test.ts       | 171 +++++
 src/lib/medications/intake-slot-dedup.ts      |  23 +
 .../inventory/__tests__/consumption.test.ts   | 655 ++++++++++++++++++
 .../inventory/__tests__/service.test.ts       | 112 +--
 .../inventory/__tests__/state-machine.test.ts |  84 +--
 src/lib/medications/inventory/consumption.ts  | 377 ++++++++++
 src/lib/medications/inventory/service.ts      | 114 +--
 .../medications/inventory/state-machine.ts    | 131 +---
 src/lib/openapi/routes/medications.ts         | 193 ++++++
 .../__tests__/medication-inventory.test.ts    | 166 +++++
 src/lib/validations/medication.ts             | 166 +++--
 53 files changed, 4118 insertions(+), 641 deletions(-)
 create mode 100644 prisma/migrations/0149_v11610_inventory_units/migration.sql
 create mode 100644 src/__tests__/inventory-write-isolation.test.ts
 create mode 100644 src/components/medications/__tests__/add-inventory-dialog.test.tsx
 create mode 100644 src/lib/medications/__tests__/intake-slot-dedup-inventory.test.ts
 create mode 100644 src/lib/medications/inventory/__tests__/consumption.test.ts
 create mode 100644 src/lib/medications/inventory/consumption.ts
 create mode 100644 src/lib/validations/__tests__/medication-inventory.test.ts

diff --git a/docs/api/openapi.yaml b/docs/api/openapi.yaml
index 541c54915..c01249a6a 100644
--- a/docs/api/openapi.yaml
+++ b/docs/api/openapi.yaml
@@ -2289,6 +2289,145 @@ paths:
                 $ref: "#/components/schemas/ErrorEnvelope"
         "422": *a3
         "429": *a4
+  /api/medications/{id}/inventory:
+    get:
+      tags:
+        - Medications
+      summary: List a medication's supply containers
+      description: Returns every inventory item (all states) for the medication, ordered by state, then `expiresAt`, then
+        `createdAt`. Items count UNITS; divide by the medication's `unitsPerDose` for dose-level figures.
+      parameters:
+        - in: path
+          name: id
+          schema:
+            type: string
+          required: true
+      responses:
+        "200":
+          description: Inventory item list.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ListMedicationInventoryResponse"
+        "401": *a1
+        "404":
+          description: Medication not found (or owned by another user).
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorEnvelope"
+        "422": *a3
+        "429": *a4
+    post:
+      tags:
+        - Medications
+      summary: Register a new supply container
+      description: Creates an ACTIVE inventory item with `unitsRemaining = unitsTotal`. The request's `dosesTotal` field
+        carries UNITS (1–1000). Rate-limited 30/min/user. Audits as `medication.inventory.create`.
+      parameters:
+        - in: path
+          name: id
+          schema:
+            type: string
+          required: true
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/CreateMedicationInventoryItemRequest"
+      responses:
+        "201":
+          description: Created inventory item.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/CreateMedicationInventoryItemResponse"
+        "401": *a1
+        "404":
+          description: Medication not found (or owned by another user).
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorEnvelope"
+        "422": *a3
+        "429": *a4
+  /api/medications/{id}/inventory/{itemId}:
+    patch:
+      tags:
+        - Medications
+      summary: Mutate a supply container
+      description: "Per-item operations: manual first-use (`markAsFirstUseAt`), used-up override (`markAsUsedUp`),
+        printed-expiry correction, absolute remaining-unit correction (`dosesRemaining`, clamped to the item's
+        capacity), notes. The canonical state machine re-derives the state after every mutation. Audits as
+        `medication.inventory.update`."
+      parameters:
+        - in: path
+          name: id
+          schema:
+            type: string
+          required: true
+        - in: path
+          name: itemId
+          schema:
+            type: string
+          required: true
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/UpdateMedicationInventoryItemRequest"
+      responses:
+        "200":
+          description: Updated inventory item.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/UpdateMedicationInventoryItemResponse"
+        "401": *a1
+        "404":
+          description: Inventory item not found (or owned by another user / medication).
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorEnvelope"
+        "422": *a3
+        "429": *a4
+    delete:
+      tags:
+        - Medications
+      summary: Delete a supply container
+      description: Hard-deletes the inventory item. The audit log captures the before-state (`medication.inventory.delete`) so
+        a row can be reconstructed if needed. Consumption stamps on intake events that reference the item stay in place;
+        a later restore skips the missing container.
+      parameters:
+        - in: path
+          name: id
+          schema:
+            type: string
+          required: true
+        - in: path
+          name: itemId
+          schema:
+            type: string
+          required: true
+      responses:
+        "200":
+          description: Deletion succeeded.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/DeleteMedicationInventoryItemResponse"
+        "401": *a1
+        "404":
+          description: Inventory item not found (or owned by another user / medication).
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ErrorEnvelope"
+        "422": *a3
+        "429": *a4
   /api/medications/extract:
     post:
       tags:
@@ -4532,6 +4671,12 @@ components:
         dosesPerUnit:
           type: integer
           minimum: 1
+          maximum: 1000
+        unitsPerDose:
+          description: Inventory units consumed per dose (e.g. 2 tablets of 2 mg for a 4 mg dose). Default 1. The intake
+            consumption hook decrements this many units per taken dose; dose-derived readouts divide unit counts by it.
+          type: integer
+          minimum: 1
           maximum: 100
         deliveryForm:
           type: string
@@ -4779,8 +4924,14 @@ components:
           anyOf:
             - type: integer
               minimum: 1
-              maximum: 100
+              maximum: 1000
             - type: "null"
+        unitsPerDose:
+          description: Inventory units consumed per dose (e.g. 2 tablets of 2 mg for a 4 mg dose). The intake consumption hook
+            decrements this many units per taken dose; already-stamped intake events keep their recorded consumption.
+          type: integer
+          minimum: 1
+          maximum: 100
         deliveryForm:
           type: string
           enum:
@@ -4940,6 +5091,78 @@ components:
         the per-day compliance rollup, and — for one-shot medications — flip `active` to false. The optional
         `injectionSite` is persisted only for an INJECTION medication with site-tracking enabled and is validated
         against the medication's effective allowed set (422 on a disallowed value).
+    CreateMedicationInventoryItemRequest:
+      type: object
+      properties:
+        dosesTotal:
+          type: integer
+          minimum: 1
+          maximum: 1000
+          description: Units the container ships with (tablets / ampoules / puffs; 1–1000). Stored as `unitsTotal`; dose-derived
+            readouts divide by the medication's `unitsPerDose`.
+        containerType:
+          description: Kind of physical container (PEN / AMPOULE / BLISTER / INHALER / BOTTLE / OTHER). Display-level only;
+            defaults to OTHER.
+          type: string
+          enum:
+            - PEN
+            - AMPOULE
+            - BLISTER
+            - INHALER
+            - BOTTLE
+            - OTHER
+        printedExpiry:
+          anyOf:
+            - type: string
+              format: date-time
+              pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+            - type: "null"
+        purchasedAt:
+          anyOf:
+            - type: string
+              format: date-time
+              pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+            - type: "null"
+        notes:
+          anyOf:
+            - type: string
+              maxLength: 200
+            - type: "null"
+      required:
+        - dosesTotal
+      description: Register a new supply container (pen / blister pack / bottle). `dosesTotal` counts UNITS (1–1000); the item
+        starts ACTIVE with `unitsRemaining = unitsTotal` and the intake consumption hook decrements it per taken dose.
+    UpdateMedicationInventoryItemRequest:
+      type: object
+      properties:
+        markAsFirstUseAt:
+          description: Manually start the 30-day in-use clock (the user opened the container without logging an intake). ACTIVE
+            flips to IN_USE; a backdated instant whose window already lapsed lands EXPIRED.
+          type: string
+          format: date-time
+          pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+        markAsUsedUp:
+          description: "Terminal override: zero the remaining units and mark the container USED_UP (physically discarded)."
+          type: boolean
+        printedExpiry:
+          anyOf:
+            - type: string
+              format: date-time
+              pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+            - type: "null"
+        dosesRemaining:
+          description: Absolute remaining-unit correction (0–1000). Clamped server-side to the item's `unitsTotal`; the canonical
+            state machine re-derives the state (0 ⇒ USED_UP).
+          type: integer
+          minimum: 0
+          maximum: 1000
+        notes:
+          anyOf:
+            - type: string
+              maxLength: 200
+            - type: "null"
+      description: "Per-item inventory mutation: manual first-use, used-up override, printed-expiry correction, absolute
+        remaining-unit correction, notes. Every field is optional and commutative."
     MedicationExtractRequest:
       type: object
       properties:
@@ -8264,6 +8487,13 @@ components:
               maximum: 9007199254740991
             - type: "null"
           description: Doses per pen / vial for inventory tracking. NULL = inventory tracking off.
+        unitsPerDose:
+          type: integer
+          minimum: -9007199254740991
+          maximum: 9007199254740991
+          description: v1.16.10 — inventory units one dose consumes (e.g. 2 tablets of 2 mg for a 4 mg dose). Default 1. The
+            intake consumption hook decrements this many units per taken dose; dose-derived readouts divide unit counts
+            by it.
         active:
           type: boolean
         notificationsEnabled:
@@ -8372,6 +8602,7 @@ components:
         - dose
         - treatmentClass
         - dosesPerUnit
+        - unitsPerDose
         - active
         - notificationsEnabled
         - liveActivityEnabled
@@ -8449,6 +8680,13 @@ components:
               maximum: 9007199254740991
             - type: "null"
           description: Doses per pen / vial for inventory tracking. NULL = inventory tracking off.
+        unitsPerDose:
+          type: integer
+          minimum: -9007199254740991
+          maximum: 9007199254740991
+          description: v1.16.10 — inventory units one dose consumes (e.g. 2 tablets of 2 mg for a 4 mg dose). Default 1. The
+            intake consumption hook decrements this many units per taken dose; dose-derived readouts divide unit counts
+            by it.
         active:
           type: boolean
         notificationsEnabled:
@@ -8542,6 +8780,7 @@ components:
         - dose
         - treatmentClass
         - dosesPerUnit
+        - unitsPerDose
         - active
         - notificationsEnabled
         - liveActivityEnabled
@@ -8702,6 +8941,200 @@ components:
         - data
         - error
       additionalProperties: false
+    ListMedicationInventoryResponse:
+      type: object
+      properties:
+        data:
+          type: object
+          properties:
+            items:
+              type: array
+              items:
+                $ref: "#/components/schemas/MedicationInventoryItem"
+            meta:
+              type: object
+              properties:
+                total:
+                  type: integer
+                  minimum: 0
+                  maximum: 9007199254740991
+              required:
+                - total
+              additionalProperties: false
+          required:
+            - items
+            - meta
+          additionalProperties: false
+        error:
+          type: "null"
+        meta:
+          type: object
+          properties:
+            requestId:
+              type: string
+          additionalProperties: false
+      required:
+        - data
+        - error
+      additionalProperties: false
+    MedicationInventoryItem:
+      type: object
+      properties:
+        id:
+          type: string
+        userId:
+          type: string
+        medicationId:
+          type: string
+        state:
+          type: string
+          enum:
+            - ACTIVE
+            - IN_USE
+            - EXPIRED
+            - USED_UP
+          description: Container lifecycle state. ACTIVE = unopened; IN_USE = opened (30-day in-use clock running); EXPIRED =
+            printed expiry or in-use window lapsed with units left; USED_UP = drained (terminal).
+        containerType:
+          type: string
+          enum:
+            - PEN
+            - AMPOULE
+            - BLISTER
+            - INHALER
+            - BOTTLE
+            - OTHER
+          description: Kind of physical container (PEN / AMPOULE / BLISTER / INHALER / BOTTLE / OTHER). Display-level
+            classification; defaults to OTHER.
+        unitsTotal:
+          type: integer
+          minimum: -9007199254740991
+          maximum: 9007199254740991
+          description: Units the container shipped with (tablets / ampoules / puffs; 1–1000). Dose-derived readouts divide by the
+            medication's `unitsPerDose`.
+        unitsRemaining:
+          type: integer
+          minimum: -9007199254740991
+          maximum: 9007199254740991
+          description: Units left in the container. Decremented by the intake consumption hook (FEFO with spillover across
+            containers); refunded when a taken dose is skipped, edited away, or deleted.
+        firstUseAt:
+          anyOf:
+            - type: string
+              format: date-time
+              pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+            - type: "null"
+          description: Instant the container was first used. NULL until opened; starts the 30-day in-use clock.
+        expiresAt:
+          anyOf:
+            - type: string
+              format: date-time
+              pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+            - type: "null"
+          description: Persisted MIN(firstUseAt + 30 days, printedExpiry). NULL when neither clock has started.
+        printedExpiry:
+          anyOf:
+            - type: string
+              format: date-time
+              pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+            - type: "null"
+        purchasedAt:
+          anyOf:
+            - type: string
+              format: date-time
+              pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+            - type: "null"
+        notes:
+          anyOf:
+            - type: string
+            - type: "null"
+        createdAt:
+          type: string
+          format: date-time
+          pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+        updatedAt:
+          type: string
+          format: date-time
+          pattern: ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d(?:\.\d+)?)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$
+      required:
+        - id
+        - userId
+        - medicationId
+        - state
+        - containerType
+        - unitsTotal
+        - unitsRemaining
+        - firstUseAt
+        - expiresAt
+        - printedExpiry
+        - purchasedAt
+        - notes
+        - createdAt
+        - updatedAt
+      additionalProperties: false
+      description: One supply container (pen / blister pack / bottle) of a medication. Counts UNITS — the medication's
+        `unitsPerDose` maps units to doses. The intake write paths consume from the open container first, then
+        first-expiry-first-out over unopened stock.
+    CreateMedicationInventoryItemResponse:
+      type: object
+      properties:
+        data:
+          $ref: "#/components/schemas/MedicationInventoryItem"
+        error:
+          type: "null"
+        meta:
+          type: object
+          properties:
+            requestId:
+              type: string
+          additionalProperties: false
+      required:
+        - data
+        - error
+      additionalProperties: false
+    UpdateMedicationInventoryItemResponse:
+      type: object
+      properties:
+        data:
+          $ref: "#/components/schemas/MedicationInventoryItem"
+        error:
+          type: "null"
+        meta:
+          type: object
+          properties:
+            requestId:
+              type: string
+          additionalProperties: false
+      required:
+        - data
+        - error
+      additionalProperties: false
+    DeleteMedicationInventoryItemResponse:
+      type: object
+      properties:
+        data:
+          type: object
+          properties:
+            id:
+              type: string
+            deleted:
+              type: boolean
+          required:
+            - id
+            - deleted
+          additionalProperties: false
+        error:
+          type: "null"
+        meta:
+          type: object
+          properties:
+            requestId:
+              type: string
+          additionalProperties: false
+      required:
+        - data
+        - error
+      additionalProperties: false
     MedicationExtractResponse:
       type: object
       properties:
@@ -12887,6 +13320,13 @@ components:
               maximum: 9007199254740991
             - type: "null"
           description: Doses per pen / vial for inventory tracking. NULL = inventory tracking off.
+        unitsPerDose:
+          type: integer
+          minimum: -9007199254740991
+          maximum: 9007199254740991
+          description: v1.16.10 — inventory units one dose consumes (e.g. 2 tablets of 2 mg for a 4 mg dose). Default 1. The
+            intake consumption hook decrements this many units per taken dose; dose-derived readouts divide unit counts
+            by it.
         active:
           type: boolean
         notificationsEnabled:
@@ -12978,6 +13418,7 @@ components:
         - dose
         - treatmentClass
         - dosesPerUnit
+        - unitsPerDose
         - active
         - notificationsEnabled
         - liveActivityEnabled
diff --git a/messages/de.json b/messages/de.json
index 008dd5f5f..d49bcd2ae 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -277,6 +277,7 @@
     "hero": {
       "scoreLabel": "Health Score",
       "scoreProvisional": "Noch nicht genug Daten",
+      "scoreComputing": "Score wird berechnet …",
       "doses": {
         "summary": "{taken} von {scheduled} Dosen genommen",
         "nextAt": "Nächste um {time}",
@@ -1056,7 +1057,9 @@
           "dosesPerUnitHint": "Dosen pro Pen / Ampulle — leer lassen, wenn kein Bestand getrackt wird.",
           "injectionSiteToggle": "Injektionsstellen-Rotation",
           "injectionSiteHint": "Optionaler Rotationshelfer. Die Stelle jeder Dosis wird beim Eintragen der Einnahme erfasst.",
-          "short": "Dosis"
+          "short": "Dosis",
+          "unitsPerDoseLabel": "Einheiten pro Dosis",
+          "unitsPerDoseHint": "z. B. 2 Tabletten à 2 mg für eine 4-mg-Dosis"
         },
         "step4": {
           "title": "Über welchen Zeitraum nimmst du es?",
@@ -1585,7 +1588,7 @@
       "bestand": {
         "title": "Bestand",
         "summary": "{remaining} von {total} Dosen übrig",
-        "itemsTitle": "Pens / Ampullen",
+        "itemsTitle": "Packungen & Behälter",
         "doses": "{remaining} / {total} Dosen",
         "state": {
           "ACTIVE": "Ungeöffnet",
@@ -1594,25 +1597,39 @@
           "USED_UP": "Aufgebraucht"
         },
         "empty": "Kein Bestand erfasst.",
-        "emptyHelper": "Erfasse einen Pen oder eine Packung, um verbleibende Dosen und Reichweite zu verfolgen.",
+        "emptyHelper": "Erfasse eine Packung oder einen Behälter, um den verbleibenden Vorrat und die Reichweite zu verfolgen.",
         "emptyCta": "Packung erfassen",
         "addButton": "Erfassen",
-        "addTitle": "Pen oder Packung erfassen",
-        "addDescription": "Lege einen neuen Vorrat mit seiner Dosenanzahl an; das Ablaufdatum ist optional.",
-        "addQuantityLabel": "Menge (Dosen / Einheiten)",
-        "addQuantityHelper": "1–100 Dosen pro Pen oder Packung.",
+        "addTitle": "Packung oder Behälter erfassen",
+        "addDescription": "Lege einen neuen Vorrat mit seiner Einheitenanzahl an; das Ablaufdatum ist optional.",
+        "addQuantityLabel": "Menge (Einheiten)",
+        "addQuantityHelper": "1–1000 Einheiten pro Packung oder Behälter.",
         "addExpiryLabel": "Ablaufdatum (optional)",
         "addSubmit": "Erfassen",
         "addSuccess": "Bestand erfasst.",
         "addFailed": "Bestand konnte nicht erfasst werden.",
         "adjustButton": "Anpassen",
         "adjustTitle": "Bestand korrigieren",
-        "adjustDescription": "Setze die verbleibenden Dosen neu — für Korrekturen oder eine Entnahme. 0 markiert den Vorrat als aufgebraucht.",
-        "adjustQuantityLabel": "Verbleibende Dosen",
-        "adjustHelper": "Kapazität: {total} Dosen.",
+        "adjustDescription": "Setze die verbleibenden Einheiten neu — für Korrekturen oder eine Entnahme. 0 markiert den Vorrat als aufgebraucht.",
+        "adjustQuantityLabel": "Verbleibende Einheiten",
+        "adjustHelper": "Kapazität: {total} Einheiten.",
         "adjustSubmit": "Speichern",
         "adjustSuccess": "Bestand aktualisiert.",
-        "adjustFailed": "Bestand konnte nicht aktualisiert werden."
+        "adjustFailed": "Bestand konnte nicht aktualisiert werden.",
+        "containerTypeLabel": "Behälterart",
+        "containerType": {
+          "PEN": "Pen",
+          "AMPOULE": "Ampulle",
+          "BLISTER": "Tablettenpackung",
+          "INHALER": "Inhalator",
+          "BOTTLE": "Flasche",
+          "OTHER": "Sonstiges"
+        },
+        "unitsDetail": "{remaining} / {total} Einheiten",
+        "quantityModeDoses": "Dosen",
+        "quantityModeUnits": "Einheiten",
+        "quantityInUnits": "= {units} Einheiten",
+        "quantityInDoses": "≈ {doses} Dosen"
       },
       "erweitert": {
         "group": {
diff --git a/messages/en.json b/messages/en.json
index 891a06406..e0c9d9a60 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -277,6 +277,7 @@
     "hero": {
       "scoreLabel": "Health Score",
       "scoreProvisional": "Not enough data yet",
+      "scoreComputing": "Calculating score …",
       "doses": {
         "summary": "{taken} of {scheduled} doses taken",
         "nextAt": "Next at {time}",
@@ -1056,7 +1057,9 @@
           "dosesPerUnitHint": "Doses per pen / vial — leave empty for no inventory tracking.",
           "injectionSiteToggle": "Injection-site rotation",
           "injectionSiteHint": "Optional rotation guide. The site for each dose is recorded when you log the intake.",
-          "short": "Dose"
+          "short": "Dose",
+          "unitsPerDoseLabel": "Units per dose",
+          "unitsPerDoseHint": "e.g. 2 tablets of 2 mg for a 4 mg dose"
         },
         "step4": {
           "title": "Over what period are you taking it?",
@@ -1585,7 +1588,7 @@
       "bestand": {
         "title": "Supply",
         "summary": "{remaining} of {total} doses remaining",
-        "itemsTitle": "Pens / vials",
+        "itemsTitle": "Packs & containers",
         "doses": "{remaining} / {total} doses",
         "state": {
           "ACTIVE": "Unopened",
@@ -1594,25 +1597,39 @@
           "USED_UP": "Used up"
         },
         "empty": "No supply recorded.",
-        "emptyHelper": "Register a pen or pack to track doses remaining and weeks of supply.",
+        "emptyHelper": "Register a pack or container to track remaining supply and runway.",
         "emptyCta": "Register a pack",
         "addButton": "Register",
-        "addTitle": "Register a pen or pack",
-        "addDescription": "Record a new supply with its dose count; the expiry date is optional.",
-        "addQuantityLabel": "Quantity (doses / units)",
-        "addQuantityHelper": "1–100 doses per pen or pack.",
+        "addTitle": "Register a pack or container",
+        "addDescription": "Record a new supply with its unit count; the expiry date is optional.",
+        "addQuantityLabel": "Quantity (units)",
+        "addQuantityHelper": "1–1000 units per pack or container.",
         "addExpiryLabel": "Expiry date (optional)",
         "addSubmit": "Register",
         "addSuccess": "Supply registered.",
         "addFailed": "The supply could not be registered.",
         "adjustButton": "Adjust",
         "adjustTitle": "Correct stock",
-        "adjustDescription": "Set the remaining doses — for corrections or a withdrawal. 0 marks the item as used up.",
-        "adjustQuantityLabel": "Remaining doses",
-        "adjustHelper": "Capacity: {total} doses.",
+        "adjustDescription": "Set the remaining units — for corrections or a withdrawal. 0 marks the item as used up.",
+        "adjustQuantityLabel": "Remaining units",
+        "adjustHelper": "Capacity: {total} units.",
         "adjustSubmit": "Save",
         "adjustSuccess": "Stock updated.",
-        "adjustFailed": "The stock could not be updated."
+        "adjustFailed": "The stock could not be updated.",
+        "containerTypeLabel": "Container type",
+        "containerType": {
+          "PEN": "Pen",
+          "AMPOULE": "Ampoule",
+          "BLISTER": "Tablet pack",
+          "INHALER": "Inhaler",
+          "BOTTLE": "Bottle",
+          "OTHER": "Other"
+        },
+        "unitsDetail": "{remaining} / {total} units",
+        "quantityModeDoses": "Doses",
+        "quantityModeUnits": "Units",
+        "quantityInUnits": "= {units} units",
+        "quantityInDoses": "≈ {doses} doses"
       },
       "erweitert": {
         "group": {
diff --git a/messages/es.json b/messages/es.json
index 06537b0b8..6413beec0 100644
--- a/messages/es.json
+++ b/messages/es.json
@@ -277,6 +277,7 @@
     "hero": {
       "scoreLabel": "Health Score",
       "scoreProvisional": "Aún no hay datos suficientes",
+      "scoreComputing": "Calculando la puntuación …",
       "doses": {
         "summary": "{taken} de {scheduled} dosis tomadas",
         "nextAt": "Próxima a las {time}",
@@ -1056,7 +1057,9 @@
           "dosesPerUnitHint": "Dosis por pluma / vial — déjalo vacío para no controlar el inventario.",
           "injectionSiteToggle": "Rotación del sitio de inyección",
           "injectionSiteHint": "Guía de rotación opcional. El sitio de cada dosis se registra al anotar la toma.",
-          "short": "Dosis"
+          "short": "Dosis",
+          "unitsPerDoseLabel": "Unidades por dosis",
+          "unitsPerDoseHint": "p. ej., 2 comprimidos de 2 mg para una dosis de 4 mg"
         },
         "step4": {
           "title": "¿Durante qué periodo lo tomas?",
@@ -1585,7 +1588,7 @@
       "bestand": {
         "title": "Existencias",
         "summary": "{remaining} de {total} dosis restantes",
-        "itemsTitle": "Plumas / viales",
+        "itemsTitle": "Envases y recipientes",
         "doses": "{remaining} / {total} dosis",
         "state": {
           "ACTIVE": "Sin abrir",
@@ -1594,25 +1597,39 @@
           "USED_UP": "Agotado"
         },
         "empty": "No hay existencias registradas.",
-        "emptyHelper": "Registra una pluma o un paquete para hacer seguimiento de las dosis restantes y las semanas de suministro.",
+        "emptyHelper": "Registra un envase o recipiente para hacer seguimiento de las existencias restantes y la autonomía.",
         "emptyCta": "Registrar un envase",
         "addButton": "Registrar",
-        "addTitle": "Registrar una pluma o un envase",
-        "addDescription": "Registra una nueva existencia con su número de dosis; la fecha de caducidad es opcional.",
-        "addQuantityLabel": "Cantidad (dosis / unidades)",
-        "addQuantityHelper": "1–100 dosis por pluma o envase.",
+        "addTitle": "Registrar un envase o recipiente",
+        "addDescription": "Registra una nueva existencia con su número de unidades; la fecha de caducidad es opcional.",
+        "addQuantityLabel": "Cantidad (unidades)",
+        "addQuantityHelper": "1–1000 unidades por envase o recipiente.",
         "addExpiryLabel": "Fecha de caducidad (opcional)",
         "addSubmit": "Registrar",
         "addSuccess": "Existencias registradas.",
         "addFailed": "No se pudieron registrar las existencias.",
         "adjustButton": "Ajustar",
         "adjustTitle": "Corregir existencias",
-        "adjustDescription": "Establece las dosis restantes — para correcciones o una retirada. 0 marca el envase como agotado.",
-        "adjustQuantityLabel": "Dosis restantes",
-        "adjustHelper": "Capacidad: {total} dosis.",
+        "adjustDescription": "Establece las unidades restantes — para correcciones o una retirada. 0 marca el envase como agotado.",
+        "adjustQuantityLabel": "Unidades restantes",
+        "adjustHelper": "Capacidad: {total} unidades.",
         "adjustSubmit": "Guardar",
         "adjustSuccess": "Existencias actualizadas.",
-        "adjustFailed": "No se pudieron actualizar las existencias."
+        "adjustFailed": "No se pudieron actualizar las existencias.",
+        "containerTypeLabel": "Tipo de envase",
+        "containerType": {
+          "PEN": "Pluma",
+          "AMPOULE": "Ampolla",
+          "BLISTER": "Envase de comprimidos",
+          "INHALER": "Inhalador",
+          "BOTTLE": "Frasco",
+          "OTHER": "Otro"
+        },
+        "unitsDetail": "{remaining} / {total} unidades",
+        "quantityModeDoses": "Dosis",
+        "quantityModeUnits": "Unidades",
+        "quantityInUnits": "= {units} unidades",
+        "quantityInDoses": "≈ {doses} dosis"
       },
       "erweitert": {
         "group": {
diff --git a/messages/fr.json b/messages/fr.json
index 445d9e1f3..19487aaa5 100644
--- a/messages/fr.json
+++ b/messages/fr.json
@@ -277,6 +277,7 @@
     "hero": {
       "scoreLabel": "Health Score",
       "scoreProvisional": "Pas encore assez de données",
+      "scoreComputing": "Calcul du score en cours …",
       "doses": {
         "summary": "{taken} dose(s) prise(s) sur {scheduled}",
         "nextAt": "Prochaine à {time}",
@@ -1056,7 +1057,9 @@
           "dosesPerUnitHint": "Doses par stylo / flacon — laisser vide pour ne pas suivre le stock.",
           "injectionSiteToggle": "Rotation des sites d'injection",
           "injectionSiteHint": "Guide de rotation facultatif. Le site de chaque dose est enregistré lors de la saisie de la prise.",
-          "short": "Dose"
+          "short": "Dose",
+          "unitsPerDoseLabel": "Unités par dose",
+          "unitsPerDoseHint": "p. ex. 2 comprimés de 2 mg pour une dose de 4 mg"
         },
         "step4": {
           "title": "Sur quelle période le prenez-vous ?",
@@ -1585,7 +1588,7 @@
       "bestand": {
         "title": "Stock",
         "summary": "{remaining} doses restantes sur {total}",
-        "itemsTitle": "Stylos / flacons",
+        "itemsTitle": "Boîtes et contenants",
         "doses": "{remaining} / {total} doses",
         "state": {
           "ACTIVE": "Non ouvert",
@@ -1594,25 +1597,39 @@
           "USED_UP": "Épuisé"
         },
         "empty": "Aucun stock enregistré.",
-        "emptyHelper": "Enregistrez un stylo ou une boîte pour suivre les doses restantes et l'autonomie.",
+        "emptyHelper": "Enregistrez une boîte ou un contenant pour suivre le stock restant et l'autonomie.",
         "emptyCta": "Enregistrer une boîte",
         "addButton": "Enregistrer",
-        "addTitle": "Enregistrer un stylo ou une boîte",
-        "addDescription": "Enregistrez un nouveau stock avec son nombre de doses ; la date de péremption est facultative.",
-        "addQuantityLabel": "Quantité (doses / unités)",
-        "addQuantityHelper": "1–100 doses par stylo ou boîte.",
+        "addTitle": "Enregistrer une boîte ou un contenant",
+        "addDescription": "Enregistrez un nouveau stock avec son nombre d'unités ; la date de péremption est facultative.",
+        "addQuantityLabel": "Quantité (unités)",
+        "addQuantityHelper": "1–1000 unités par boîte ou contenant.",
         "addExpiryLabel": "Date de péremption (facultatif)",
         "addSubmit": "Enregistrer",
         "addSuccess": "Stock enregistré.",
         "addFailed": "Le stock n'a pas pu être enregistré.",
         "adjustButton": "Ajuster",
         "adjustTitle": "Corriger le stock",
-        "adjustDescription": "Définissez les doses restantes — pour une correction ou un prélèvement. 0 marque l'article comme épuisé.",
-        "adjustQuantityLabel": "Doses restantes",
-        "adjustHelper": "Capacité : {total} doses.",
+        "adjustDescription": "Définissez les unités restantes — pour une correction ou un prélèvement. 0 marque l'article comme épuisé.",
+        "adjustQuantityLabel": "Unités restantes",
+        "adjustHelper": "Capacité : {total} unités.",
         "adjustSubmit": "Enregistrer",
         "adjustSuccess": "Stock mis à jour.",
-        "adjustFailed": "Le stock n'a pas pu être mis à jour."
+        "adjustFailed": "Le stock n'a pas pu être mis à jour.",
+        "containerTypeLabel": "Type de contenant",
+        "containerType": {
+          "PEN": "Stylo",
+          "AMPOULE": "Ampoule",
+          "BLISTER": "Plaquette de comprimés",
+          "INHALER": "Inhalateur",
+          "BOTTLE": "Flacon",
+          "OTHER": "Autre"
+        },
+        "unitsDetail": "{remaining} / {total} unités",
+        "quantityModeDoses": "Doses",
+        "quantityModeUnits": "Unités",
+        "quantityInUnits": "= {units} unités",
+        "quantityInDoses": "≈ {doses} doses"
       },
       "erweitert": {
         "group": {
diff --git a/messages/it.json b/messages/it.json
index a71112349..097725139 100644
--- a/messages/it.json
+++ b/messages/it.json
@@ -277,6 +277,7 @@
     "hero": {
       "scoreLabel": "Health Score",
       "scoreProvisional": "Dati ancora insufficienti",
+      "scoreComputing": "Calcolo del punteggio in corso …",
       "doses": {
         "summary": "{taken} dosi assunte su {scheduled}",
         "nextAt": "Prossima alle {time}",
@@ -1056,7 +1057,9 @@
           "dosesPerUnitHint": "Dosi per penna / fiala — lascia vuoto per non tracciare le scorte.",
           "injectionSiteToggle": "Rotazione del sito di iniezione",
           "injectionSiteHint": "Guida alla rotazione facoltativa. Il sito di ogni dose viene registrato al momento della registrazione dell'assunzione.",
-          "short": "Dose"
+          "short": "Dose",
+          "unitsPerDoseLabel": "Unità per dose",
+          "unitsPerDoseHint": "ad es. 2 compresse da 2 mg per una dose da 4 mg"
         },
         "step4": {
           "title": "Per quanto tempo lo assumi?",
@@ -1585,7 +1588,7 @@
       "bestand": {
         "title": "Scorta",
         "summary": "{remaining} dosi rimanenti su {total}",
-        "itemsTitle": "Penne / flaconi",
+        "itemsTitle": "Confezioni e contenitori",
         "doses": "{remaining} / {total} dosi",
         "state": {
           "ACTIVE": "Non aperto",
@@ -1594,25 +1597,39 @@
           "USED_UP": "Esaurito"
         },
         "empty": "Nessuna scorta registrata.",
-        "emptyHelper": "Registra una penna o una confezione per monitorare le dosi rimanenti e l'autonomia.",
+        "emptyHelper": "Registra una confezione o un contenitore per monitorare la scorta rimanente e l'autonomia.",
         "emptyCta": "Registra una confezione",
         "addButton": "Registra",
-        "addTitle": "Registra una penna o una confezione",
-        "addDescription": "Registra una nuova scorta con il numero di dosi; la data di scadenza è facoltativa.",
-        "addQuantityLabel": "Quantità (dosi / unità)",
-        "addQuantityHelper": "1–100 dosi per penna o confezione.",
+        "addTitle": "Registra una confezione o un contenitore",
+        "addDescription": "Registra una nuova scorta con il numero di unità; la data di scadenza è facoltativa.",
+        "addQuantityLabel": "Quantità (unità)",
+        "addQuantityHelper": "1–1000 unità per confezione o contenitore.",
         "addExpiryLabel": "Data di scadenza (facoltativa)",
         "addSubmit": "Registra",
         "addSuccess": "Scorta registrata.",
         "addFailed": "Impossibile registrare la scorta.",
         "adjustButton": "Correggi",
         "adjustTitle": "Correggi la scorta",
-        "adjustDescription": "Imposta le dosi rimanenti — per correzioni o un prelievo. 0 segna la scorta come esaurita.",
-        "adjustQuantityLabel": "Dosi rimanenti",
-        "adjustHelper": "Capacità: {total} dosi.",
+        "adjustDescription": "Imposta le unità rimanenti — per correzioni o un prelievo. 0 segna la scorta come esaurita.",
+        "adjustQuantityLabel": "Unità rimanenti",
+        "adjustHelper": "Capacità: {total} unità.",
         "adjustSubmit": "Salva",
         "adjustSuccess": "Scorta aggiornata.",
-        "adjustFailed": "Impossibile aggiornare la scorta."
+        "adjustFailed": "Impossibile aggiornare la scorta.",
+        "containerTypeLabel": "Tipo di contenitore",
+        "containerType": {
+          "PEN": "Penna",
+          "AMPOULE": "Fiala",
+          "BLISTER": "Confezione di compresse",
+          "INHALER": "Inalatore",
+          "BOTTLE": "Flacone",
+          "OTHER": "Altro"
+        },
+        "unitsDetail": "{remaining} / {total} unità",
+        "quantityModeDoses": "Dosi",
+        "quantityModeUnits": "Unità",
+        "quantityInUnits": "= {units} unità",
+        "quantityInDoses": "≈ {doses} dosi"
       },
       "erweitert": {
         "group": {
diff --git a/messages/pl.json b/messages/pl.json
index 18ac910b5..61fb2f695 100644
--- a/messages/pl.json
+++ b/messages/pl.json
@@ -277,6 +277,7 @@
     "hero": {
       "scoreLabel": "Health Score",
       "scoreProvisional": "Za mało danych",
+      "scoreComputing": "Trwa obliczanie wyniku …",
       "doses": {
         "summary": "Przyjęto {taken} z {scheduled} dawek",
         "nextAt": "Następna o {time}",
@@ -1056,7 +1057,9 @@
           "dosesPerUnitHint": "Dawki na wstrzykiwacz / fiolkę — zostaw puste, aby nie śledzić zapasów.",
           "injectionSiteToggle": "Rotacja miejsc wstrzyknięcia",
           "injectionSiteHint": "Opcjonalny przewodnik rotacji. Miejsce każdej dawki zapisywane jest przy rejestrowaniu przyjęcia.",
-          "short": "Dawka"
+          "short": "Dawka",
+          "unitsPerDoseLabel": "Jednostki na dawkę",
+          "unitsPerDoseHint": "np. 2 tabletki po 2 mg na dawkę 4 mg"
         },
         "step4": {
           "title": "Przez jaki okres go przyjmujesz?",
@@ -1585,7 +1588,7 @@
       "bestand": {
         "title": "Zapas",
         "summary": "Pozostało {remaining} z {total} dawek",
-        "itemsTitle": "Wstrzykiwacze / fiolki",
+        "itemsTitle": "Opakowania i pojemniki",
         "doses": "{remaining} / {total} dawek",
         "state": {
           "ACTIVE": "Nieotwarte",
@@ -1594,25 +1597,39 @@
           "USED_UP": "Zużyte"
         },
         "empty": "Nie zarejestrowano zapasu.",
-        "emptyHelper": "Zarejestruj wstrzykiwacz lub opakowanie, aby śledzić pozostałe dawki i zapas na tygodnie.",
+        "emptyHelper": "Zarejestruj opakowanie lub pojemnik, aby śledzić pozostały zapas i jego wystarczalność.",
         "emptyCta": "Zarejestruj opakowanie",
         "addButton": "Zarejestruj",
-        "addTitle": "Zarejestruj wstrzykiwacz lub opakowanie",
-        "addDescription": "Zapisz nowy zapas z liczbą dawek; data ważności jest opcjonalna.",
-        "addQuantityLabel": "Ilość (dawki / jednostki)",
-        "addQuantityHelper": "1–100 dawek na wstrzykiwacz lub opakowanie.",
+        "addTitle": "Zarejestruj opakowanie lub pojemnik",
+        "addDescription": "Zapisz nowy zapas z liczbą jednostek; data ważności jest opcjonalna.",
+        "addQuantityLabel": "Ilość (jednostki)",
+        "addQuantityHelper": "1–1000 jednostek na opakowanie lub pojemnik.",
         "addExpiryLabel": "Data ważności (opcjonalnie)",
         "addSubmit": "Zarejestruj",
         "addSuccess": "Zapas zarejestrowany.",
         "addFailed": "Nie udało się zarejestrować zapasu.",
         "adjustButton": "Skoryguj",
         "adjustTitle": "Skoryguj zapas",
-        "adjustDescription": "Ustaw pozostałe dawki — przy korekcie lub pobraniu. 0 oznacza zapas jako zużyty.",
-        "adjustQuantityLabel": "Pozostałe dawki",
-        "adjustHelper": "Pojemność: {total} dawek.",
+        "adjustDescription": "Ustaw pozostałe jednostki — przy korekcie lub pobraniu. 0 oznacza zapas jako zużyty.",
+        "adjustQuantityLabel": "Pozostałe jednostki",
+        "adjustHelper": "Pojemność: {total} jednostek.",
         "adjustSubmit": "Zapisz",
         "adjustSuccess": "Zapas zaktualizowany.",
-        "adjustFailed": "Nie udało się zaktualizować zapasu."
+        "adjustFailed": "Nie udało się zaktualizować zapasu.",
+        "containerTypeLabel": "Rodzaj pojemnika",
+        "containerType": {
+          "PEN": "Wstrzykiwacz",
+          "AMPOULE": "Ampułka",
+          "BLISTER": "Opakowanie tabletek",
+          "INHALER": "Inhalator",
+          "BOTTLE": "Butelka",
+          "OTHER": "Inne"
+        },
+        "unitsDetail": "{remaining} / {total} jednostek",
+        "quantityModeDoses": "Dawki",
+        "quantityModeUnits": "Jednostki",
+        "quantityInUnits": "= {units} jednostek",
+        "quantityInDoses": "≈ {doses} dawek"
       },
       "erweitert": {
         "group": {
diff --git a/prisma/migrations/0149_v11610_inventory_units/migration.sql b/prisma/migrations/0149_v11610_inventory_units/migration.sql
new file mode 100644
index 000000000..2c56f2dad
--- /dev/null
+++ b/prisma/migrations/0149_v11610_inventory_units/migration.sql
@@ -0,0 +1,36 @@
+-- v1.16.10 — multi-unit inventory consumption.
+--
+-- `units_per_dose` (medications): how many inventory UNITS one dose
+-- consumes (2 × 2 mg tablets for a 4 mg dose). Default 1 keeps every
+-- existing medication on the one-unit-per-dose behaviour.
+--
+-- `container_type` (medication_inventory_items): what kind of physical
+-- container the item is (pen / ampoule / blister pack / inhaler /
+-- bottle). Display-level only. Backfilled PEN for items whose
+-- medication is an INJECTION (the pre-v1.16.10 surface was pen-only),
+-- OTHER for everything else.
+--
+-- `inventory_consumption` (medication_intake_events): the per-event
+-- consumption stamp `[{itemId, units}]` — the exactly-once gate for
+-- the consume hook and the refund ledger for the restore hook. NULL =
+-- never consumed (pending / skipped / pre-v1.16.10 rows).
+--
+-- The Prisma fields `dosesTotal` / `dosesRemaining` are renamed to
+-- `unitsTotal` / `unitsRemaining` at the client level only; the DB
+-- columns keep their names via @map — zero data migration.
+
+CREATE TYPE "medication_container_type" AS ENUM ('PEN', 'AMPOULE', 'BLISTER', 'INHALER', 'BOTTLE', 'OTHER');
+
+ALTER TABLE "medications" ADD COLUMN "units_per_dose" INTEGER NOT NULL DEFAULT 1;
+
+ALTER TABLE "medication_inventory_items" ADD COLUMN "container_type" "medication_container_type" NOT NULL DEFAULT 'OTHER';
+
+ALTER TABLE "medication_intake_events" ADD COLUMN "inventory_consumption" JSONB;
+
+-- Backfill: every existing item was registered through the pen-framed
+-- surface; items on injection medications are pens.
+UPDATE "medication_inventory_items" i
+SET "container_type" = 'PEN'
+FROM "medications" m
+WHERE i."medication_id" = m."id"
+  AND m."delivery_form" = 'INJECTION';
diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index 439ea78ad..099674630 100644
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -1261,6 +1261,12 @@ model Medication {
   /// (Mounjaro KwikPen = 4, Ozempic 0.25/0.5 mg = 4, Wegovy single-dose
   /// pen = 1). NULL = inventory tracking off.
   dosesPerUnit         Int?               @map("doses_per_unit")
+  /// v1.16.10 — units consumed per dose. The inventory items count UNITS
+  /// (tablets, ampoules, puffs); a single dose may consume several of
+  /// them (2 × 2 mg tablets for a 4 mg dose). The intake consumption
+  /// hook multiplies by this factor; dose-level readouts divide by it.
+  /// Default 1 = one unit per dose (the overwhelmingly common case).
+  unitsPerDose         Int                @default(1) @map("units_per_dose")
   active               Boolean            @default(true)
   notificationsEnabled Boolean            @default(true) @map("notifications_enabled")
   pausedAt             DateTime?          @map("paused_at")
@@ -1599,6 +1605,15 @@ model MedicationIntakeEvent {
   /// log time (half tablet, titration day). NULL = the configured
   /// medication / schedule dose applies; read paths fall back to it.
   doseTaken      String?        @map("dose_taken")
+  /// v1.16.10 — inventory consumption stamp: `[{itemId, units}]` for the
+  /// containers this taken event decremented. NULL = never consumed
+  /// (pending / skipped / pre-v1.16.10 rows). The stamp is the exactly-
+  /// once gate for the consume hook (a stamped row never decrements
+  /// again, however often a sync replays it) and the refund ledger for
+  /// the restore hook (taken → skipped / deleted refunds per item). The
+  /// stamp freezes history: editing `Medication.unitsPerDose` later
+  /// never changes what an already-taken dose consumed.
+  inventoryConsumption Json?    @map("inventory_consumption")
   // v1.7.0 sync — server-set mutation timestamp. The model had no
   // `updatedAt`; the offline-sync keyset feed orders on it, so it is
   // added here. `@updatedAt` makes Prisma maintain it on every write.
@@ -1706,16 +1721,38 @@ enum MedicationInventoryState {
   @@map("medication_inventory_state")
 }
 
+/// v1.16.10 — what kind of physical container an inventory item is.
+/// Display-level only (no state-machine behaviour hangs off it); the
+/// register dialog defaults it from the medication's delivery form
+/// (INJECTION → PEN, ORAL → BLISTER, else OTHER).
+enum MedicationContainerType {
+  PEN
+  AMPOULE
+  BLISTER
+  INHALER
+  BOTTLE
+  OTHER
+
+  @@map("medication_container_type")
+}
+
 model MedicationInventoryItem {
   id             String                   @id @default(cuid())
   userId         String                   @map("user_id")
   medicationId   String                   @map("medication_id")
   state          MedicationInventoryState @default(ACTIVE)
-  /// Doses the pen / vial shipped with. Mounjaro KwikPen = 4,
-  /// Trulicity single-dose = 1, Byetta = 60.
-  dosesTotal     Int                      @map("doses_total")
-  /// Remaining doses; decremented by the intake hook.
-  dosesRemaining Int                      @map("doses_remaining")
+  /// v1.16.10 — container kind (pen / ampoule / blister pack / …).
+  /// Backfilled PEN for items on INJECTION medications, OTHER otherwise.
+  containerType  MedicationContainerType  @default(OTHER) @map("container_type")
+  /// Units the container shipped with (v1.16.10 — renamed from
+  /// `dosesTotal`; the DB column stays `doses_total`). A unit is one
+  /// tablet / ampoule / puff; `Medication.unitsPerDose` maps units to
+  /// doses. Mounjaro KwikPen = 4, Trulicity single-dose = 1.
+  unitsTotal     Int                      @map("doses_total")
+  /// Remaining units; decremented by the intake consumption hook
+  /// (v1.16.10 — renamed from `dosesRemaining`; column stays
+  /// `doses_remaining`).
+  unitsRemaining Int                      @map("doses_remaining")
   /// NULL until the pen is first opened. Sets the 30-day in-use
   /// clock per EMA EPAR §6.3.
   firstUseAt     DateTime?                @map("first_use_at")
diff --git a/src/__tests__/inventory-write-isolation.test.ts b/src/__tests__/inventory-write-isolation.test.ts
new file mode 100644
index 000000000..4c02bc53a
--- /dev/null
+++ b/src/__tests__/inventory-write-isolation.test.ts
@@ -0,0 +1,79 @@
+/**
+ * v1.16.10 — inventory write-path isolation guard.
+ *
+ * The consumption stamp on `MedicationIntakeEvent.inventoryConsumption`
+ * is only an exactly-once ledger as long as EVERY stock movement flows
+ * through `src/lib/medications/inventory/consumption.ts` (intake-driven
+ * consume / restore) or the dedicated inventory surfaces (the CRUD
+ * routes, the create-input builder, and the expire cron in
+ * `service.ts`). A `medicationInventoryItem` write sprinkled into some
+ * future intake path would bypass the stamp and re-open the
+ * double-decrement / stranded-stock class of bugs this release closed.
+ *
+ * This test walks every TypeScript / TSX file under `src/` (excluding
+ * tests + generated code) and asserts that no file outside the
+ * allowlist invokes a Prisma write method on `medicationInventoryItem`.
+ * Reads (`findFirst`, `findMany`, …) stay legal everywhere.
+ */
+import { describe, it, expect } from "vitest";
+import { readFileSync, readdirSync, statSync } from "node:fs";
+import { join, relative, sep } from "node:path";
+
+const ROOT = join(__dirname, "../..");
+const SRC = join(ROOT, "src");
+
+const SKIP_DIRS = new Set(["__tests__", "node_modules", ".next", "generated"]);
+
+/**
+ * Files allowed to write `medicationInventoryItem` rows:
+ *   - the consumption module (intake-driven consume / restore);
+ *   - the inventory persistence helpers (expire cron `updateMany`);
+ *   - the two inventory CRUD routes (register / mutate / delete).
+ */
+const ALLOWED_WRITERS = new Set(
+  [
+    "src/lib/medications/inventory/consumption.ts",
+    "src/lib/medications/inventory/service.ts",
+    "src/app/api/medications/[id]/inventory/route.ts",
+    "src/app/api/medications/[id]/inventory/[itemId]/route.ts",
+  ].map((p) => p.split("/").join(sep)),
+);
+
+const WRITE_PATTERN =
+  /medicationInventoryItem\s*\.\s*(create|createMany|update|updateMany|upsert|delete|deleteMany)\s*\(/g;
+
+function walk(dir: string, out: string[] = []): string[] {
+  for (const name of readdirSync(dir)) {
+    if (SKIP_DIRS.has(name)) continue;
+    const p = join(dir, name);
+    const stat = statSync(p);
+    if (stat.isDirectory()) {
+      walk(p, out);
+    } else if (name.endsWith(".ts") || name.endsWith(".tsx")) {
+      out.push(p);
+    }
+  }
+  return out;
+}
+
+describe("medicationInventoryItem write isolation", () => {
+  it("no file outside the consumption module + inventory surfaces writes inventory items", () => {
+    const offenders: string[] = [];
+    for (const file of walk(SRC)) {
+      const rel = relative(ROOT, file);
+      if (ALLOWED_WRITERS.has(rel)) continue;
+      const content = readFileSync(file, "utf8");
+      if (WRITE_PATTERN.test(content)) {
+        offenders.push(rel);
+        WRITE_PATTERN.lastIndex = 0;
+      }
+    }
+    expect(offenders).toEqual([]);
+  });
+
+  it("the allowlisted writers actually exist (allowlist stays honest)", () => {
+    for (const rel of ALLOWED_WRITERS) {
+      expect(() => statSync(join(ROOT, rel))).not.toThrow();
+    }
+  });
+});
diff --git a/src/app/api/ingest/medication/__tests__/route.test.ts b/src/app/api/ingest/medication/__tests__/route.test.ts
index 629b8c247..d33c3457a 100644
--- a/src/app/api/ingest/medication/__tests__/route.test.ts
+++ b/src/app/api/ingest/medication/__tests__/route.test.ts
@@ -40,6 +40,10 @@ vi.mock("@/lib/app-settings", () => ({
 vi.mock("@/lib/rollups/medication-compliance-rollups", () => ({
   recomputeMedicationComplianceForEvent: vi.fn().mockResolvedValue(undefined),
 }));
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  consumeForIntake: vi.fn().mockResolvedValue(undefined),
+}));
+
 vi.mock("@/lib/cache/invalidate", () => ({
   invalidateUserMedications: vi.fn(),
 }));
@@ -303,4 +307,49 @@ describe("POST /api/ingest/medication — slot attribution + convergence (v1.16.
     expect(create.data.scheduledFor.getTime()).toBe(offWindow.getTime());
     expect(create.data.takenAt.getTime()).toBe(offWindow.getTime());
   });
+
+  // ── v1.16.10 — inventory consumption seam ───────────────────────────
+
+  it("consumes inventory exactly once on the landed row", async () => {
+    const { consumeForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    wireHappyPath();
+    const res = await POST(
+      postReq({
+        medicationName: "Metformin",
+        takenAt: TAKEN_0842_BERLIN.toISOString(),
+        idempotencyKey: "ha-ingest-inv-1",
+      }),
+    );
+    expect(res.status).toBe(201);
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({
+        userId: "user-1",
+        medicationId: "med-1",
+        eventId: "evt-pending-0900",
+      }),
+    );
+  });
+
+  it("an idempotency replay returns the original row without consuming", async () => {
+    const { consumeForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    wireHappyPath();
+    // The replay probe finds the original event.
+    vi.mocked(prisma.medicationIntakeEvent.findFirst).mockResolvedValue({
+      id: "evt-original",
+    } as never);
+    const res = await POST(
+      postReq({
+        medicationName: "Metformin",
+        takenAt: TAKEN_0842_BERLIN.toISOString(),
+        idempotencyKey: "ha-ingest-inv-1",
+      }),
+    );
+    expect(res.status).toBe(200);
+    expect(consumeForIntake).not.toHaveBeenCalled();
+  });
 });
diff --git a/src/app/api/ingest/medication/route.ts b/src/app/api/ingest/medication/route.ts
index dfeafa5f4..4b01a61c1 100644
--- a/src/app/api/ingest/medication/route.ts
+++ b/src/app/api/ingest/medication/route.ts
@@ -19,6 +19,7 @@ import {
   applyCanonicalSlotWrite,
   resolveSlotForWriteByBand,
 } from "@/lib/medications/scheduling/slot-upsert";
+import { consumeForIntake } from "@/lib/medications/inventory/consumption";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
 import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
 import { NextRequest, NextResponse } from "next/server";
@@ -224,6 +225,17 @@ export const POST = apiHandler(async (request: NextRequest) => {
     });
   }
 
+  // v1.16.10 — the external ingest records a take; consume inventory
+  // units. The stamp on the row keeps a retried POST exactly-once (the
+  // idempotency probe above already short-circuits the common replay).
+  await consumeForIntake({
+    client: prisma,
+    userId: apiToken.userId,
+    medicationId: medication.id,
+    eventId: event.id,
+    intakeAt: effectiveTakenAt,
+  });
+
   await auditLog("medication.ingest.external", {
     userId: apiToken.userId,
     ipAddress: ip,
diff --git a/src/app/api/insights/glp1-timeline/route.ts b/src/app/api/insights/glp1-timeline/route.ts
index 45d18cb43..306322109 100644
--- a/src/app/api/insights/glp1-timeline/route.ts
+++ b/src/app/api/insights/glp1-timeline/route.ts
@@ -82,6 +82,15 @@ export const GET = apiHandler(async (request: NextRequest) => {
         orderBy: { takenAt: "desc" },
         take: 50,
       },
+      // v1.16.10 divergence note: the stock READOUTS (glp1 details
+      // endpoint, Coach snapshot) moved to the per-item
+      // MedicationInventoryItem entities, but this timeline renders the
+      // append-only MedicationInventoryEvent LEDGER as point-in-time
+      // entries ("+2 pens purchased") — a per-item swap is not
+      // mechanical (items carry no per-mutation history). The ledger
+      // only grows through the legacy `POST /api/medications/[id]/glp1`
+      // inventory branch, so timelines on item-tracked medications show
+      // no new inventory entries.
       inventoryEvents: { orderBy: { occurredAt: "desc" }, take: 20 },
     },
   });
diff --git a/src/app/api/medications/[id]/glp1/__tests__/route.test.ts b/src/app/api/medications/[id]/glp1/__tests__/route.test.ts
index b9dfb690e..c8f10a701 100644
--- a/src/app/api/medications/[id]/glp1/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/glp1/__tests__/route.test.ts
@@ -404,10 +404,11 @@ describe("GET /api/medications/[id]/glp1 — ownership helper (F-1 C-4)", () =>
       id: "med-1",
       userId: "user-1",
       doseChanges: [],
-      inventoryEvents: [],
+      inventoryItems: [],
       intakeEvents: [],
       schedules: [],
       dosesPerUnit: null,
+      unitsPerDose: 1,
     } as never);
     const res = await GET(getReq(), {
       params: Promise.resolve({ id: "med-1" }),
@@ -428,3 +429,75 @@ describe("GET /api/medications/[id]/glp1 — ownership helper (F-1 C-4)", () =>
     expect(prisma.medication.findUnique).not.toHaveBeenCalled();
   });
 });
+
+describe("GET /api/medications/[id]/glp1 — v1.16.10 item-backed inventory", () => {
+  function getReq(): NextRequest {
+    return new NextRequest("http://localhost/api/medications/med-1/glp1");
+  }
+
+  it("sums usable inventory items and derives doses via unitsPerDose", async () => {
+    vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+    vi.mocked(prisma.medication.findUnique).mockResolvedValue({
+      id: "med-1",
+      userId: "user-1",
+      doseChanges: [],
+      intakeEvents: [],
+      schedules: [],
+      dosesPerUnit: 4,
+      unitsPerDose: 2,
+      inventoryItems: [
+        // Usable: open container with 3 units.
+        { state: "IN_USE", unitsTotal: 4, unitsRemaining: 3 },
+        // Usable: unopened container with 4 units.
+        { state: "ACTIVE", unitsTotal: 4, unitsRemaining: 4 },
+        // Not usable: drained.
+        { state: "USED_UP", unitsTotal: 4, unitsRemaining: 0 },
+        // Not usable: expired stock is not supply.
+        { state: "EXPIRED", unitsTotal: 4, unitsRemaining: 4 },
+      ],
+    } as never);
+
+    const res = await GET(getReq(), {
+      params: Promise.resolve({ id: "med-1" }),
+    });
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as {
+      data: {
+        inventory: {
+          pensRemaining: number;
+          dosesRemaining: number;
+          weeksOfSupply: number;
+          lowStock: boolean;
+        };
+      };
+    };
+    // 2 usable containers; 7 pooled units / 2 units per dose = 3 doses.
+    expect(body.data.inventory).toEqual({
+      pensRemaining: 2,
+      dosesRemaining: 3,
+      weeksOfSupply: 3,
+      lowStock: true,
+    });
+  });
+
+  it("returns a null inventory block when no items exist", async () => {
+    vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+    vi.mocked(prisma.medication.findUnique).mockResolvedValue({
+      id: "med-1",
+      userId: "user-1",
+      doseChanges: [],
+      intakeEvents: [],
+      schedules: [],
+      dosesPerUnit: null,
+      unitsPerDose: 1,
+      inventoryItems: [],
+    } as never);
+
+    const res = await GET(getReq(), {
+      params: Promise.resolve({ id: "med-1" }),
+    });
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as { data: { inventory: unknown } };
+    expect(body.data.inventory).toBeNull();
+  });
+});
diff --git a/src/app/api/medications/[id]/glp1/route.ts b/src/app/api/medications/[id]/glp1/route.ts
index a951fc643..ee887b531 100644
--- a/src/app/api/medications/[id]/glp1/route.ts
+++ b/src/app/api/medications/[id]/glp1/route.ts
@@ -54,7 +54,11 @@ export const GET = apiHandler(
       where: { id },
       include: {
         doseChanges: { orderBy: { effectiveFrom: "asc" } },
-        inventoryEvents: { orderBy: { occurredAt: "asc" } },
+        // v1.16.10 — the inventory block reads the per-item entities
+        // (the same rows the Bestand tab and the intake consumption
+        // hook move), replacing the legacy MedicationInventoryEvent
+        // running-sum ledger that no write path feeds any more.
+        inventoryItems: { orderBy: { createdAt: "asc" } },
         intakeEvents: {
           where: { takenAt: { not: null } },
           orderBy: { takenAt: "desc" },
@@ -69,25 +73,32 @@ export const GET = apiHandler(
       return apiError("Medication not found", 404);
     }
 
-    // Inventory math: running sum of every inventory event. Negative
-    // when more doses were consumed than purchased — surfaces as a
-    // low-stock warning rather than a hard error so the UI keeps
-    // working when the user backdates an inventory event.
+    // Inventory math over the per-item entities. The response shape is
+    // locked for the iOS client: `pensRemaining` = count of usable
+    // containers (ACTIVE / IN_USE with units left), `dosesRemaining` =
+    // pooled units divided by `unitsPerDose` (floored — consumption
+    // spills across containers), `weeksOfSupply` keeps the weekly-
+    // cadence approximation (the canonical GLP-1 case).
     let inventory: {
       pensRemaining: number | null;
       dosesRemaining: number | null;
       weeksOfSupply: number | null;
       lowStock: boolean;
     } | null = null;
-    if (medication.dosesPerUnit && medication.inventoryEvents.length > 0) {
-      const pens = medication.inventoryEvents.reduce(
-        (sum, ev) => sum + ev.delta,
+    if (medication.inventoryItems.length > 0) {
+      const usable = medication.inventoryItems.filter(
+        (item) =>
+          (item.state === "ACTIVE" || item.state === "IN_USE") &&
+          item.unitsRemaining > 0,
+      );
+      const unitsRemaining = usable.reduce(
+        (sum, item) => sum + item.unitsRemaining,
         0,
       );
-      const pensRemaining = Math.max(0, pens);
-      const dosesRemaining = pensRemaining * medication.dosesPerUnit;
-      // Approximate weeks-of-supply assuming weekly cadence (the
-      // canonical GLP-1 case). The Coach snapshot does the same.
+      const pensRemaining = usable.length;
+      const dosesRemaining = Math.floor(
+        unitsRemaining / Math.max(1, medication.unitsPerDose),
+      );
       const weeksOfSupply = dosesRemaining;
       const lowStock = dosesRemaining < LOW_STOCK_DOSE_THRESHOLD;
       inventory = {
diff --git a/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts b/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts
index cc1223c6c..b832029b5 100644
--- a/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts
@@ -33,6 +33,10 @@ vi.mock("@/lib/auth/audit", () => ({
 vi.mock("@/lib/cache/invalidate", () => ({
   invalidateUserMedications: vi.fn(),
 }));
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  consumeForIntake: vi.fn().mockResolvedValue(undefined),
+  restoreForIntake: vi.fn().mockResolvedValue(undefined),
+}));
 vi.mock("@/lib/rollups/medication-compliance-rollups", () => ({
   recomputeMedicationComplianceForEvent: vi.fn().mockResolvedValue(undefined),
 }));
@@ -567,3 +571,173 @@ describe("PUT — v1.15.18 band re-attribution", () => {
     expect(res.status).toBe(422);
   });
 });
+
+// ────────────────────────────────────────────────────────────────────
+// v1.16.10 — inventory consumption seams on PUT / DELETE
+// ────────────────────────────────────────────────────────────────────
+
+describe("PUT / DELETE — v1.16.10 inventory consumption", () => {
+  beforeEach(() => {
+    vi.mocked(getSession).mockResolvedValue(SESSION_TZ as never);
+    vi.mocked(prisma.medication.findUnique).mockResolvedValue({
+      oneShot: false,
+      active: true,
+    } as never);
+    vi.mocked(prisma.medication.update).mockResolvedValue({} as never);
+    stubTwiceDailyMed();
+  });
+
+  it("an edit into taken consumes on the row (no slot move)", async () => {
+    const { consumeForIntake, restoreForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    vi.mocked(prisma.medicationIntakeEvent.findFirst)
+      // PUT lookup — pending row anchored on the 07:00 slot.
+      .mockResolvedValueOnce({
+        id: "e1",
+        userId: "user-1",
+        medicationId: "m1",
+        scheduledFor: at(7, 0),
+        takenAt: null,
+        skipped: false,
+      } as never)
+      // lifecycle liveIntake probe
+      .mockResolvedValue(null as never);
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValue({
+      id: "e1",
+      scheduledFor: at(7, 0),
+      takenAt: at(7, 5),
+      skipped: false,
+    } as never);
+
+    const res = await PUT(putReq({ takenAt: at(7, 5).toISOString() }), ROUTE_CTX);
+    expect(res.status).toBe(200);
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({
+        userId: "user-1",
+        medicationId: "m1",
+        eventId: "e1",
+      }),
+    );
+    expect(restoreForIntake).not.toHaveBeenCalled();
+  });
+
+  it("a taken → skipped edit restores the row's stamp and never consumes", async () => {
+    const { consumeForIntake, restoreForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    vi.mocked(prisma.medicationIntakeEvent.findFirst)
+      .mockResolvedValueOnce({
+        id: "e1",
+        userId: "user-1",
+        medicationId: "m1",
+        scheduledFor: at(7, 0),
+        takenAt: at(7, 5),
+        skipped: false,
+      } as never)
+      .mockResolvedValue(null as never);
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValue({
+      id: "e1",
+      scheduledFor: at(7, 0),
+      takenAt: null,
+      skipped: true,
+    } as never);
+
+    const res = await PUT(putReq({ skipped: true, takenAt: null }), ROUTE_CTX);
+    expect(res.status).toBe(200);
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: "user-1", eventId: "e1" }),
+    );
+    expect(consumeForIntake).not.toHaveBeenCalled();
+  });
+
+  it("a slot-moving taken edit refunds the old row before tombstoning and consumes the converged row — net one", async () => {
+    const { consumeForIntake, restoreForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    vi.mocked(prisma.medicationIntakeEvent.findFirst)
+      .mockResolvedValueOnce({
+        id: "e1",
+        userId: "user-1",
+        medicationId: "m1",
+        scheduledFor: at(7, 0),
+        takenAt: at(7, 5),
+        skipped: false,
+      } as never)
+      .mockResolvedValue(null as never);
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValue(
+      [] as never,
+    );
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValue(
+      {} as never,
+    );
+    vi.mocked(prisma.medicationIntakeEvent.create).mockResolvedValue({
+      id: "e2",
+      userId: "user-1",
+      medicationId: "m1",
+      scheduledFor: at(19, 0),
+      takenAt: at(19, 5),
+      skipped: false,
+    } as never);
+
+    const res = await PUT(
+      putReq({ takenAt: at(19, 5).toISOString() }),
+      ROUTE_CTX,
+    );
+    expect(res.status).toBe(200);
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ eventId: "e1" }),
+    );
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ eventId: "e2" }),
+    );
+    // The refund runs BEFORE the tombstone write.
+    const restoreOrder = vi.mocked(restoreForIntake).mock
+      .invocationCallOrder[0];
+    const tombstoneOrder = vi.mocked(prisma.medicationIntakeEvent.update)
+      .mock.invocationCallOrder[0];
+    expect(restoreOrder).toBeLessThan(tombstoneOrder);
+  });
+
+  it("DELETE refunds the row's stamp before the tombstone", async () => {
+    const { consumeForIntake, restoreForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    vi.mocked(prisma.medicationIntakeEvent.findUnique).mockResolvedValue({
+      id: "e1",
+      userId: "user-1",
+      medicationId: "m1",
+      scheduledFor: at(7, 0),
+      takenAt: at(7, 5),
+      skipped: false,
+    } as never);
+    vi.mocked(prisma.medicationIntakeEvent.findFirst).mockResolvedValue(
+      null as never,
+    );
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValue(
+      {} as never,
+    );
+
+    const res = await DELETE(
+      new NextRequest("http://localhost/api/medications/m1/intake/e1", {
+        method: "DELETE",
+      }),
+      ROUTE_CTX,
+    );
+    expect(res.status).toBe(200);
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: "user-1", eventId: "e1" }),
+    );
+    expect(consumeForIntake).not.toHaveBeenCalled();
+    const restoreOrder = vi.mocked(restoreForIntake).mock
+      .invocationCallOrder[0];
+    const tombstoneOrder = vi.mocked(prisma.medicationIntakeEvent.update)
+      .mock.invocationCallOrder[0];
+    expect(restoreOrder).toBeLessThan(tombstoneOrder);
+  });
+});
diff --git a/src/app/api/medications/[id]/intake/[eventId]/route.ts b/src/app/api/medications/[id]/intake/[eventId]/route.ts
index 997db221a..c6440447f 100644
--- a/src/app/api/medications/[id]/intake/[eventId]/route.ts
+++ b/src/app/api/medications/[id]/intake/[eventId]/route.ts
@@ -11,6 +11,10 @@ import {
   sanitiseZodIssues,
 } from "@/lib/api-response";
 import { updateIntakeEventSchema } from "@/lib/validations/medication";
+import {
+  consumeForIntake,
+  restoreForIntake,
+} from "@/lib/medications/inventory/consumption";
 import { reconcileOneShotState } from "@/lib/medications/lifecycle";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
 import { recomputeMedicationComplianceForEvent } from "@/lib/rollups/medication-compliance-rollups";
@@ -241,6 +245,26 @@ export const PUT = apiHandler(
           syncVersion: { increment: 1 },
         },
       });
+      // v1.16.10 — inventory follows the post-edit state: a row that is
+      // (now) taken consumes (the stamp keeps an already-consumed row
+      // untouched — the stamp freezes what the original take pulled,
+      // even when `unitsPerDose` changed since); a row edited out of
+      // taken (skip flip, takenAt cleared) refunds its stamp.
+      if (nextTakenAt !== null && !nextSkipped) {
+        await consumeForIntake({
+          client: prisma,
+          userId: user.id,
+          medicationId: id,
+          eventId,
+          intakeAt: nextTakenAt,
+        });
+      } else {
+        await restoreForIntake({
+          client: prisma,
+          userId: user.id,
+          eventId,
+        });
+      }
     } else {
       // The edit moved the dose to a different slot. Tombstone the original
       // row (the iOS "a correction is a tombstone + re-insert" model the
@@ -248,6 +272,15 @@ export const PUT = apiHandler(
       // shared canonical-slot upsert, which converges onto any row already at
       // the target slot (a pending REMINDER row) rather than bare-updating
       // into an occupied slot and risking a P2002 (audit HIGH-4).
+      //
+      // v1.16.10 — refund the source row's consumption stamp BEFORE the
+      // tombstone; the consume on the converged row below nets the move
+      // to exactly one consumption.
+      await restoreForIntake({
+        client: prisma,
+        userId: user.id,
+        eventId,
+      });
       await prisma.medicationIntakeEvent.update({
         where: { id: eventId },
         data: { deletedAt: new Date(), syncVersion: { increment: 1 } },
@@ -271,6 +304,15 @@ export const PUT = apiHandler(
         doseTaken: event.doseTaken,
       });
       updated = applied.row;
+      if (nextTakenAt !== null && !nextSkipped) {
+        await consumeForIntake({
+          client: prisma,
+          userId: user.id,
+          medicationId: id,
+          eventId: applied.row.id,
+          intakeAt: nextTakenAt,
+        });
+      }
     }
 
     await auditLog("medication.intake.update", {
@@ -335,6 +377,14 @@ export const DELETE = apiHandler(
       return apiError("Intake not found", 404);
     }
 
+    // v1.16.10 — a deleted dose record refunds its consumption stamp
+    // (no-op for a never-consumed row; a re-delete finds it cleared).
+    await restoreForIntake({
+      client: prisma,
+      userId: user.id,
+      eventId,
+    });
+
     // v1.7.0 sync — soft-delete instead of a hard `delete`. An intake is
     // an immutable fact, so a "correction" is a tombstone + re-insert
     // (never an in-place edit). Setting `deletedAt` (+ bumping
diff --git a/src/app/api/medications/[id]/intake/__tests__/route.test.ts b/src/app/api/medications/[id]/intake/__tests__/route.test.ts
index a1ddc4662..4f7f52e5a 100644
--- a/src/app/api/medications/[id]/intake/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/intake/__tests__/route.test.ts
@@ -53,8 +53,9 @@ vi.mock("@/lib/idempotency", () => ({
       fn(...args),
 }));
 
-vi.mock("@/lib/medications/inventory/service", () => ({
-  consumeOneDose: vi.fn().mockResolvedValue(null),
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  consumeForIntake: vi.fn().mockResolvedValue(undefined),
+  restoreForIntake: vi.fn().mockResolvedValue(undefined),
 }));
 
 vi.mock("@/lib/medications/route-guards", () => ({
@@ -412,8 +413,8 @@ describe("POST /api/medications/[id]/intake — v1.8.2 reconcile (M2 inventory)"
   });
 
   it("does NOT decrement inventory on a re-post of an already-taken slot (M2)", async () => {
-    const { consumeOneDose } = await import(
-      "@/lib/medications/inventory/service"
+    const { consumeForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
     );
     // Resolver load → scheduled med.
     vi.mocked(prisma.medication.findFirst).mockResolvedValueOnce(
@@ -455,15 +456,15 @@ describe("POST /api/medications/[id]/intake — v1.8.2 reconcile (M2 inventory)"
     expect(res.status).toBe(201);
     // Re-post of an already-taken slot → no pending→taken transition →
     // inventory must NOT be consumed.
-    expect(consumeOneDose).not.toHaveBeenCalled();
+    expect(consumeForIntake).not.toHaveBeenCalled();
     // The row was updated, not duplicated.
     expect(prisma.medicationIntakeEvent.update).toHaveBeenCalledTimes(1);
     expect(prisma.medicationIntakeEvent.create).not.toHaveBeenCalled();
   });
 
   it("DOES decrement inventory on a genuine pending→taken move (M2)", async () => {
-    const { consumeOneDose } = await import(
-      "@/lib/medications/inventory/service"
+    const { consumeForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
     );
     vi.mocked(prisma.medication.findFirst).mockResolvedValueOnce(
       SCHEDULED_MED as never,
@@ -501,7 +502,14 @@ describe("POST /api/medications/[id]/intake — v1.8.2 reconcile (M2 inventory)"
       ROUTE_PARAMS,
     );
     expect(res.status).toBe(201);
-    expect(consumeOneDose).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({
+        userId: "user-1",
+        medicationId: "med-1",
+        eventId: "row-pending",
+      }),
+    );
   });
 
   it("re-finds and updates the slot when the create races a P2002 (C1)", async () => {
diff --git a/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts b/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts
index f733a8821..2a93e23ee 100644
--- a/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts
@@ -53,6 +53,10 @@ vi.mock("@/lib/rollups/medication-compliance-rollups", () => ({
   recomputeMedicationComplianceForDay: vi.fn().mockResolvedValue(undefined),
 }));
 
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  restoreForIntake: vi.fn().mockResolvedValue(undefined),
+}));
+
 vi.mock("@/lib/cache/invalidate", () => ({
   invalidateUserMedications: vi.fn(),
 }));
@@ -241,3 +245,40 @@ describe("POST /api/medications/[id]/intake/bulk-delete — F-1 H-6 rate limit",
     );
   });
 });
+
+describe("POST /api/medications/[id]/intake/bulk-delete — v1.16.10 inventory refund", () => {
+  it("restores each stamped row before the tombstone sweep and ignores unstamped rows", async () => {
+    const { restoreForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    const day1 = new Date(Date.UTC(2026, 4, 27, 8, 0, 0));
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValueOnce([
+      {
+        id: "evt-stamped",
+        scheduledFor: day1,
+        inventoryConsumption: [{ itemId: "item-1", units: 2 }],
+      },
+      { id: "evt-unstamped", scheduledFor: day1, inventoryConsumption: null },
+    ] as never);
+    vi.mocked(prisma.medicationIntakeEvent.updateMany).mockResolvedValueOnce({
+      count: 2,
+    } as never);
+
+    const res = await POST(
+      postWithBody({ eventIds: ["evt-stamped", "evt-unstamped"] }),
+      ROUTE_PARAMS,
+    );
+    expect(res.status).toBe(200);
+
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: "user-1", eventId: "evt-stamped" }),
+    );
+    // The refund runs BEFORE the soft-delete sweep.
+    const restoreOrder = vi.mocked(restoreForIntake).mock
+      .invocationCallOrder[0];
+    const sweepOrder = vi.mocked(prisma.medicationIntakeEvent.updateMany)
+      .mock.invocationCallOrder[0];
+    expect(restoreOrder).toBeLessThan(sweepOrder);
+  });
+});
diff --git a/src/app/api/medications/[id]/intake/bulk-delete/route.ts b/src/app/api/medications/[id]/intake/bulk-delete/route.ts
index 29eb45e76..d6daf54ad 100644
--- a/src/app/api/medications/[id]/intake/bulk-delete/route.ts
+++ b/src/app/api/medications/[id]/intake/bulk-delete/route.ts
@@ -11,6 +11,7 @@ import {
 } from "@/lib/api-response";
 import { checkRateLimit, rateLimitHeaders } from "@/lib/rate-limit";
 import { bulkDeleteIntakeEventsSchema } from "@/lib/validations/medication";
+import { restoreForIntake } from "@/lib/medications/inventory/consumption";
 import { assertMedicationOwnership } from "@/lib/medications/route-guards";
 import {
   dayKeyForScheduledFor,
@@ -106,7 +107,7 @@ export const POST = apiHandler(
         userId: user.id,
         medicationId: id,
       },
-      select: { id: true, scheduledFor: true },
+      select: { id: true, scheduledFor: true, inventoryConsumption: true },
     });
 
     if (targetRows.length === 0) {
@@ -118,6 +119,19 @@ export const POST = apiHandler(
       dayKeysToRefresh.add(dayKeyForScheduledFor(row.scheduledFor, tz));
     }
 
+    // v1.16.10 — refund each stamped row's inventory consumption before
+    // the tombstone sweep. Only stamped rows pay the round trip; the
+    // hook is best-effort and never blocks the delete.
+    for (const row of targetRows) {
+      if (row.inventoryConsumption !== null) {
+        await restoreForIntake({
+          client: prisma,
+          userId: user.id,
+          eventId: row.id,
+        });
+      }
+    }
+
     // v1.15.18 LOW-6 — soft-delete to match the single-event DELETE handler
     // and the iOS tombstone contract: an intake is an immutable fact, so a
     // bulk "delete" sets `deletedAt` (+ bumps `syncVersion`) so the
diff --git a/src/app/api/medications/[id]/intake/route.ts b/src/app/api/medications/[id]/intake/route.ts
index 0fe4beafb..31bad637b 100644
--- a/src/app/api/medications/[id]/intake/route.ts
+++ b/src/app/api/medications/[id]/intake/route.ts
@@ -17,7 +17,10 @@ import {
 import { resolveInjectionSiteForWrite } from "@/lib/medications/injection-site-write";
 import type { InjectionSiteKey } from "@/lib/medications/injection-sites";
 import { withIdempotency } from "@/lib/idempotency";
-import { consumeOneDose } from "@/lib/medications/inventory/service";
+import {
+  consumeForIntake,
+  restoreForIntake,
+} from "@/lib/medications/inventory/consumption";
 import { reconcileOneShotState } from "@/lib/medications/lifecycle";
 import { assertMedicationOwnership } from "@/lib/medications/route-guards";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
@@ -415,35 +418,27 @@ async function postIntake(request: NextRequest, { params }: RouteParams) {
     }
   }
 
-  // v1.4.25 W19b — pen-inventory dose decrement. Only fires for
-  // non-skipped intakes; a skipped event is not a consumption event.
-  // No-op when the medication has no tracked pens (most non-GLP-1
-  // meds). Failures here must never block the intake write, so
-  // errors are swallowed and logged — the intake is the source of
-  // truth, the inventory is an opt-in companion.
-  //
-  // v1.8.2 M2 — gate on an ACTUAL pending→taken transition. An idempotent
-  // re-post of an already-taken slot updates the row in place but must NOT
-  // decrement again, else a repeated iOS sync drifts the GLP-1 pen count
-  // down on every replay. `consumedTransition` is false when the slot was
-  // already taken (or on a no-downgrade no-op).
-  let inventoryOutcome: Awaited<ReturnType<typeof consumeOneDose>> = null;
+  // v1.16.10 — inventory consumption / restore. A taken write consumes
+  // `unitsPerDose` units (the stamp on the event row makes replays and
+  // re-posts exactly-once; `consumedTransition` skips the read for the
+  // no-op echo cases the slot upsert already classified). An explicit
+  // skip can downgrade a previously-taken row (last-write-wins), so it
+  // refunds whatever that row's stamp recorded. Both hooks are
+  // best-effort and never block the intake write.
   if (!skipped && consumedTransition) {
-    try {
-      inventoryOutcome = await consumeOneDose({
-        userId: user.id,
-        medicationId: id,
-        intakeAt: event.takenAt ?? event.scheduledFor,
-      });
-    } catch (err) {
-      annotate({
-        action: { name: "medication.inventory.consume_error" },
-        meta: {
-          medication_id: id,
-          message: err instanceof Error ? err.message : String(err),
-        },
-      });
-    }
+    await consumeForIntake({
+      client: prisma,
+      userId: user.id,
+      medicationId: id,
+      eventId: event.id,
+      intakeAt: event.takenAt ?? event.scheduledFor,
+    });
+  } else if (skipped) {
+    await restoreForIntake({
+      client: prisma,
+      userId: user.id,
+      eventId: event.id,
+    });
   }
 
   await auditLog("medication.intake", {
@@ -453,12 +448,6 @@ async function postIntake(request: NextRequest, { params }: RouteParams) {
       medicationId: id,
       eventId: event.id,
       skipped,
-      ...(inventoryOutcome
-        ? {
-            inventoryItemId: inventoryOutcome.itemId,
-            inventoryChange: inventoryOutcome.change,
-          }
-        : {}),
     },
   });
 
@@ -471,12 +460,6 @@ async function postIntake(request: NextRequest, { params }: RouteParams) {
     meta: {
       medication_id: id,
       skipped,
-      ...(inventoryOutcome
-        ? {
-            inventory_item_id: inventoryOutcome.itemId,
-            inventory_change: inventoryOutcome.change,
-          }
-        : {}),
     },
   });
 
diff --git a/src/app/api/medications/[id]/inventory/[itemId]/__tests__/route.test.ts b/src/app/api/medications/[id]/inventory/[itemId]/__tests__/route.test.ts
index 799378209..37792abf5 100644
--- a/src/app/api/medications/[id]/inventory/[itemId]/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/inventory/[itemId]/__tests__/route.test.ts
@@ -137,8 +137,8 @@ describe("PATCH /api/medications/[id]/inventory/[itemId] — dosesRemaining stoc
       userId: "user-1",
       firstUseAt: null,
       state: "IN_USE",
-      dosesTotal: 4,
-      dosesRemaining: 3,
+      unitsTotal: 4,
+      unitsRemaining: 3,
       printedExpiry: null,
       notes: null,
     } as never);
@@ -154,25 +154,25 @@ describe("PATCH /api/medications/[id]/inventory/[itemId] — dosesRemaining stoc
     const res = await PATCH(patchReq({ dosesRemaining: 1 }), ROUTE_CTX);
     expect(res.status).toBe(200);
     const update = vi.mocked(prisma.medicationInventoryItem.update).mock
-      .calls[0][0] as { data: { dosesRemaining: number } };
-    expect(update.data.dosesRemaining).toBe(1);
+      .calls[0][0] as unknown as { data: { unitsRemaining: number } };
+    expect(update.data.unitsRemaining).toBe(1);
   });
 
   it("derives USED_UP when corrected to zero", async () => {
     const res = await PATCH(patchReq({ dosesRemaining: 0 }), ROUTE_CTX);
     expect(res.status).toBe(200);
     const update = vi.mocked(prisma.medicationInventoryItem.update).mock
-      .calls[0][0] as { data: { dosesRemaining: number; state: string } };
-    expect(update.data.dosesRemaining).toBe(0);
+      .calls[0][0] as unknown as { data: { unitsRemaining: number; state: string } };
+    expect(update.data.unitsRemaining).toBe(0);
     expect(update.data.state).toBe("USED_UP");
   });
 
-  it("clamps a raise above the item's capacity to dosesTotal", async () => {
+  it("clamps a raise above the item's capacity to unitsTotal", async () => {
     const res = await PATCH(patchReq({ dosesRemaining: 99 }), ROUTE_CTX);
     expect(res.status).toBe(200);
     const update = vi.mocked(prisma.medicationInventoryItem.update).mock
-      .calls[0][0] as { data: { dosesRemaining: number } };
-    expect(update.data.dosesRemaining).toBe(4);
+      .calls[0][0] as unknown as { data: { unitsRemaining: number } };
+    expect(update.data.unitsRemaining).toBe(4);
   });
 
   it("rejects a negative correction with 422", async () => {
diff --git a/src/app/api/medications/[id]/inventory/[itemId]/route.ts b/src/app/api/medications/[id]/inventory/[itemId]/route.ts
index 684026b20..d31d2b47e 100644
--- a/src/app/api/medications/[id]/inventory/[itemId]/route.ts
+++ b/src/app/api/medications/[id]/inventory/[itemId]/route.ts
@@ -82,7 +82,7 @@ export const PATCH = apiHandler(
     // commutative — applying them in any order produces the same row.
     let nextFirstUseAt = existing.firstUseAt;
     let nextState = existing.state;
-    let nextDosesRemaining = existing.dosesRemaining;
+    let nextUnitsRemaining = existing.unitsRemaining;
     let nextPrintedExpiry = existing.printedExpiry;
 
     if (markAsFirstUseAt) {
@@ -98,14 +98,15 @@ export const PATCH = apiHandler(
 
     if (dosesRemaining !== undefined) {
       // v1.16.1 — stock correction (Bestand tab adjust / withdraw).
-      // Clamp to the item's capacity; the state-machine re-run below
-      // owns every state consequence (0 ⇒ USED_UP, a raise out of 0
-      // re-evaluates against the expiry clocks).
-      nextDosesRemaining = Math.min(dosesRemaining, existing.dosesTotal);
+      // The wire field counts UNITS. Clamp to the item's capacity; the
+      // state-machine re-run below owns every state consequence (0 ⇒
+      // USED_UP, a raise out of 0 re-evaluates against the expiry
+      // clocks).
+      nextUnitsRemaining = Math.min(dosesRemaining, existing.unitsTotal);
     }
 
     if (markAsUsedUp === true) {
-      nextDosesRemaining = 0;
+      nextUnitsRemaining = 0;
       nextState = "USED_UP";
     }
 
@@ -124,8 +125,8 @@ export const PATCH = apiHandler(
     nextState = computeInventoryState(
       {
         state: nextState,
-        dosesTotal: existing.dosesTotal,
-        dosesRemaining: nextDosesRemaining,
+        unitsTotal: existing.unitsTotal,
+        unitsRemaining: nextUnitsRemaining,
         firstUseAt: nextFirstUseAt,
         printedExpiry: nextPrintedExpiry,
       },
@@ -137,7 +138,7 @@ export const PATCH = apiHandler(
       data: {
         state: nextState,
         firstUseAt: nextFirstUseAt,
-        dosesRemaining: nextDosesRemaining,
+        unitsRemaining: nextUnitsRemaining,
         printedExpiry: nextPrintedExpiry,
         expiresAt: nextExpiresAt,
         notes: notes === undefined ? existing.notes : notes,
@@ -185,7 +186,7 @@ export const DELETE = apiHandler(
         medicationId: id,
         itemId,
         finalState: existing.state,
-        dosesRemaining: existing.dosesRemaining,
+        unitsRemaining: existing.unitsRemaining,
       },
     });
 
diff --git a/src/app/api/medications/[id]/inventory/__tests__/route.test.ts b/src/app/api/medications/[id]/inventory/__tests__/route.test.ts
index 4d23b8c1f..14b1cd9d2 100644
--- a/src/app/api/medications/[id]/inventory/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/inventory/__tests__/route.test.ts
@@ -165,8 +165,9 @@ describe("POST /api/medications/[id]/inventory", () => {
         userId: "user-1",
         medicationId: "med-1",
         state: "ACTIVE",
-        dosesTotal: 4,
-        dosesRemaining: 4,
+        containerType: "OTHER",
+        unitsTotal: 4,
+        unitsRemaining: 4,
         firstUseAt: null,
         printedExpiry: new Date(printed),
         expiresAt: new Date(printed),
@@ -198,8 +199,8 @@ describe("PATCH /api/medications/[id]/inventory/[itemId]", () => {
     userId: "user-1",
     medicationId: "med-1",
     state: "ACTIVE" as const,
-    dosesTotal: 4,
-    dosesRemaining: 4,
+    unitsTotal: 4,
+    unitsRemaining: 4,
     firstUseAt: null,
     printedExpiry: null,
     purchasedAt: null,
@@ -243,12 +244,12 @@ describe("PATCH /api/medications/[id]/inventory/[itemId]", () => {
       ...existingActive,
       state: "IN_USE",
       firstUseAt: new Date("2026-05-01"),
-      dosesRemaining: 2,
+      unitsRemaining: 2,
     } as never);
     vi.mocked(prisma.medicationInventoryItem.update).mockResolvedValue({
       ...existingActive,
       state: "USED_UP",
-      dosesRemaining: 0,
+      unitsRemaining: 0,
     } as never);
 
     const res = await PATCH(
@@ -264,7 +265,7 @@ describe("PATCH /api/medications/[id]/inventory/[itemId]", () => {
       .calls[0][0];
     expect(updateCall.data).toMatchObject({
       state: "USED_UP",
-      dosesRemaining: 0,
+      unitsRemaining: 0,
     });
   });
 
@@ -331,7 +332,7 @@ describe("DELETE /api/medications/[id]/inventory/[itemId]", () => {
       userId: "user-1",
       medicationId: "med-1",
       state: "EXPIRED",
-      dosesRemaining: 2,
+      unitsRemaining: 2,
     } as never);
     vi.mocked(prisma.medicationInventoryItem.delete).mockResolvedValue({
       id: "inv-1",
diff --git a/src/app/api/medications/[id]/inventory/route.ts b/src/app/api/medications/[id]/inventory/route.ts
index 41b3a5ebf..0f4bbb205 100644
--- a/src/app/api/medications/[id]/inventory/route.ts
+++ b/src/app/api/medications/[id]/inventory/route.ts
@@ -90,13 +90,17 @@ export const POST = apiHandler(
       return returnAllZodIssues(parsed.error, 422);
     }
 
-    const { dosesTotal, printedExpiry, purchasedAt, notes } = parsed.data;
+    const { dosesTotal, containerType, printedExpiry, purchasedAt, notes } =
+      parsed.data;
 
     const created = await prisma.medicationInventoryItem.create({
+      // The wire field `dosesTotal` counts UNITS (tablets / ampoules /
+      // puffs) — the v1.16.10 rename to `unitsTotal` happens here.
       data: buildCreateInventoryInput({
         userId: user.id,
         medicationId: id,
-        dosesTotal,
+        unitsTotal: dosesTotal,
+        containerType: containerType ?? "OTHER",
         printedExpiry: printedExpiry ?? null,
         purchasedAt: purchasedAt ?? null,
         notes: notes ?? null,
@@ -109,7 +113,8 @@ export const POST = apiHandler(
       details: {
         medicationId: id,
         itemId: created.id,
-        dosesTotal,
+        unitsTotal: dosesTotal,
+        containerType: created.containerType,
       },
     });
 
diff --git a/src/app/api/medications/[id]/route.ts b/src/app/api/medications/[id]/route.ts
index b7c729399..d8b7b4263 100644
--- a/src/app/api/medications/[id]/route.ts
+++ b/src/app/api/medications/[id]/route.ts
@@ -222,6 +222,7 @@ export const PUT = apiHandler(
       category,
       treatmentClass,
       dosesPerUnit,
+      unitsPerDose,
       deliveryForm,
       trackInjectionSites,
       allowedInjectionSites,
@@ -515,6 +516,9 @@ export const PUT = apiHandler(
       ...(dose !== undefined && { dose }),
       ...(treatmentClass !== undefined && { treatmentClass }),
       ...(dosesPerUnit !== undefined && { dosesPerUnit }),
+      // v1.16.10 — units consumed per dose. Field-by-field; the stamp on
+      // already-taken intake events freezes their recorded consumption.
+      ...(unitsPerDose !== undefined && { unitsPerDose }),
       ...(deliveryForm !== undefined && { deliveryForm }),
       // v1.8.5 — injection-site tracking opt-in + per-medication allowed
       // sites. Field-by-field; `false` / `[]` are valid explicit values
diff --git a/src/app/api/medications/intake/__tests__/route.test.ts b/src/app/api/medications/intake/__tests__/route.test.ts
index d5f824d08..a09280791 100644
--- a/src/app/api/medications/intake/__tests__/route.test.ts
+++ b/src/app/api/medications/intake/__tests__/route.test.ts
@@ -8,6 +8,8 @@ vi.mock("@/lib/db", () => ({
       findUnique: vi.fn(),
       findFirst: vi.fn(),
       update: vi.fn(),
+      // v1.16.10 — the slot-move path re-inserts via the shared upsert.
+      create: vi.fn(),
       // v1.4.39 W-SERVER-FIX — `scope=today` now backfills missing
       // rows for schedules whose window opens today (covers daily
       // meds with `daysOfWeek: null` whose reminder hasn't fired yet).
@@ -18,6 +20,8 @@ vi.mock("@/lib/db", () => ({
       // v1.4.39 W-SERVER-FIX — today's projection reads active meds +
       // their schedules to know what to backfill.
       findMany: vi.fn(),
+      // v1.15.18 — the band resolver loads the medication via findFirst.
+      findFirst: vi.fn(),
     },
     medicationComplianceRollup: {
       findFirst: vi.fn(),
@@ -44,6 +48,11 @@ vi.mock("@/lib/auth/audit", () => ({
   auditLog: vi.fn().mockResolvedValue(undefined),
 }));
 
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  consumeForIntake: vi.fn().mockResolvedValue(undefined),
+  restoreForIntake: vi.fn().mockResolvedValue(undefined),
+}));
+
 vi.mock("@/lib/logging/transports", () => ({ emitIfSampled: vi.fn() }));
 
 vi.mock("@/lib/db-compat", () => ({
@@ -62,6 +71,10 @@ vi.mock("next/headers", () => ({
 import { GET, POST } from "../route";
 import { prisma } from "@/lib/db";
 import { getSession } from "@/lib/auth/session";
+import {
+  consumeForIntake,
+  restoreForIntake,
+} from "@/lib/medications/inventory/consumption";
 import { __resetAllCachesForTests } from "@/lib/cache/server-cache";
 
 const SESSION_OK = {
@@ -366,6 +379,147 @@ describe("POST /api/medications/intake", () => {
       where: { id: "e1" },
       data: { takenAt: null, skipped: true, syncVersion: { increment: 1 } },
     });
+    // v1.16.10 — a row toggled out of taken refunds its consumption
+    // stamp (no-op for a never-consumed row) and never consumes.
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: "user-1", eventId: "e1" }),
+    );
+    expect(consumeForIntake).not.toHaveBeenCalled();
+  });
+
+  // ── v1.16.10 — inventory consumption seams ──────────────────────────
+
+  it("taken (no slot move) consumes inventory exactly once on the toggled row", async () => {
+    vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+    const slot = new Date("2026-05-18T10:00:00.000Z");
+    vi.mocked(prisma.medicationIntakeEvent.findFirst).mockResolvedValue({
+      id: "e1",
+      userId: "user-1",
+      medicationId: "m1",
+      scheduledFor: slot,
+      takenAt: null,
+      skipped: false,
+      injectionSite: null,
+      doseTaken: null,
+      medication: {
+        deliveryForm: "ORAL",
+        trackInjectionSites: false,
+        allowedInjectionSites: [],
+      },
+    } as never);
+    // Band resolver: schedule-less medication → ad-hoc attribution on the
+    // takenAt, which equals the existing anchor → no slot move.
+    vi.mocked(prisma.medication.findFirst).mockResolvedValue({
+      id: "m1",
+      startsOn: null,
+      endsOn: null,
+      oneShot: false,
+      createdAt: new Date("2026-01-01T00:00:00.000Z"),
+      schedules: [],
+      scheduleRevisions: [],
+    } as never);
+    vi.mocked(prisma.$transaction).mockImplementation(async (arg: unknown) =>
+      Array.isArray(arg) ? Promise.all(arg) : (arg as (c: unknown) => unknown)(prisma),
+    );
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValue({
+      id: "e1",
+      takenAt: slot,
+      skipped: false,
+      scheduledFor: slot,
+    } as never);
+    vi.mocked(prisma.medication.update).mockResolvedValue({} as never);
+
+    const res = await POST(
+      req({
+        intakeId: "e1",
+        status: "taken",
+        takenAt: slot.toISOString(),
+      }),
+    );
+    expect(res.status).toBe(200);
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({
+        userId: "user-1",
+        medicationId: "m1",
+        eventId: "e1",
+      }),
+    );
+    expect(restoreForIntake).not.toHaveBeenCalled();
+  });
+
+  it("taken with a slot move restores the old row's stamp before tombstoning and consumes the converged row — net one", async () => {
+    vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+    const oldSlot = new Date("2026-05-18T10:00:00.000Z");
+    const takenAt = new Date("2026-05-18T15:00:00.000Z");
+    vi.mocked(prisma.medicationIntakeEvent.findFirst).mockResolvedValue({
+      id: "e1",
+      userId: "user-1",
+      medicationId: "m1",
+      scheduledFor: oldSlot,
+      takenAt: oldSlot,
+      skipped: false,
+      injectionSite: null,
+      doseTaken: null,
+      medication: {
+        deliveryForm: "ORAL",
+        trackInjectionSites: false,
+        allowedInjectionSites: [],
+      },
+    } as never);
+    // Schedule-less → ad-hoc attribution on the new takenAt → slot moves.
+    vi.mocked(prisma.medication.findFirst).mockResolvedValue({
+      id: "m1",
+      startsOn: null,
+      endsOn: null,
+      oneShot: false,
+      createdAt: new Date("2026-01-01T00:00:00.000Z"),
+      schedules: [],
+      scheduleRevisions: [],
+    } as never);
+    // Tombstone write on e1, then the shared upsert: no row at the target
+    // slot → create the converged row e2.
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValue({
+      id: "e1",
+    } as never);
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValue(
+      [] as never,
+    );
+    vi.mocked(prisma.medicationIntakeEvent.create).mockResolvedValue({
+      id: "e2",
+      takenAt,
+      skipped: false,
+      idempotencyKey: null,
+      scheduledFor: takenAt,
+      source: "WEB",
+      createdAt: takenAt,
+    } as never);
+    vi.mocked(prisma.medication.update).mockResolvedValue({} as never);
+
+    const res = await POST(
+      req({
+        intakeId: "e1",
+        status: "taken",
+        takenAt: takenAt.toISOString(),
+      }),
+    );
+    expect(res.status).toBe(200);
+    // Net one: refund the source row, consume the converged row.
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ eventId: "e1" }),
+    );
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ eventId: "e2" }),
+    );
+    // The refund runs BEFORE the tombstone write on the source row.
+    const restoreOrder = vi.mocked(restoreForIntake).mock
+      .invocationCallOrder[0];
+    const tombstoneOrder = vi.mocked(prisma.medicationIntakeEvent.update)
+      .mock.invocationCallOrder[0];
+    expect(restoreOrder).toBeLessThan(tombstoneOrder);
   });
 });
 
diff --git a/src/app/api/medications/intake/bulk/__tests__/route.test.ts b/src/app/api/medications/intake/bulk/__tests__/route.test.ts
index 92d669497..61c827638 100644
--- a/src/app/api/medications/intake/bulk/__tests__/route.test.ts
+++ b/src/app/api/medications/intake/bulk/__tests__/route.test.ts
@@ -42,6 +42,10 @@ vi.mock("@/lib/idempotency", () => ({
 vi.mock("@/lib/cache/invalidate", () => ({
   invalidateUserMedications: vi.fn(),
 }));
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  consumeForIntake: vi.fn().mockResolvedValue(undefined),
+  restoreForIntake: vi.fn().mockResolvedValue(undefined),
+}));
 vi.mock("@/lib/rollups/medication-compliance-rollups", () => ({
   recomputeMedicationComplianceForDay: vi.fn().mockResolvedValue(undefined),
   dayKeyForScheduledFor: vi.fn().mockReturnValue("2026-01-01"),
@@ -64,6 +68,10 @@ import { prisma } from "@/lib/db";
 import { getSession } from "@/lib/auth/session";
 import { checkRateLimit } from "@/lib/rate-limit";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
+import {
+  consumeForIntake,
+  restoreForIntake,
+} from "@/lib/medications/inventory/consumption";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
@@ -805,3 +813,180 @@ describe("POST /api/medications/intake/bulk — v1.15.20 band attribution", () =
     );
   });
 });
+
+// ────────────────────────────────────────────────────────────────────
+// v1.16.10 — inventory consumption seams
+// ────────────────────────────────────────────────────────────────────
+
+describe("POST /api/medications/intake/bulk — v1.16.10 inventory consumption", () => {
+  const SCHEDULED_MED = {
+    id: "med-1",
+    startsOn: null,
+    endsOn: null,
+    oneShot: false,
+    createdAt: new Date("2026-01-01T00:00:00Z"),
+    schedules: [
+      {
+        id: "s1",
+        windowStart: "07:00",
+        windowEnd: "07:00",
+        daysOfWeek: null,
+        timesOfDay: ["07:00", "19:00"],
+        reminderGraceMinutes: null,
+        rrule: null,
+        rollingIntervalDays: null,
+        scheduleType: "SCHEDULED",
+        cyclicOnWeeks: null,
+        cyclicOffWeeks: null,
+        doseWindows: null,
+      },
+    ],
+  };
+
+  beforeEach(() => {
+    vi.useFakeTimers({ toFake: ["Date"] });
+    vi.setSystemTime(new Date("2026-06-15T18:00:00.000Z"));
+    vi.mocked(prisma.medication.findMany).mockResolvedValue([
+      { id: "med-1" },
+    ] as never);
+    vi.mocked(prisma.medication.findFirst).mockResolvedValue(
+      SCHEDULED_MED as never,
+    );
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("consumes exactly once per taken entry, on the landed row id", async () => {
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValueOnce([
+      {
+        id: "row-pending",
+        takenAt: null,
+        skipped: false,
+        idempotencyKey: null,
+        scheduledFor: new Date("2026-06-15T05:00:00Z"),
+        source: "REMINDER",
+        createdAt: new Date("2026-06-15T00:00:00Z"),
+      },
+    ] as never);
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValueOnce({
+      id: "row-pending",
+    } as never);
+
+    const res = await POST(
+      postReq({
+        entries: [
+          {
+            medicationId: "med-1",
+            scheduledFor: "2026-06-15T05:00:30.000Z",
+            takenAt: "2026-06-15T05:02:00.000Z",
+          },
+        ],
+      }),
+    );
+    expect(res.status).toBe(200);
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({
+        userId: "user-1",
+        medicationId: "med-1",
+        eventId: "row-pending",
+      }),
+    );
+    expect(restoreForIntake).not.toHaveBeenCalled();
+  });
+
+  it("C2 — a pending echo onto an already-taken slot never reaches consume", async () => {
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValueOnce([
+      {
+        id: "row-taken",
+        takenAt: new Date("2026-06-15T05:01:00Z"),
+        skipped: false,
+        idempotencyKey: null,
+        scheduledFor: new Date("2026-06-15T05:00:00Z"),
+        source: "WEB",
+        createdAt: new Date("2026-06-15T05:01:00Z"),
+      },
+    ] as never);
+
+    const res = await POST(
+      postReq({
+        entries: [
+          {
+            medicationId: "med-1",
+            scheduledFor: "2026-06-15T05:00:30.000Z",
+            // no takenAt, skipped defaults false → pending echo
+          },
+        ],
+      }),
+    );
+    expect(res.status).toBe(200);
+    expect(consumeForIntake).not.toHaveBeenCalled();
+    expect(restoreForIntake).not.toHaveBeenCalled();
+  });
+
+  it("an explicit skip entry restores the slot row's stamp instead of consuming", async () => {
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValueOnce([
+      {
+        id: "row-taken",
+        takenAt: new Date("2026-06-15T05:01:00Z"),
+        skipped: false,
+        idempotencyKey: null,
+        scheduledFor: new Date("2026-06-15T05:00:00Z"),
+        source: "WEB",
+        createdAt: new Date("2026-06-15T05:01:00Z"),
+      },
+    ] as never);
+    vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValueOnce({
+      id: "row-taken",
+    } as never);
+
+    const res = await POST(
+      postReq({
+        entries: [
+          {
+            medicationId: "med-1",
+            scheduledFor: "2026-06-15T05:00:30.000Z",
+            skipped: true,
+          },
+        ],
+      }),
+    );
+    expect(res.status).toBe(200);
+    expect(consumeForIntake).not.toHaveBeenCalled();
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: "user-1", eventId: "row-taken" }),
+    );
+  });
+
+  it("an idempotency-key replay (duplicate) never consumes again", async () => {
+    // An off-window take (00:20 local night, no scheduledFor) resolves
+    // ad-hoc → the resolver-null branch runs its replay pre-check and
+    // classifies the re-submission as a duplicate.
+    vi.setSystemTime(new Date("2026-06-15T00:30:00.000Z"));
+    vi.mocked(prisma.medicationIntakeEvent.findUnique).mockResolvedValueOnce({
+      id: "row-existing",
+    } as never);
+
+    const res = await POST(
+      postReq({
+        entries: [
+          {
+            medicationId: "med-1",
+            takenAt: "2026-06-15T00:20:00.000Z",
+            idempotencyKey: "ios-replay-1",
+          },
+        ],
+      }),
+    );
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as {
+      data: { duplicates: number; entries: Array<{ status: string }> };
+    };
+    expect(body.data.duplicates).toBe(1);
+    expect(body.data.entries[0].status).toBe("duplicate");
+    expect(consumeForIntake).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/app/api/medications/intake/bulk/route.ts b/src/app/api/medications/intake/bulk/route.ts
index 5a1440f62..aa231b9ea 100644
--- a/src/app/api/medications/intake/bulk/route.ts
+++ b/src/app/api/medications/intake/bulk/route.ts
@@ -58,6 +58,10 @@ import {
   resolveSlotInstantForWrite,
 } from "@/lib/medications/scheduling/slot-upsert";
 import { resolveInjectionSiteForWrite } from "@/lib/medications/injection-site-write";
+import {
+  consumeForIntake,
+  restoreForIntake,
+} from "@/lib/medications/inventory/consumption";
 import {
   boundedTakenAtSchema,
   injectionSiteEnum,
@@ -407,7 +411,8 @@ async function postBulk(request: NextRequest): Promise<Response> {
         if (applied.noDowngradeNoOp) {
           // C2 — pending echo onto an already-actioned slot. Report it as a
           // duplicate so the iOS cursor advances WITHOUT downgrading the
-          // recorded dose.
+          // recorded dose. A pending echo is never a taken write, so it
+          // must never reach the inventory consume below.
           duplicates += 1;
           results.push({ index: i, status: "duplicate", id: applied.row.id });
         } else if (applied.outcome === "updated") {
@@ -417,6 +422,25 @@ async function postBulk(request: NextRequest): Promise<Response> {
           inserted += 1;
           results.push({ index: i, status: "inserted", id: applied.row.id });
         }
+        // v1.16.10 — inventory: a taken write consumes (the stamp on the
+        // row makes a replayed sync batch exactly-once), an explicit skip
+        // refunds a previously-taken row's stamp. Pending echoes carry
+        // neither flag and never touch stock.
+        if (!applied.noDowngradeNoOp && isExplicitTaken) {
+          await consumeForIntake({
+            client: prisma,
+            userId: user.id,
+            medicationId: entry.medicationId,
+            eventId: applied.row.id,
+            intakeAt: entry.takenAt as Date,
+          });
+        } else if (!applied.noDowngradeNoOp && isExplicitSkip) {
+          await restoreForIntake({
+            client: prisma,
+            userId: user.id,
+            eventId: applied.row.id,
+          });
+        }
       } else {
         // Resolver-null: PRN / off-slot / future-slot-guarded. Before the
         // standalone insert, two guards keep the slot from forking into a
@@ -485,6 +509,22 @@ async function postBulk(request: NextRequest): Promise<Response> {
             inserted += 1;
             results.push({ index: i, status: "inserted", id: applied.row.id });
           }
+          // v1.16.10 — same inventory rule as the canonical-slot branch.
+          if (!applied.noDowngradeNoOp && isExplicitTaken) {
+            await consumeForIntake({
+              client: prisma,
+              userId: user.id,
+              medicationId: entry.medicationId,
+              eventId: applied.row.id,
+              intakeAt: entry.takenAt as Date,
+            });
+          } else if (!applied.noDowngradeNoOp && isExplicitSkip) {
+            await restoreForIntake({
+              client: prisma,
+              userId: user.id,
+              eventId: applied.row.id,
+            });
+          }
         } else {
           // Genuinely standalone. Anchor the row on the intake instant —
           // the documented ad-hoc contract (`scheduledFor = takenAt`) — so
@@ -515,6 +555,18 @@ async function postBulk(request: NextRequest): Promise<Response> {
           });
           inserted += 1;
           results.push({ index: i, status: "inserted", id: row.id });
+          // v1.16.10 — a fresh standalone taken row consumes inventory
+          // units (a fresh skip / pending row has nothing to consume or
+          // refund).
+          if (isExplicitTaken) {
+            await consumeForIntake({
+              client: prisma,
+              userId: user.id,
+              medicationId: entry.medicationId,
+              eventId: row.id,
+              intakeAt: entry.takenAt as Date,
+            });
+          }
         }
       }
       const dayKey = dayKeyForScheduledFor(
diff --git a/src/app/api/medications/intake/route.ts b/src/app/api/medications/intake/route.ts
index cbc3461a5..2ffc077f3 100644
--- a/src/app/api/medications/intake/route.ts
+++ b/src/app/api/medications/intake/route.ts
@@ -42,6 +42,10 @@ import {
   resolveSlotForWriteByBand,
 } from "@/lib/medications/scheduling/slot-upsert";
 import { resolveInjectionSiteForWrite } from "@/lib/medications/injection-site-write";
+import {
+  consumeForIntake,
+  restoreForIntake,
+} from "@/lib/medications/inventory/consumption";
 import {
   injectionSiteEnum,
   type InjectionSiteValue,
@@ -540,11 +544,32 @@ export const POST = apiHandler(async (request: NextRequest) => {
           data: { snoozedUntil: null },
         }),
       ]);
+      // v1.16.10 — the toggle recorded a take; consume inventory units.
+      // The stamp on the row makes a re-toggle of an already-taken slot
+      // a no-op, so the count only moves on the genuine pending→taken
+      // (or skipped→taken) transition.
+      await consumeForIntake({
+        client: prisma,
+        userId: user.id,
+        medicationId: existing.medicationId,
+        eventId: intakeId,
+        intakeAt: resolvedTakenAt,
+      });
     } else {
       // The take re-attributed to a different slot. Tombstone the source row
       // and route the dose through the shared canonical-slot upsert, which
       // converges onto any row already at the target slot rather than
       // bare-updating into an occupied slot (P2002-safe).
+      //
+      // v1.16.10 — refund the source row's consumption stamp BEFORE the
+      // tombstone, then consume on the converged row below: a slot move
+      // is a re-binding of one real dose, so the stock nets exactly one
+      // consumption.
+      await restoreForIntake({
+        client: prisma,
+        userId: user.id,
+        eventId: intakeId,
+      });
       await prisma.medicationIntakeEvent.update({
         where: { id: intakeId },
         data: { deletedAt: new Date(), syncVersion: { increment: 1 } },
@@ -574,6 +599,15 @@ export const POST = apiHandler(async (request: NextRequest) => {
         where: { id: existing.medicationId },
         data: { snoozedUntil: null },
       });
+      // v1.16.10 — consume on the converged row (the old row's stamp
+      // was refunded above, so the move nets one consumption).
+      await consumeForIntake({
+        client: prisma,
+        userId: user.id,
+        medicationId: existing.medicationId,
+        eventId: applied.row.id,
+        intakeAt: resolvedTakenAt,
+      });
     }
   } else if (status === "skipped") {
     updated = await prisma.medicationIntakeEvent.update({
@@ -581,6 +615,13 @@ export const POST = apiHandler(async (request: NextRequest) => {
       // v1.7.0 sync — bump the reconciliation counter on the skip toggle.
       data: { takenAt: null, skipped: true, syncVersion: { increment: 1 } },
     });
+    // v1.16.10 — the row stopped being taken; refund whatever its
+    // consumption stamp recorded (no-op for a never-consumed row).
+    await restoreForIntake({
+      client: prisma,
+      userId: user.id,
+      eventId: intakeId,
+    });
   } else {
     // snoozed: snoozedUntil lives on the Medication row.
     const until = snoozedUntil ?? new Date(Date.now() + 30 * 60_000); // default +30min
diff --git a/src/app/api/medications/route.ts b/src/app/api/medications/route.ts
index 2da559eaa..f8da7dde9 100644
--- a/src/app/api/medications/route.ts
+++ b/src/app/api/medications/route.ts
@@ -245,6 +245,7 @@ export const POST = apiHandler(async (request: NextRequest) => {
     category,
     treatmentClass,
     dosesPerUnit,
+    unitsPerDose,
     deliveryForm,
     trackInjectionSites,
     allowedInjectionSites,
@@ -312,6 +313,8 @@ export const POST = apiHandler(async (request: NextRequest) => {
       // wire schema; Prisma fills the default GENERIC when omitted.
       ...(treatmentClass !== undefined && { treatmentClass }),
       ...(dosesPerUnit !== undefined && { dosesPerUnit }),
+      // v1.16.10 — units consumed per dose; Prisma defaults to 1 when omitted.
+      ...(unitsPerDose !== undefined && { unitsPerDose }),
       // v1.6.0 — route of administration; Prisma defaults to ORAL when omitted.
       ...(deliveryForm !== undefined && { deliveryForm }),
       // v1.8.5 — injection-site tracking opt-in + per-medication allowed
diff --git a/src/app/api/telegram/webhook/__tests__/route.test.ts b/src/app/api/telegram/webhook/__tests__/route.test.ts
index ce8c8f72d..69b863a78 100644
--- a/src/app/api/telegram/webhook/__tests__/route.test.ts
+++ b/src/app/api/telegram/webhook/__tests__/route.test.ts
@@ -55,6 +55,11 @@ vi.mock("@/lib/logging/context", () => ({
   })),
 }));
 
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  consumeForIntake: vi.fn().mockResolvedValue(undefined),
+  restoreForIntake: vi.fn().mockResolvedValue(undefined),
+}));
+
 vi.mock("@/lib/cache/invalidate", () => ({
   invalidateUserMedications: vi.fn(),
 }));
@@ -257,6 +262,15 @@ describe("Telegram webhook — callback dispatch", () => {
     });
     // Intake write + snooze reset commit atomically.
     expect(prisma.$transaction).toHaveBeenCalledTimes(1);
+    // v1.16.10 — the confirmed take consumes inventory units (after the
+    // intake transaction committed, on the created row).
+    const { consumeForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    expect(consumeForIntake).toHaveBeenCalledTimes(1);
+    expect(consumeForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: "user-1", medicationId: "med-1" }),
+    );
 
     expect(answerTelegramCallbackQuery).toHaveBeenCalledTimes(1);
     expect(deleteMessage).toHaveBeenCalledWith(
@@ -329,6 +343,13 @@ describe("Telegram webhook — callback dispatch", () => {
     expect(snoozedUntil.getMinutes()).toBe(59);
     // Skip row + rest-of-day snooze commit atomically.
     expect(prisma.$transaction).toHaveBeenCalledTimes(1);
+    // v1.16.10 — an explicit skip refunds a previously-consumed stamp
+    // (no-op for a never-consumed row) and never consumes.
+    const { consumeForIntake, restoreForIntake } = await import(
+      "@/lib/medications/inventory/consumption"
+    );
+    expect(consumeForIntake).not.toHaveBeenCalled();
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
   });
 
   it("'ack:<medId>' answers the callback without creating an intake event", async () => {
diff --git a/src/app/api/telegram/webhook/route.ts b/src/app/api/telegram/webhook/route.ts
index 6a95195a6..e5e5620ef 100644
--- a/src/app/api/telegram/webhook/route.ts
+++ b/src/app/api/telegram/webhook/route.ts
@@ -20,6 +20,10 @@ import {
   resolveSlotForWriteByBand,
 } from "@/lib/medications/scheduling/slot-upsert";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
+import {
+  consumeForIntake,
+  restoreForIntake,
+} from "@/lib/medications/inventory/consumption";
 import { localHmAsUtc } from "@/lib/tz/local-day";
 import { wallClockInTz } from "@/lib/tz/wall-clock";
 import { DEFAULT_TIMEZONE } from "@/lib/tz/format";
@@ -268,8 +272,9 @@ async function markMedicationTaken(
     // an aborted Postgres transaction, so the rare create race rolls the
     // whole write back instead of converging in place — Telegram
     // redelivers the non-200 update and the retry finds the raced row.
-    scheduledFor = await prisma.$transaction(async (tx) => {
+    const written = await prisma.$transaction(async (tx) => {
       let slotScheduledFor: Date;
+      let eventId: string;
       if (canonicalSlot) {
         const applied = await applyCanonicalSlotWrite({
           client: tx,
@@ -285,6 +290,7 @@ async function markMedicationTaken(
           attributionSource: "AUTO",
         });
         slotScheduledFor = applied.row.scheduledFor;
+        eventId = applied.row.id;
       } else {
         // Ad-hoc / PRN — standalone row under the documented contract
         // (`scheduledFor = takenAt`).
@@ -300,12 +306,25 @@ async function markMedicationTaken(
           },
         });
         slotScheduledFor = created.scheduledFor;
+        eventId = created.id;
       }
       await tx.medication.update({
         where: { id: medication.id },
         data: { snoozedUntil: null },
       });
-      return slotScheduledFor;
+      return { slotScheduledFor, eventId };
+    });
+    scheduledFor = written.slotScheduledFor;
+    // v1.16.10 — the button confirmed a take; consume inventory units.
+    // Runs after the intake transaction committed (the dose record must
+    // never hinge on the stock write); the stamp keeps a Telegram
+    // redelivery exactly-once.
+    await consumeForIntake({
+      client: prisma,
+      userId,
+      medicationId: medication.id,
+      eventId: written.eventId,
+      intakeAt: takenAt,
     });
     // The confirmation must reflect on the next read (today feed, card
     // pill, compliance) rather than wait out the cache TTL.
@@ -494,8 +513,9 @@ async function handleCallback(update: TelegramUpdate) {
       // re-reminded for a recorded skip or silenced without one. Same
       // P2002 trade-off as the take path — the rare create race rolls
       // back and Telegram's redelivery converges on the raced row.
-      skippedScheduledFor = await prisma.$transaction(async (tx) => {
+      const writtenSkip = await prisma.$transaction(async (tx) => {
         let slotScheduledFor: Date;
+        let eventId: string;
         if (canonicalSlot) {
           const applied = await applyCanonicalSlotWrite({
             client: tx,
@@ -510,6 +530,7 @@ async function handleCallback(update: TelegramUpdate) {
             createSource: "REMINDER",
           });
           slotScheduledFor = applied.row.scheduledFor;
+          eventId = applied.row.id;
         } else {
           const created = await tx.medicationIntakeEvent.create({
             data: {
@@ -523,12 +544,22 @@ async function handleCallback(update: TelegramUpdate) {
             },
           });
           slotScheduledFor = created.scheduledFor;
+          eventId = created.id;
         }
         await tx.medication.update({
           where: { id: medication.id },
           data: { snoozedUntil: endOfDay },
         });
-        return slotScheduledFor;
+        return { slotScheduledFor, eventId };
+      });
+      skippedScheduledFor = writtenSkip.slotScheduledFor;
+      // v1.16.10 — an explicit skip can downgrade a previously-taken
+      // slot row (last-write-wins); refund whatever its consumption
+      // stamp recorded. No-op for a never-consumed row.
+      await restoreForIntake({
+        client: prisma,
+        userId: user.id,
+        eventId: writtenSkip.eventId,
       });
       invalidateUserMedications(user.id, { evict: true });
     }
diff --git a/src/components/medications/__tests__/add-inventory-dialog.test.tsx b/src/components/medications/__tests__/add-inventory-dialog.test.tsx
new file mode 100644
index 000000000..35e39d1c0
--- /dev/null
+++ b/src/components/medications/__tests__/add-inventory-dialog.test.tsx
@@ -0,0 +1,173 @@
+/**
+ * v1.16.10 — `<AddInventoryDialog>` register-flow coverage.
+ *
+ * Pins the multi-unit quantity input: the segmented Dosen | Einheiten
+ * control only surfaces when a dose spans more than one unit, the live
+ * conversion line renders next to the quantity, the POST always carries
+ * UNITS, and the container-type select defaults from the delivery form.
+ *
+ * Project convention is SSR-only component tests (`renderToStaticMarkup`,
+ * no `@testing-library/react`) plus source-string structural assertions
+ * for the interactive plumbing an SSR mount can't exercise.
+ */
+import { describe, expect, it, vi } from "vitest";
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+import { renderToStaticMarkup } from "react-dom/server";
+
+import { I18nProvider } from "@/lib/i18n/context";
+
+// The Radix Dialog / Select portal at runtime, so their bodies never
+// materialise in static markup. Collapse the primitives to plain
+// wrappers (same trick as the LogInjectionSiteDialog suite).
+vi.mock("@/components/ui/dialog", () => {
+  const Pass = ({ children }: { children?: React.ReactNode }) => (
+    <div>{children}</div>
+  );
+  return {
+    Dialog: ({ children }: { children?: React.ReactNode }) => (
+      <div data-slot="mock-dialog">{children}</div>
+    ),
+    DialogContent: Pass,
+    DialogDescription: Pass,
+    DialogFooter: Pass,
+    DialogHeader: Pass,
+    DialogTitle: Pass,
+  };
+});
+
+vi.mock("@/components/ui/select", () => {
+  const Pass = ({ children }: { children?: React.ReactNode }) => (
+    <div>{children}</div>
+  );
+  return {
+    Select: ({
+      value,
+      children,
+    }: {
+      value: string;
+      children?: React.ReactNode;
+    }) => <div data-mock-select-value={value}>{children}</div>,
+    SelectContent: Pass,
+    SelectItem: ({ children }: { children?: React.ReactNode }) => (
+      <div data-slot="mock-select-item">{children}</div>
+    ),
+    SelectTrigger: Pass,
+    SelectValue: () => null,
+  };
+});
+
+vi.mock("@tanstack/react-query", () => ({
+  useQuery: vi.fn(() => ({ data: undefined, isLoading: false })),
+  useQueryClient: () => ({
+    invalidateQueries: vi.fn().mockResolvedValue(undefined),
+  }),
+}));
+
+vi.mock("sonner", () => ({
+  toast: { success: vi.fn(), error: vi.fn() },
+}));
+
+const { AddInventoryDialog } = await import(
+  "../sections/inventory-section"
+);
+
+function render(node: React.ReactNode, locale: "en" | "de" = "de"): string {
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale={locale}>{node}</I18nProvider>,
+  );
+}
+
+const src = readFileSync(
+  resolve(__dirname, "../sections/inventory-section.tsx"),
+  "utf8",
+);
+
+describe("<AddInventoryDialog>", () => {
+  it("surfaces the Dosen | Einheiten segmented control only for multi-unit doses", () => {
+    const multi = render(
+      <AddInventoryDialog
+        medicationId="med-1"
+        defaultUnitsTotal={28}
+        unitsPerDose={4}
+        initialContainerType="BLISTER"
+        onClose={() => {}}
+      />,
+    );
+    expect(multi).toContain('data-slot="inventory-quantity-mode"');
+    expect(multi).toContain(">Dosen<");
+    expect(multi).toContain(">Einheiten<");
+
+    const single = render(
+      <AddInventoryDialog
+        medicationId="med-1"
+        defaultUnitsTotal={28}
+        unitsPerDose={1}
+        initialContainerType="BLISTER"
+        onClose={() => {}}
+      />,
+    );
+    expect(single).not.toContain('data-slot="inventory-quantity-mode"');
+  });
+
+  it("renders the live conversion next to the prefilled quantity (units mode → dose equivalent)", () => {
+    // Prefill 28 units at 4 units per dose → "≈ 7 Dosen".
+    const html = render(
+      <AddInventoryDialog
+        medicationId="med-1"
+        defaultUnitsTotal={28}
+        unitsPerDose={4}
+        initialContainerType="BLISTER"
+        onClose={() => {}}
+      />,
+    );
+    expect(html).toContain('data-slot="inventory-quantity-conversion"');
+    expect(html).toContain("≈ 7 Dosen");
+  });
+
+  it("defaults the container type from the caller (delivery-form mapping upstream)", () => {
+    const html = render(
+      <AddInventoryDialog
+        medicationId="med-1"
+        defaultUnitsTotal={null}
+        unitsPerDose={1}
+        initialContainerType="PEN"
+        onClose={() => {}}
+      />,
+    );
+    expect(html).toContain('data-mock-select-value="PEN"');
+    // All six container kinds are offered.
+    for (const label of [
+      "Pen",
+      "Ampulle",
+      "Tablettenpackung",
+      "Inhalator",
+      "Flasche",
+      "Sonstiges",
+    ]) {
+      expect(html).toContain(label);
+    }
+  });
+
+  it("always submits UNITS: dose-mode input multiplies by unitsPerDose before the POST", () => {
+    // Interactive mode-switching is out of SSR reach; the structural
+    // contract lives in the source: the submitted value is the converted
+    // unit count, and the wire field stays `dosesTotal`.
+    expect(src).toMatch(
+      /const units =\s*\n?\s*effectiveMode === "doses" \? parsed \* unitsPerDose : parsed;/,
+    );
+    expect(src).toMatch(/dosesTotal: units,/);
+    expect(src).toMatch(/containerType,/);
+  });
+
+  it("bounds the quantity to 1000 units (dose mode scales the max down)", () => {
+    expect(src).toContain("units >= 1 && units <= 1000");
+    expect(src).toContain('Math.floor(1000 / unitsPerDose)');
+  });
+
+  it("maps the delivery form onto the register default (PEN for INJECTION, BLISTER for ORAL, OTHER otherwise)", () => {
+    expect(src).toMatch(
+      /if \(deliveryForm === "INJECTION"\) return "PEN";\s*\n\s*if \(deliveryForm === "ORAL"\) return "BLISTER";\s*\n\s*return "OTHER";/,
+    );
+  });
+});
diff --git a/src/components/medications/__tests__/supply-runway.test.ts b/src/components/medications/__tests__/supply-runway.test.ts
index bb08eb09b..727cb9f6e 100644
--- a/src/components/medications/__tests__/supply-runway.test.ts
+++ b/src/components/medications/__tests__/supply-runway.test.ts
@@ -106,3 +106,27 @@ describe("estimateRunwayDays", () => {
     ).toBe(28);
   });
 });
+
+describe("estimateRunwayDays — v1.16.10 multi-unit doses", () => {
+  it("runs off the dose-derived count: floor(units / unitsPerDose) before dividing by daily consumption", () => {
+    // 9 units at 2 units per dose → floor(9 / 2) = 4 doses; a daily
+    // single-dose schedule then reads 4 days of runway. The call sites
+    // (Übersicht supply row, Bestand summary) derive the dose count this
+    // way before handing it to the estimator.
+    const unitsRemaining = 9;
+    const unitsPerDose = 2;
+    const dosesRemaining = Math.floor(unitsRemaining / unitsPerDose);
+    expect(
+      estimateRunwayDays(dosesRemaining, [schedule({ timesOfDay: ["08:00"] })]),
+    ).toBe(4);
+  });
+
+  it("a partial dose's worth of units never counts as a day", () => {
+    // 1 unit at 2 units per dose is not a dose → no runway.
+    expect(
+      estimateRunwayDays(Math.floor(1 / 2), [
+        schedule({ timesOfDay: ["08:00"] }),
+      ]),
+    ).toBeNull();
+  });
+});
diff --git a/src/components/medications/detail/MedicationDetailTabs.tsx b/src/components/medications/detail/MedicationDetailTabs.tsx
index 25f90fb8b..fc6738656 100644
--- a/src/components/medications/detail/MedicationDetailTabs.tsx
+++ b/src/components/medications/detail/MedicationDetailTabs.tsx
@@ -125,6 +125,8 @@ export interface MedicationDetailSnapshot {
   treatmentClass?: string;
   deliveryForm?: string;
   dosesPerUnit?: number | null;
+  /** v1.16.10 — inventory units one dose consumes (default 1). */
+  unitsPerDose?: number | null;
   trackInjectionSites?: boolean;
   allowedInjectionSites?: string[];
   active: boolean;
@@ -179,6 +181,7 @@ function snapshotToWizardPayload(
     treatmentClass: med.treatmentClass,
     deliveryForm: med.deliveryForm,
     dosesPerUnit: med.dosesPerUnit ?? null,
+    unitsPerDose: med.unitsPerDose ?? 1,
     trackInjectionSites: med.trackInjectionSites ?? false,
     allowedInjectionSites: med.allowedInjectionSites ?? [],
     notificationsEnabled: med.notificationsEnabled,
@@ -314,8 +317,8 @@ export function MedicationDetailTabs({
         return await apiGet<{
           items: Array<{
             state: "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
-            dosesTotal: number;
-            dosesRemaining: number;
+            unitsTotal: number;
+            unitsRemaining: number;
           }>;
         } | null>(`/api/medications/${id}/inventory`);
       } catch {
@@ -328,11 +331,18 @@ export function MedicationDetailTabs({
 
   const inventoryItems = Array.isArray(inventory?.items) ? inventory.items : [];
   const liveItems = inventoryItems.filter((i) => i.state !== "USED_UP");
-  const dosesRemaining = liveItems.reduce(
-    (sum, i) => sum + i.dosesRemaining,
+  // v1.16.10 — items count UNITS; the supply readout and the runway are
+  // dose-derived (floor over the pooled units — consumption spills
+  // across containers, so the pool is the honest dose count). The raw
+  // unit tally renders as secondary text when a dose spans > 1 unit.
+  const perDose = Math.max(1, medication.unitsPerDose ?? 1);
+  const unitsRemaining = liveItems.reduce(
+    (sum, i) => sum + i.unitsRemaining,
     0,
   );
-  const dosesTotal = liveItems.reduce((sum, i) => sum + i.dosesTotal, 0);
+  const unitsTotal = liveItems.reduce((sum, i) => sum + i.unitsTotal, 0);
+  const dosesRemaining = Math.floor(unitsRemaining / perDose);
+  const dosesTotal = Math.floor(unitsTotal / perDose);
   const runwayDays = estimateRunwayDays(dosesRemaining, medication.schedules);
 
   return (
@@ -422,6 +432,16 @@ export function MedicationDetailTabs({
                         remaining: dosesRemaining,
                         total: dosesTotal,
                       })}
+                      {perDose > 1 && (
+                        <span className="text-muted-foreground">
+                          {" ("}
+                          {t("medications.detail.bestand.unitsDetail", {
+                            remaining: unitsRemaining,
+                            total: unitsTotal,
+                          })}
+                          {")"}
+                        </span>
+                      )}
                       {runwayDays !== null && (
                         <span className="text-muted-foreground">
                           {" · "}
@@ -562,6 +582,8 @@ export function MedicationDetailTabs({
           <InventorySection
             medicationId={id}
             dosesPerUnit={medication.dosesPerUnit}
+            unitsPerDose={medication.unitsPerDose}
+            deliveryForm={medication.deliveryForm}
           />
         </TabsContent>
 
diff --git a/src/components/medications/sections/inventory-section.tsx b/src/components/medications/sections/inventory-section.tsx
index 195763ce1..93e062d5d 100644
--- a/src/components/medications/sections/inventory-section.tsx
+++ b/src/components/medications/sections/inventory-section.tsx
@@ -6,20 +6,29 @@
  * v1.16.1 — the tab grows its write affordances:
  *
  *   - REGISTER: a "+" flow (header button + the empty-state CTA) that
- *     records a new pen / pack via `POST /api/medications/[id]/inventory`
- *     — quantity in doses/units, optional printed expiry. The quantity
- *     prefills from the medication's `dosesPerUnit` when configured.
+ *     records a new pack / container via
+ *     `POST /api/medications/[id]/inventory` — quantity in units,
+ *     optional printed expiry. The quantity prefills from the
+ *     medication's `dosesPerUnit` when configured.
  *   - CORRECT: a per-item adjust flow (`PATCH …/inventory/[itemId]` with
  *     `dosesRemaining`) for stock corrections and manual withdrawals —
  *     the count is set absolutely, clamped server-side to the item's
  *     capacity, and the canonical state machine derives the next state
  *     (0 ⇒ used up).
  *
+ * v1.16.10 — items count UNITS (tablets / ampoules / puffs);
+ * `Medication.unitsPerDose` maps units to doses. Every dose-facing
+ * readout divides by it (floor), with the raw unit count as secondary
+ * text when the factor is > 1. The register flow gains a container-type
+ * select (pen / ampoule / tablet pack / …, defaulted from the delivery
+ * form) and, for multi-unit doses, a segmented Dosen | Einheiten
+ * quantity input with live conversion — the wire always carries units.
+ *
  * Reads stay on `GET /api/medications/[id]/inventory` (the same
- * per-item list the pen/vial CRUD route serves): a calm summary — the
+ * per-item list the inventory CRUD route serves): a calm summary — the
  * doses remaining across every non-terminal item — plus a per-item list
- * with its state badge. Shown for ALL medications (pill packs count
- * too); the richer pen math is implicit in the per-item doses figures.
+ * with its container type and state badge. Shown for ALL medications
+ * (pill packs count too).
  */
 
 import { useState, type FormEvent } from "react";
@@ -39,6 +48,13 @@ import {
 } from "@/components/ui/dialog";
 import { EmptyState } from "@/components/ui/empty-state";
 import { Input } from "@/components/ui/input";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
 import { SettingsGroup } from "@/components/medications/settings-group";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
@@ -46,11 +62,22 @@ import { apiGet, apiPatch, apiPost } from "@/lib/api/api-fetch";
 
 type InventoryState = "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
 
+const CONTAINER_TYPES = [
+  "PEN",
+  "AMPOULE",
+  "BLISTER",
+  "INHALER",
+  "BOTTLE",
+  "OTHER",
+] as const;
+type ContainerType = (typeof CONTAINER_TYPES)[number];
+
 interface InventoryItem {
   id: string;
   state: InventoryState;
-  dosesTotal: number;
-  dosesRemaining: number;
+  containerType: ContainerType;
+  unitsTotal: number;
+  unitsRemaining: number;
 }
 
 interface InventoryResponse {
@@ -65,18 +92,33 @@ const STATE_BADGE: Record<InventoryState, "secondary" | "outline" | "destructive
   USED_UP: "outline",
 };
 
+/** Default container kind for the register flow, from the delivery form. */
+function defaultContainerType(deliveryForm: string | undefined): ContainerType {
+  if (deliveryForm === "INJECTION") return "PEN";
+  if (deliveryForm === "ORAL") return "BLISTER";
+  return "OTHER";
+}
+
 export function InventorySection({
   medicationId,
   dosesPerUnit,
+  unitsPerDose,
+  deliveryForm,
 }: {
   medicationId: string;
   /** Prefills the register flow's quantity when the medication tracks it. */
   dosesPerUnit?: number | null;
+  /** Units one dose consumes; dose-derived readouts divide by it. */
+  unitsPerDose?: number | null;
+  /** Defaults the register flow's container type. */
+  deliveryForm?: string;
 }) {
   const { t } = useTranslations();
   const [addOpen, setAddOpen] = useState(false);
   const [adjustItem, setAdjustItem] = useState<InventoryItem | null>(null);
 
+  const perDose = Math.max(1, unitsPerDose ?? 1);
+
   const { data, isLoading } = useQuery<InventoryResponse>({
     queryKey: queryKeys.medicationInventory(medicationId),
     queryFn: async () => {
@@ -102,17 +144,22 @@ export function InventorySection({
   }
 
   const items = Array.isArray(data?.items) ? data.items : [];
-  // Active supply: doses left across every non-terminal (not used-up) item.
+  // Active supply: units left across every non-terminal (not used-up) item.
   const live = items.filter((i) => i.state !== "USED_UP");
-  const remaining = live.reduce((sum, i) => sum + i.dosesRemaining, 0);
-  const total = live.reduce((sum, i) => sum + i.dosesTotal, 0);
+  const remainingUnits = live.reduce((sum, i) => sum + i.unitsRemaining, 0);
+  const totalUnits = live.reduce((sum, i) => sum + i.unitsTotal, 0);
+  // Dose-derived headline (floor — a partial dose is not a dose).
+  const remaining = Math.floor(remainingUnits / perDose);
+  const total = Math.floor(totalUnits / perDose);
 
   const dialogs = (
     <>
       {addOpen && (
         <AddInventoryDialog
           medicationId={medicationId}
-          defaultDosesTotal={dosesPerUnit ?? null}
+          defaultUnitsTotal={dosesPerUnit ?? null}
+          unitsPerDose={perDose}
+          initialContainerType={defaultContainerType(deliveryForm)}
           onClose={() => setAddOpen(false)}
         />
       )}
@@ -155,6 +202,14 @@ export function InventorySection({
         <div className="flex items-center justify-between gap-3 py-3">
           <p className="text-foreground text-sm font-medium">
             {t("medications.detail.bestand.summary", { remaining, total })}
+            {perDose > 1 && (
+              <span className="text-muted-foreground block text-xs font-normal">
+                {t("medications.detail.bestand.unitsDetail", {
+                  remaining: remainingUnits,
+                  total: totalUnits,
+                })}
+              </span>
+            )}
           </p>
           <Button
             variant="outline"
@@ -180,10 +235,26 @@ export function InventorySection({
             data-slot="inventory-item-row"
           >
             <span className="text-foreground text-sm">
-              {t("medications.detail.bestand.doses", {
-                remaining: item.dosesRemaining,
-                total: item.dosesTotal,
-              })}
+              <span className="block">
+                {t(
+                  `medications.detail.bestand.containerType.${item.containerType}`,
+                )}
+              </span>
+              <span className="text-muted-foreground block text-xs">
+                {t("medications.detail.bestand.doses", {
+                  remaining: Math.floor(item.unitsRemaining / perDose),
+                  total: Math.floor(item.unitsTotal / perDose),
+                })}
+                {perDose > 1 && (
+                  <>
+                    {" · "}
+                    {t("medications.detail.bestand.unitsDetail", {
+                      remaining: item.unitsRemaining,
+                      total: item.unitsTotal,
+                    })}
+                  </>
+                )}
+              </span>
             </span>
             <span className="flex shrink-0 items-center gap-1">
               <Badge variant={STATE_BADGE[item.state]} className="text-xs">
@@ -209,32 +280,47 @@ export function InventorySection({
 }
 
 /**
- * Register a new pen / pack. Two fields (quantity + optional printed
- * expiry) → Dialog per ui-guidelines §2.3. The quantity prefills from
- * the medication's `dosesPerUnit` so the common case is one tap.
+ * Register a new pack / container. Quantity (units), container type and
+ * optional printed expiry → Dialog per ui-guidelines §2.3. The quantity
+ * prefills from the medication's `dosesPerUnit` so the common case is
+ * one tap. For multi-unit doses (`unitsPerDose > 1`) a segmented
+ * Dosen | Einheiten control converts live — the POST always carries
+ * units.
  */
-function AddInventoryDialog({
+export function AddInventoryDialog({
   medicationId,
-  defaultDosesTotal,
+  defaultUnitsTotal,
+  unitsPerDose,
+  initialContainerType,
   onClose,
 }: {
   medicationId: string;
-  defaultDosesTotal: number | null;
+  defaultUnitsTotal: number | null;
+  unitsPerDose: number;
+  initialContainerType: ContainerType;
   onClose: () => void;
 }) {
   const { t } = useTranslations();
   const queryClient = useQueryClient();
-  const [dosesTotal, setDosesTotal] = useState(
-    defaultDosesTotal && defaultDosesTotal >= 1 && defaultDosesTotal <= 100
-      ? String(defaultDosesTotal)
+  const [quantity, setQuantity] = useState(
+    defaultUnitsTotal && defaultUnitsTotal >= 1 && defaultUnitsTotal <= 1000
+      ? String(defaultUnitsTotal)
       : "",
   );
+  // The unit the typed quantity is read in. Only surfaced when a dose
+  // spans several units; the stored value is ALWAYS units.
+  const [quantityMode, setQuantityMode] = useState<"units" | "doses">("units");
+  const [containerType, setContainerType] =
+    useState<ContainerType>(initialContainerType);
   const [expiry, setExpiry] = useState("");
   const [busy, setBusy] = useState(false);
 
-  const parsed = Number(dosesTotal);
+  const parsed = Number(quantity);
+  const effectiveMode = unitsPerDose > 1 ? quantityMode : "units";
+  const units =
+    effectiveMode === "doses" ? parsed * unitsPerDose : parsed;
   const quantityValid =
-    Number.isInteger(parsed) && parsed >= 1 && parsed <= 100;
+    Number.isInteger(parsed) && parsed >= 1 && units >= 1 && units <= 1000;
 
   async function submit(e: FormEvent) {
     e.preventDefault();
@@ -242,7 +328,9 @@ function AddInventoryDialog({
     setBusy(true);
     try {
       await apiPost(`/api/medications/${medicationId}/inventory`, {
-        dosesTotal: parsed,
+        // Wire field name is `dosesTotal`; it carries UNITS.
+        dosesTotal: units,
+        containerType,
         printedExpiry: expiry
           ? new Date(`${expiry}T00:00:00`).toISOString()
           : null,
@@ -269,6 +357,33 @@ function AddInventoryDialog({
           </DialogDescription>
         </DialogHeader>
         <form onSubmit={submit} className="space-y-4">
+          <div className="space-y-2">
+            <label
+              htmlFor="inventory-add-container-type"
+              className="text-sm font-medium"
+            >
+              {t("medications.detail.bestand.containerTypeLabel")}
+            </label>
+            <Select
+              value={containerType}
+              onValueChange={(v) => setContainerType(v as ContainerType)}
+            >
+              <SelectTrigger
+                id="inventory-add-container-type"
+                className="w-full"
+                data-slot="inventory-container-type"
+              >
+                <SelectValue />
+              </SelectTrigger>
+              <SelectContent>
+                {CONTAINER_TYPES.map((ct) => (
+                  <SelectItem key={ct} value={ct}>
+                    {t(`medications.detail.bestand.containerType.${ct}`)}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+          </div>
           <div className="space-y-2">
             <label
               htmlFor="inventory-add-quantity"
@@ -276,19 +391,60 @@ function AddInventoryDialog({
             >
               {t("medications.detail.bestand.addQuantityLabel")}
             </label>
+            {unitsPerDose > 1 && (
+              <div
+                className="border-border/60 inline-flex rounded-md border p-0.5"
+                role="group"
+                aria-label={t("medications.detail.bestand.addQuantityLabel")}
+                data-slot="inventory-quantity-mode"
+              >
+                <Button
+                  type="button"
+                  size="sm"
+                  variant={quantityMode === "doses" ? "secondary" : "ghost"}
+                  aria-pressed={quantityMode === "doses"}
+                  className="h-7 px-2 text-xs"
+                  onClick={() => setQuantityMode("doses")}
+                >
+                  {t("medications.detail.bestand.quantityModeDoses")}
+                </Button>
+                <Button
+                  type="button"
+                  size="sm"
+                  variant={quantityMode === "units" ? "secondary" : "ghost"}
+                  aria-pressed={quantityMode === "units"}
+                  className="h-7 px-2 text-xs"
+                  onClick={() => setQuantityMode("units")}
+                >
+                  {t("medications.detail.bestand.quantityModeUnits")}
+                </Button>
+              </div>
+            )}
             <Input
               id="inventory-add-quantity"
               type="number"
               inputMode="numeric"
               min={1}
-              max={100}
+              max={effectiveMode === "doses" ? Math.floor(1000 / unitsPerDose) : 1000}
               step={1}
               required
               autoComplete="off"
-              value={dosesTotal}
-              onChange={(e) => setDosesTotal(e.target.value)}
+              value={quantity}
+              onChange={(e) => setQuantity(e.target.value)}
               aria-describedby="inventory-add-quantity-helper"
             />
+            {unitsPerDose > 1 && Number.isInteger(parsed) && parsed >= 1 && (
+              <p
+                className="text-muted-foreground text-xs"
+                data-slot="inventory-quantity-conversion"
+              >
+                {effectiveMode === "doses"
+                  ? t("medications.detail.bestand.quantityInUnits", { units })
+                  : t("medications.detail.bestand.quantityInDoses", {
+                      doses: Math.floor(parsed / unitsPerDose),
+                    })}
+              </p>
+            )}
             <p
               id="inventory-add-quantity-helper"
               className="text-muted-foreground text-xs"
@@ -336,7 +492,7 @@ function AddInventoryDialog({
 }
 
 /**
- * Stock correction for one item: sets the remaining-dose count
+ * Stock correction for one item: sets the remaining-unit count
  * absolutely (covers both "I miscounted" and a manual withdrawal). The
  * server clamps to the item's capacity and re-derives the state; 0
  * marks the item used up.
@@ -352,12 +508,12 @@ function AdjustInventoryDialog({
 }) {
   const { t } = useTranslations();
   const queryClient = useQueryClient();
-  const [value, setValue] = useState(String(item.dosesRemaining));
+  const [value, setValue] = useState(String(item.unitsRemaining));
   const [busy, setBusy] = useState(false);
 
   const parsed = Number(value);
   const valid =
-    Number.isInteger(parsed) && parsed >= 0 && parsed <= item.dosesTotal;
+    Number.isInteger(parsed) && parsed >= 0 && parsed <= item.unitsTotal;
 
   async function submit(e: FormEvent) {
     e.preventDefault();
@@ -365,6 +521,7 @@ function AdjustInventoryDialog({
     setBusy(true);
     try {
       await apiPatch(`/api/medications/${medicationId}/inventory/${item.id}`, {
+        // Wire field name is `dosesRemaining`; it carries UNITS.
         dosesRemaining: parsed,
       });
       await queryClient.invalidateQueries({
@@ -403,7 +560,7 @@ function AdjustInventoryDialog({
               type="number"
               inputMode="numeric"
               min={0}
-              max={item.dosesTotal}
+              max={item.unitsTotal}
               step={1}
               required
               autoComplete="off"
@@ -416,7 +573,7 @@ function AdjustInventoryDialog({
               className="text-muted-foreground text-xs"
             >
               {t("medications.detail.bestand.adjustHelper", {
-                total: item.dosesTotal,
+                total: item.unitsTotal,
               })}
             </p>
           </div>
diff --git a/src/components/medications/wizard/__tests__/wizard-payload.test.ts b/src/components/medications/wizard/__tests__/wizard-payload.test.ts
index 5d41d10cc..481649cff 100644
--- a/src/components/medications/wizard/__tests__/wizard-payload.test.ts
+++ b/src/components/medications/wizard/__tests__/wizard-payload.test.ts
@@ -383,6 +383,50 @@ describe("buildCreateBody", () => {
     expect(body.schedules[0].windowEnd).toBe("09:00");
   });
 
+  it("carries unitsPerDose onto the body and round-trips it on edit-hydrate (v1.16.10)", () => {
+    const p: WizardPayload = {
+      ...withCadence("daily"),
+      treatmentRow: "bloodPressure",
+      timesOfDay: ["08:00"],
+      startsOn: new Date(Date.UTC(2026, 4, 28)),
+      endsOn: null,
+      unitsPerDose: "2",
+    };
+    expect(buildCreateBody(p).unitsPerDose).toBe(2);
+
+    // The default "1" still ships (an edit back to 1 must reach the server).
+    expect(buildCreateBody({ ...p, unitsPerDose: "1" }).unitsPerDose).toBe(1);
+    // An empty field omits it (server default applies).
+    expect(buildCreateBody({ ...p, unitsPerDose: "" }).unitsPerDose).toBeUndefined();
+
+    const hydrated = hydrateWizardPayload({
+      id: "m1",
+      name: "Foo",
+      dose: "5 mg",
+      category: "BLOOD_PRESSURE",
+      unitsPerDose: 2,
+      notificationsEnabled: true,
+      startsOn: null,
+      endsOn: null,
+      oneShot: false,
+      schedules: [],
+    });
+    expect(hydrated.unitsPerDose).toBe("2");
+    // Absent on the snapshot → the default 1.
+    const hydratedDefault = hydrateWizardPayload({
+      id: "m1",
+      name: "Foo",
+      dose: "5 mg",
+      category: "BLOOD_PRESSURE",
+      notificationsEnabled: true,
+      startsOn: null,
+      endsOn: null,
+      oneShot: false,
+      schedules: [],
+    });
+    expect(hydratedDefault.unitsPerDose).toBe("1");
+  });
+
   it("emits DIABETES category for the diabetes row", () => {
     const p: WizardPayload = {
       ...withCadence("daily"),
diff --git a/src/components/medications/wizard/steps/Step3Dose.tsx b/src/components/medications/wizard/steps/Step3Dose.tsx
index 8a1593abd..c58cb8ff0 100644
--- a/src/components/medications/wizard/steps/Step3Dose.tsx
+++ b/src/components/medications/wizard/steps/Step3Dose.tsx
@@ -147,13 +147,14 @@ export function Step3Dose({ payload, applyPartial }: StepProps) {
             value={payload.dosesPerUnit}
             onChange={(e) =>
               applyPartial({
-                dosesPerUnit: e.target.value.replace(/[^0-9]/g, "").slice(0, 3),
+                // v1.16.10 — the cap rose to 1000, so four digits.
+                dosesPerUnit: e.target.value.replace(/[^0-9]/g, "").slice(0, 4),
               })
             }
             placeholder={t(
               "medications.wizard.steps.step3.dosesPerUnitPlaceholder",
             )}
-            maxLength={3}
+            maxLength={4}
             autoComplete="off"
           />
           <p className="text-muted-foreground text-xs">
@@ -162,6 +163,33 @@ export function Step3Dose({ payload, applyPartial }: StepProps) {
         </div>
       </div>
 
+      {/* v1.16.10 — units consumed per dose. The inventory counts units
+          (tablets / ampoules); a multi-unit dose (2 × 2 mg for 4 mg)
+          decrements several per take and every dose-level readout
+          divides by this factor. */}
+      <div className="space-y-2">
+        <Label htmlFor="wizard-units-per-dose" className="text-sm">
+          {t("medications.wizard.steps.step3.unitsPerDoseLabel")}
+        </Label>
+        <Input
+          id="wizard-units-per-dose"
+          type="text"
+          inputMode="numeric"
+          value={payload.unitsPerDose}
+          onChange={(e) =>
+            applyPartial({
+              unitsPerDose: e.target.value.replace(/[^0-9]/g, "").slice(0, 3),
+            })
+          }
+          placeholder="1"
+          maxLength={3}
+          autoComplete="off"
+        />
+        <p className="text-muted-foreground text-xs">
+          {t("medications.wizard.steps.step3.unitsPerDoseHint")}
+        </p>
+      </div>
+
       {/* v1.8.5 — injection-site tracking opt-in + allowed-sites editor.
           Shown only for an INJECTION delivery form. Default off; enabling
           it surfaces the post-dose site prompt and the rotation
diff --git a/src/components/medications/wizard/wizard-payload.ts b/src/components/medications/wizard/wizard-payload.ts
index c9f3bf8a5..fff9cd3d2 100644
--- a/src/components/medications/wizard/wizard-payload.ts
+++ b/src/components/medications/wizard/wizard-payload.ts
@@ -219,6 +219,11 @@ export interface WizardPayload {
    * inventory tracking off (maps to `undefined` / NULL on the wire).
    */
   dosesPerUnit: string;
+  /**
+   * v1.16.10 — inventory units one dose consumes (2 × 2 mg tablets for
+   * a 4 mg dose). Empty string / "1" both map to the server default 1.
+   */
+  unitsPerDose: string;
   /**
    * v1.8.5 — per-medication injection-site tracking opt-in. Only
    * surfaced in Step 3 when `deliveryForm === "INJECTION"`. Default
@@ -283,6 +288,7 @@ export function emptyWizardPayload(): WizardPayload {
     treatmentRow: null,
     deliveryForm: "ORAL",
     dosesPerUnit: "",
+    unitsPerDose: "1",
     trackInjectionSites: false,
     allowedInjectionSites: [],
     mode: draft.mode,
@@ -528,6 +534,8 @@ export interface CreateMedicationBody {
   deliveryForm: MedicationDeliveryForm;
   /** v1.6.0 — doses per pen / vial. Omitted when inventory is off. */
   dosesPerUnit?: number;
+  /** v1.16.10 — inventory units per dose. Omitted at the default 1. */
+  unitsPerDose?: number;
   /** v1.8.5 — injection-site tracking opt-in. Omitted for non-injections. */
   trackInjectionSites?: boolean;
   /** v1.8.5 — per-medication allowed sites. Omitted when tracking is off. */
@@ -673,6 +681,7 @@ export function buildCreateBody(
     : committed.schedules;
 
   const parsedDosesPerUnit = Number.parseInt(committed.dosesPerUnit, 10);
+  const parsedUnitsPerDose = Number.parseInt(committed.unitsPerDose, 10);
   const body: CreateMedicationBody = {
     name: committed.name.trim(),
     dose,
@@ -683,6 +692,12 @@ export function buildCreateBody(
       parsedDosesPerUnit >= 1 && {
         dosesPerUnit: parsedDosesPerUnit,
       }),
+    // v1.16.10 — always sent when valid (an edit back to 1 must reach
+    // the server; the create default matches the schema default).
+    ...(Number.isFinite(parsedUnitsPerDose) &&
+      parsedUnitsPerDose >= 1 && {
+        unitsPerDose: parsedUnitsPerDose,
+      }),
     // v1.8.5 — injection-site tracking is only meaningful for an
     // INJECTION delivery form. Always send the boolean for an injection
     // (so edits can deactivate it); send the allowed list only when
@@ -903,6 +918,8 @@ export interface MedicationPayload {
   deliveryForm?: string;
   /** v1.6.0 — doses per pen / vial. NULL = inventory tracking off. */
   dosesPerUnit?: number | null;
+  /** v1.16.10 — inventory units per dose (default 1). */
+  unitsPerDose?: number | null;
   /** v1.8.5 — injection-site tracking opt-in. */
   trackInjectionSites?: boolean;
   /** v1.8.5 — per-medication allowed / preferred injection sites. */
@@ -1014,6 +1031,10 @@ export function hydrateWizardPayload(initial: MedicationPayload): WizardPayload
       typeof initial.dosesPerUnit === "number" && initial.dosesPerUnit >= 1
         ? String(initial.dosesPerUnit)
         : "",
+    unitsPerDose:
+      typeof initial.unitsPerDose === "number" && initial.unitsPerDose >= 1
+        ? String(initial.unitsPerDose)
+        : "1",
     trackInjectionSites: initial.trackInjectionSites ?? false,
     allowedInjectionSites: (initial.allowedInjectionSites ??
       []) as InjectionSiteKey[],
diff --git a/src/lib/ai/coach/__tests__/glp1-snapshot.test.ts b/src/lib/ai/coach/__tests__/glp1-snapshot.test.ts
index a15dfd158..62542b13b 100644
--- a/src/lib/ai/coach/__tests__/glp1-snapshot.test.ts
+++ b/src/lib/ai/coach/__tests__/glp1-snapshot.test.ts
@@ -30,7 +30,8 @@ function fakeMedication(overrides: Partial<Record<string, unknown>> = {}) {
         note: null,
       },
     ],
-    inventoryEvents: [],
+    unitsPerDose: 1,
+    inventoryItems: [],
     intakeEvents: [],
     ...overrides,
   };
@@ -134,4 +135,25 @@ describe("buildGlp1SnapshotBlock", () => {
     expect(out?.medications[0].genericName).toBe("Semaglutide");
     expect(out?.medications[0].currentDose?.unit).toBe("mg");
   });
+
+  it("derives pen inventory from the per-item entities (v1.16.10)", async () => {
+    prismaMock.medication.findMany.mockResolvedValue([
+      fakeMedication({
+        unitsPerDose: 2,
+        inventoryItems: [
+          { state: "IN_USE", unitsTotal: 4, unitsRemaining: 3 },
+          { state: "ACTIVE", unitsTotal: 4, unitsRemaining: 4 },
+          { state: "USED_UP", unitsTotal: 4, unitsRemaining: 0 },
+          { state: "EXPIRED", unitsTotal: 4, unitsRemaining: 4 },
+        ],
+      }),
+    ]);
+    const out = await buildGlp1SnapshotBlock("user-1");
+    // 2 usable containers; 7 pooled units / 2 units per dose = 3 doses.
+    expect(out?.medications[0].penInventory).toEqual({
+      pensRemaining: 2,
+      dosesRemaining: 3,
+      weeksOfSupplyApprox: 3,
+    });
+  });
 });
diff --git a/src/lib/ai/coach/glp1-snapshot.ts b/src/lib/ai/coach/glp1-snapshot.ts
index 917995eae..c48221731 100644
--- a/src/lib/ai/coach/glp1-snapshot.ts
+++ b/src/lib/ai/coach/glp1-snapshot.ts
@@ -266,7 +266,9 @@ export async function buildGlp1SnapshotBlock(
     include: {
       schedules: true,
       doseChanges: { orderBy: { effectiveFrom: "asc" } },
-      inventoryEvents: { orderBy: { occurredAt: "asc" } },
+      // v1.16.10 — pen inventory reads the per-item entities (the rows
+      // the intake consumption hook moves), not the legacy event ledger.
+      inventoryItems: { orderBy: { createdAt: "asc" } },
       intakeEvents: {
         where: { takenAt: { not: null } },
         orderBy: { takenAt: "desc" },
@@ -368,16 +370,29 @@ export async function buildGlp1SnapshotBlock(
 
     const nextInjection = predictNextInjection(schedule, lastInjection, now);
 
-    // Inventory math: running sum of all inventory events for this med.
-    // Convert to "weeks of supply" via dosesPerUnit + the cadence so the
-    // Coach can answer "how long until my next refill?".
+    // Inventory math over the per-item entities (v1.16.10 — the same
+    // rows the Bestand tab and the consumption hook move; the legacy
+    // event ledger no longer receives writes). `pensRemaining` counts
+    // usable containers; `dosesRemaining` pools the units and divides
+    // by `unitsPerDose` so the Coach can answer "how long until my
+    // next refill?".
     let dosesRemaining: number | null = null;
     let pensRemaining: number | null = null;
     let weeksOfSupplyApprox: number | null = null;
-    if (med.inventoryEvents.length > 0 && med.dosesPerUnit) {
-      const units = med.inventoryEvents.reduce((sum, ev) => sum + ev.delta, 0);
-      pensRemaining = Math.max(0, units);
-      dosesRemaining = pensRemaining * med.dosesPerUnit;
+    if (med.inventoryItems.length > 0) {
+      const usable = med.inventoryItems.filter(
+        (item) =>
+          (item.state === "ACTIVE" || item.state === "IN_USE") &&
+          item.unitsRemaining > 0,
+      );
+      const unitsRemaining = usable.reduce(
+        (sum, item) => sum + item.unitsRemaining,
+        0,
+      );
+      pensRemaining = usable.length;
+      dosesRemaining = Math.floor(
+        unitsRemaining / Math.max(1, med.unitsPerDose),
+      );
       const dosesPerWeek =
         schedule?.cadence === "weekly"
           ? 1
diff --git a/src/lib/medications/__tests__/intake-slot-dedup-inventory.test.ts b/src/lib/medications/__tests__/intake-slot-dedup-inventory.test.ts
new file mode 100644
index 000000000..704bee41c
--- /dev/null
+++ b/src/lib/medications/__tests__/intake-slot-dedup-inventory.test.ts
@@ -0,0 +1,171 @@
+/**
+ * v1.16.10 — inventory refunds in the intake-slot dedup pass.
+ *
+ * Collapsing a duplicate slot soft-deletes the loser rows. A loser that
+ * carries a consumption stamp is a REAL taken row whose units left the
+ * stock — tombstoning it without a refund would strand those units
+ * forever (the row is no longer reachable through any user-facing
+ * restore path). The dedup therefore refunds every stamped loser before
+ * the tombstone; unstamped losers (pending / skipped / pre-stamp rows)
+ * never consumed and are swept without a refund round-trip. The winner
+ * keeps its own stamp untouched.
+ */
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    user: { findUnique: vi.fn() },
+    medication: { findMany: vi.fn() },
+    medicationIntakeEvent: {
+      findFirst: vi.fn(),
+      findMany: vi.fn(),
+      updateMany: vi.fn(),
+      update: vi.fn(),
+    },
+  },
+}));
+
+vi.mock("@/lib/jobs/boss-instance", () => ({ getGlobalBoss: vi.fn() }));
+vi.mock("@/lib/logging/context", () => ({ annotate: vi.fn() }));
+vi.mock("@/lib/rollups/medication-compliance-rollups", () => ({
+  recomputeMedicationComplianceForEvent: vi.fn().mockResolvedValue(undefined),
+}));
+vi.mock("@/lib/cache/invalidate", () => ({
+  invalidateUserMedications: vi.fn(),
+}));
+vi.mock("@/lib/medications/inventory/consumption", () => ({
+  restoreForIntake: vi.fn().mockResolvedValue(undefined),
+}));
+
+import { dedupeUserIntakeSlots } from "../intake-slot-dedup";
+import { restoreForIntake } from "@/lib/medications/inventory/consumption";
+import { prisma } from "@/lib/db";
+
+const TZ = "Europe/Berlin";
+
+const SCHEDULE = {
+  id: "s1",
+  windowStart: "07:00",
+  windowEnd: "07:00",
+  daysOfWeek: null,
+  timesOfDay: ["07:00", "19:00"],
+  reminderGraceMinutes: null,
+  rrule: null,
+  rollingIntervalDays: null,
+  scheduleType: "SCHEDULED",
+  cyclicOnWeeks: null,
+  cyclicOffWeeks: null,
+};
+
+const MED = {
+  id: "med-1",
+  userId: "u1",
+  startsOn: null,
+  endsOn: null,
+  oneShot: false,
+  createdAt: new Date("2026-01-01T00:00:00Z"),
+  schedules: [SCHEDULE],
+};
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  vi.mocked(prisma.user.findUnique).mockResolvedValue({
+    timezone: TZ,
+  } as never);
+  vi.mocked(prisma.medication.findMany).mockResolvedValue([MED] as never);
+  vi.mocked(prisma.medicationIntakeEvent.findFirst).mockResolvedValue(
+    null as never,
+  );
+  vi.mocked(prisma.medicationIntakeEvent.updateMany).mockResolvedValue({
+    count: 1,
+  } as never);
+  vi.mocked(prisma.medicationIntakeEvent.update).mockResolvedValue(
+    {} as never,
+  );
+});
+
+describe("dedupeUserIntakeSlots — inventory refunds (v1.16.10)", () => {
+  it("refunds a stamped loser before tombstoning; the winner keeps its stamp", async () => {
+    // 07:00 CEST = 05:00Z. Two TAKEN rows for the same dose — the iOS
+    // drift duplicate (+30 s) beside the server row. The fresher row
+    // (higher syncVersion) wins; the stamped loser must be refunded.
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValue([
+      {
+        id: "r-loser",
+        medicationId: "med-1",
+        scheduledFor: new Date("2026-06-15T05:00:00.000Z"),
+        takenAt: new Date("2026-06-15T05:01:00.000Z"),
+        skipped: false,
+        syncVersion: 0,
+        createdAt: new Date("2026-06-15T05:01:00Z"),
+        attributionSource: "AUTO",
+        source: "WEB",
+        inventoryConsumption: [{ itemId: "item-1", units: 2 }],
+      },
+      {
+        id: "r-winner",
+        medicationId: "med-1",
+        scheduledFor: new Date("2026-06-15T05:00:30.000Z"),
+        takenAt: new Date("2026-06-15T05:01:30.000Z"),
+        skipped: false,
+        syncVersion: 3,
+        createdAt: new Date("2026-06-15T05:01:30Z"),
+        attributionSource: "AUTO",
+        source: "API",
+        inventoryConsumption: [{ itemId: "item-1", units: 2 }],
+      },
+    ] as never);
+
+    const summary = await dedupeUserIntakeSlots("u1");
+    expect(summary.slotsCollapsed).toBe(1);
+    expect(summary.rowsSoftDeleted).toBe(1);
+
+    // Only the LOSER is refunded — the winner keeps its stamp.
+    expect(restoreForIntake).toHaveBeenCalledTimes(1);
+    expect(restoreForIntake).toHaveBeenCalledWith(
+      expect.objectContaining({ userId: "u1", eventId: "r-loser" }),
+    );
+
+    // The refund runs before the loser tombstone sweep.
+    const restoreOrder = vi.mocked(restoreForIntake).mock
+      .invocationCallOrder[0];
+    const sweepOrder = vi.mocked(prisma.medicationIntakeEvent.updateMany)
+      .mock.invocationCallOrder[0];
+    expect(restoreOrder).toBeLessThan(sweepOrder);
+  });
+
+  it("ignores unstamped losers (a pending sibling never consumed)", async () => {
+    vi.mocked(prisma.medicationIntakeEvent.findMany).mockResolvedValue([
+      {
+        id: "r-taken",
+        medicationId: "med-1",
+        scheduledFor: new Date("2026-06-15T05:00:00.000Z"),
+        takenAt: new Date("2026-06-15T05:01:00.000Z"),
+        skipped: false,
+        syncVersion: 1,
+        createdAt: new Date("2026-06-15T05:01:00Z"),
+        attributionSource: "AUTO",
+        source: "WEB",
+        inventoryConsumption: [{ itemId: "item-1", units: 1 }],
+      },
+      {
+        id: "r-pending",
+        medicationId: "med-1",
+        scheduledFor: new Date("2026-06-15T05:00:30.000Z"),
+        takenAt: null,
+        skipped: false,
+        syncVersion: 0,
+        createdAt: new Date("2026-06-15T04:00:00Z"),
+        attributionSource: "AUTO",
+        source: "REMINDER",
+        inventoryConsumption: null,
+      },
+    ] as never);
+
+    const summary = await dedupeUserIntakeSlots("u1");
+    expect(summary.slotsCollapsed).toBe(1);
+    expect(summary.rowsSoftDeleted).toBe(1);
+    // The taken row wins; the pending loser carries no stamp → no refund.
+    expect(restoreForIntake).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/lib/medications/intake-slot-dedup.ts b/src/lib/medications/intake-slot-dedup.ts
index 1e475ad9f..073c47db4 100644
--- a/src/lib/medications/intake-slot-dedup.ts
+++ b/src/lib/medications/intake-slot-dedup.ts
@@ -44,6 +44,7 @@
  */
 import { prisma } from "@/lib/db";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
+import { restoreForIntake } from "@/lib/medications/inventory/consumption";
 import { isP2002 } from "@/lib/prisma-errors";
 import { annotate } from "@/lib/logging/context";
 import { getGlobalBoss } from "@/lib/jobs/boss-instance";
@@ -119,6 +120,12 @@ interface DedupIntakeRow {
    * takenAt`); a WEB or IMPORT ad-hoc row is a deliberate user shape.
    */
   source: string;
+  /**
+   * v1.16.10 — inventory consumption stamp. A stamped LOSER row refunds
+   * its consumed units before the tombstone (the winner keeps its own
+   * stamp untouched), so collapsing a duplicate never strands stock.
+   */
+  inventoryConsumption: unknown;
 }
 
 /**
@@ -266,6 +273,8 @@ export async function dedupeUserIntakeSlots(
         attributionSource: true,
         // v1.16.9 — write origin for the ad-hoc→pending convergence gate.
         source: true,
+        // v1.16.10 — stamped losers refund their consumption on collapse.
+        inventoryConsumption: true,
       },
       orderBy: { scheduledFor: "asc" },
     })) as DedupIntakeRow[];
@@ -347,6 +356,20 @@ export async function dedupeUserIntakeSlots(
         const winner = pickWinner(slotRows);
         const losers = slotRows.filter((r) => r.id !== winner.id);
 
+        // v1.16.10 — a stamped loser (a real taken row losing to a pin)
+        // refunds its consumed units before the tombstone; unstamped
+        // losers (pending / skipped / pre-stamp rows) skip the round
+        // trip. The winner keeps its own stamp untouched.
+        for (const loser of losers) {
+          if (loser.inventoryConsumption !== null) {
+            await restoreForIntake({
+              client: prisma,
+              userId,
+              eventId: loser.id,
+            });
+          }
+        }
+
         // Soft-delete every loser in one shot. Bump syncVersion so the
         // sync feed echoes a monotonic value and iOS drops the tombstone.
         const loserIds = losers.map((r) => r.id);
diff --git a/src/lib/medications/inventory/__tests__/consumption.test.ts b/src/lib/medications/inventory/__tests__/consumption.test.ts
new file mode 100644
index 000000000..8929d7bf6
--- /dev/null
+++ b/src/lib/medications/inventory/__tests__/consumption.test.ts
@@ -0,0 +1,655 @@
+/**
+ * v1.16.10 — consumption hook contract tests.
+ *
+ * Pins the exactly-once stamp semantics, the multi-unit FEFO selection
+ * with spillover + auto-open, the floor-at-zero partial stamp, and the
+ * symmetric restore (clamped refund, state re-derivation, stamp clear).
+ * The fake client mirrors the Prisma surface the hook touches and
+ * honours the orderBy specs the hook passes, so the selection order the
+ * tests assert is the order production gets from Postgres.
+ *
+ * Timezone-stable: every instant is an explicit UTC ISO string and the
+ * wall clock is pinned with fake timers.
+ */
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("@/lib/logging/context", () => ({
+  annotate: vi.fn(),
+}));
+
+import { Prisma } from "@/generated/prisma/client";
+import { annotate } from "@/lib/logging/context";
+import { consumeForIntake, restoreForIntake } from "../consumption";
+
+const NOW = new Date("2026-06-10T12:00:00.000Z");
+const MS_PER_DAY = 24 * 60 * 60 * 1000;
+
+interface FakeEvent {
+  id: string;
+  userId: string;
+  medicationId: string;
+  takenAt: Date | null;
+  skipped: boolean;
+  deletedAt: Date | null;
+  inventoryConsumption: unknown;
+}
+
+interface FakeItem {
+  id: string;
+  userId: string;
+  medicationId: string;
+  state: "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
+  unitsTotal: number;
+  unitsRemaining: number;
+  firstUseAt: Date | null;
+  expiresAt: Date | null;
+  printedExpiry: Date | null;
+  purchasedAt: Date | null;
+  createdAt: Date;
+}
+
+interface FakeState {
+  events: FakeEvent[];
+  items: FakeItem[];
+  unitsPerDose: number;
+}
+
+type OrderSpec = Record<
+  string,
+  "asc" | "desc" | { sort: "asc" | "desc"; nulls?: "first" | "last" }
+>;
+
+/** Honour the hook's orderBy the way Postgres would. */
+function sortRows(rows: FakeItem[], orderBy: OrderSpec[]): FakeItem[] {
+  return [...rows].sort((a, b) => {
+    for (const spec of orderBy) {
+      const [field, raw] = Object.entries(spec)[0];
+      const dir = typeof raw === "string" ? raw : raw.sort;
+      const nulls = typeof raw === "object" ? raw.nulls : undefined;
+      const av = a[field as keyof FakeItem] as Date | null;
+      const bv = b[field as keyof FakeItem] as Date | null;
+      if (av === null && bv === null) continue;
+      if (av === null) return nulls === "last" ? 1 : -1;
+      if (bv === null) return nulls === "last" ? -1 : 1;
+      const diff = av.getTime() - bv.getTime();
+      if (diff !== 0) return dir === "asc" ? diff : -diff;
+    }
+    return 0;
+  });
+}
+
+function makeClient(state: FakeState) {
+  return {
+    medication: {
+      findFirst: vi.fn(async () => ({ unitsPerDose: state.unitsPerDose })),
+    },
+    medicationIntakeEvent: {
+      findFirst: vi.fn(
+        async (args: { where: { id: string; userId: string } }) =>
+          state.events.find(
+            (e) => e.id === args.where.id && e.userId === args.where.userId,
+          ) ?? null,
+      ),
+      update: vi.fn(
+        async (args: {
+          where: { id: string };
+          data: Record<string, unknown>;
+        }) => {
+          const event = state.events.find((e) => e.id === args.where.id)!;
+          if ("inventoryConsumption" in args.data) {
+            event.inventoryConsumption =
+              args.data.inventoryConsumption === Prisma.DbNull
+                ? null
+                : args.data.inventoryConsumption;
+          }
+          return event;
+        },
+      ),
+    },
+    medicationInventoryItem: {
+      findMany: vi.fn(
+        async (args: {
+          where: {
+            userId: string;
+            medicationId: string;
+            state: FakeItem["state"];
+            unitsRemaining: { gt: number };
+          };
+          orderBy: OrderSpec[];
+        }) =>
+          sortRows(
+            state.items.filter(
+              (i) =>
+                i.userId === args.where.userId &&
+                i.medicationId === args.where.medicationId &&
+                i.state === args.where.state &&
+                i.unitsRemaining > args.where.unitsRemaining.gt,
+            ),
+            args.orderBy,
+          ),
+      ),
+      findFirst: vi.fn(
+        async (args: { where: { id: string; userId: string } }) =>
+          state.items.find(
+            (i) => i.id === args.where.id && i.userId === args.where.userId,
+          ) ?? null,
+      ),
+      update: vi.fn(
+        async (args: {
+          where: { id: string };
+          data: Partial<FakeItem>;
+        }) => {
+          const item = state.items.find((i) => i.id === args.where.id)!;
+          Object.assign(item, args.data);
+          return item;
+        },
+      ),
+    },
+  };
+}
+
+function takenEvent(overrides: Partial<FakeEvent> = {}): FakeEvent {
+  return {
+    id: "evt-1",
+    userId: "user-1",
+    medicationId: "med-1",
+    takenAt: NOW,
+    skipped: false,
+    deletedAt: null,
+    inventoryConsumption: null,
+    ...overrides,
+  };
+}
+
+function item(overrides: Partial<FakeItem> = {}): FakeItem {
+  return {
+    id: "item-1",
+    userId: "user-1",
+    medicationId: "med-1",
+    state: "ACTIVE",
+    unitsTotal: 10,
+    unitsRemaining: 10,
+    firstUseAt: null,
+    expiresAt: null,
+    printedExpiry: null,
+    purchasedAt: null,
+    createdAt: new Date("2026-06-01T00:00:00.000Z"),
+    ...overrides,
+  };
+}
+
+function consumeArgs(client: ReturnType<typeof makeClient>) {
+  return {
+    client: client as never,
+    userId: "user-1",
+    medicationId: "med-1",
+    eventId: "evt-1",
+    intakeAt: NOW,
+  };
+}
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  vi.useFakeTimers({ toFake: ["Date"] });
+  vi.setSystemTime(NOW);
+});
+
+afterEach(() => {
+  vi.useRealTimers();
+});
+
+describe("consumeForIntake", () => {
+  it("consumes unitsPerDose units from the open container and stamps the event", async () => {
+    const state: FakeState = {
+      unitsPerDose: 2,
+      events: [takenEvent()],
+      items: [
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsRemaining: 5,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+          expiresAt: new Date(NOW.getTime() + 27 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(3);
+    expect(state.items[0].state).toBe("IN_USE");
+    expect(state.events[0].inventoryConsumption).toEqual([
+      { itemId: "open", units: 2 },
+    ]);
+    expect(annotate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        action: { name: "medication.inventory.consumed" },
+        meta: expect.objectContaining({
+          medication_id: "med-1",
+          units: 2,
+          item_ids: ["open"],
+          auto_opened: 0,
+        }),
+      }),
+    );
+  });
+
+  it("prefers the IN_USE container over fresher ACTIVE stock", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [
+        item({ id: "sealed", state: "ACTIVE", unitsRemaining: 10 }),
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsRemaining: 2,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+          expiresAt: new Date(NOW.getTime() + 27 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    expect(state.items.find((i) => i.id === "open")!.unitsRemaining).toBe(1);
+    expect(state.items.find((i) => i.id === "sealed")!.unitsRemaining).toBe(10);
+  });
+
+  it("opens unopened stock first-expiry-first-out, null printed expiry last", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [
+        item({
+          id: "no-expiry",
+          printedExpiry: null,
+          createdAt: new Date("2026-05-01T00:00:00.000Z"),
+        }),
+        item({
+          id: "later-expiry",
+          printedExpiry: new Date("2027-06-01T00:00:00.000Z"),
+        }),
+        item({
+          id: "sooner-expiry",
+          printedExpiry: new Date("2026-09-01T00:00:00.000Z"),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    expect(
+      state.items.find((i) => i.id === "sooner-expiry")!.unitsRemaining,
+    ).toBe(9);
+    expect(state.items.find((i) => i.id === "no-expiry")!.unitsRemaining).toBe(
+      10,
+    );
+    expect(
+      state.items.find((i) => i.id === "later-expiry")!.unitsRemaining,
+    ).toBe(10);
+  });
+
+  it("auto-opens an ACTIVE container: firstUseAt = intakeAt, state IN_USE, expiresAt derived", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [item({ id: "sealed" })],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    const opened = state.items[0];
+    expect(opened.firstUseAt).toEqual(NOW);
+    expect(opened.state).toBe("IN_USE");
+    expect(opened.expiresAt?.getTime()).toBe(
+      NOW.getTime() + 30 * MS_PER_DAY,
+    );
+    expect(annotate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        meta: expect.objectContaining({ auto_opened: 1 }),
+      }),
+    );
+  });
+
+  it("lands a backdated auto-open straight in EXPIRED when its window has already lapsed", async () => {
+    const backdated = new Date(NOW.getTime() - 40 * MS_PER_DAY);
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent({ takenAt: backdated })],
+      items: [item({ id: "sealed" })],
+    };
+    const client = makeClient(state);
+    await consumeForIntake({
+      ...consumeArgs(client),
+      intakeAt: backdated,
+    });
+
+    const opened = state.items[0];
+    expect(opened.firstUseAt).toEqual(backdated);
+    // firstUseAt + 30 days lies in the past — the state machine says
+    // EXPIRED at the wall clock, and that is the honest answer.
+    expect(opened.state).toBe("EXPIRED");
+    expect(opened.unitsRemaining).toBe(9);
+    expect(state.events[0].inventoryConsumption).toEqual([
+      { itemId: "sealed", units: 1 },
+    ]);
+  });
+
+  it("spills across containers when the open one runs dry", async () => {
+    const state: FakeState = {
+      unitsPerDose: 3,
+      events: [takenEvent()],
+      items: [
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsRemaining: 1,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+          expiresAt: new Date(NOW.getTime() + 27 * MS_PER_DAY),
+        }),
+        item({ id: "sealed", unitsRemaining: 4, unitsTotal: 4 }),
+      ],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    const open = state.items.find((i) => i.id === "open")!;
+    const sealed = state.items.find((i) => i.id === "sealed")!;
+    expect(open.unitsRemaining).toBe(0);
+    expect(open.state).toBe("USED_UP");
+    expect(sealed.unitsRemaining).toBe(2);
+    expect(sealed.state).toBe("IN_USE");
+    expect(state.events[0].inventoryConsumption).toEqual([
+      { itemId: "open", units: 1 },
+      { itemId: "sealed", units: 2 },
+    ]);
+  });
+
+  it("floors at zero with a partial stamp when stock runs out — never negative, never an error", async () => {
+    const state: FakeState = {
+      unitsPerDose: 4,
+      events: [takenEvent()],
+      items: [
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsRemaining: 1,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+          expiresAt: new Date(NOW.getTime() + 27 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(0);
+    expect(state.items[0].state).toBe("USED_UP");
+    expect(state.events[0].inventoryConsumption).toEqual([
+      { itemId: "open", units: 1 },
+    ]);
+    expect(annotate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        meta: expect.objectContaining({ units: 1 }),
+      }),
+    );
+  });
+
+  it("stamps an empty consumption when no tracked stock exists (exactly-once gate)", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    expect(state.events[0].inventoryConsumption).toEqual([]);
+    expect(client.medicationInventoryItem.update).not.toHaveBeenCalled();
+  });
+
+  it("is a no-op on an already-stamped row (replay never double-decrements)", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [
+        takenEvent({ inventoryConsumption: [{ itemId: "open", units: 1 }] }),
+      ],
+      items: [
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsRemaining: 3,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+    await consumeForIntake(consumeArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(3);
+    expect(client.medicationInventoryItem.update).not.toHaveBeenCalled();
+    expect(client.medicationIntakeEvent.update).not.toHaveBeenCalled();
+  });
+
+  it.each([
+    ["pending", { takenAt: null }],
+    ["skipped", { skipped: true }],
+    ["tombstoned", { deletedAt: NOW }],
+  ])("never consumes for a %s row", async (_label, overrides) => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent(overrides as Partial<FakeEvent>)],
+      items: [item({ id: "sealed" })],
+    };
+    const client = makeClient(state);
+    await consumeForIntake(consumeArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(10);
+    expect(state.events[0].inventoryConsumption).toBeNull();
+  });
+
+  it("swallows unexpected failures and annotates consume_error", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [item({ id: "sealed" })],
+    };
+    const client = makeClient(state);
+    client.medicationInventoryItem.findMany.mockRejectedValue(
+      new Error("connection lost"),
+    );
+
+    await expect(consumeForIntake(consumeArgs(client))).resolves.toBeUndefined();
+    expect(annotate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        action: { name: "medication.inventory.consume_error" },
+      }),
+    );
+  });
+
+  it("uses the caller's interactive transaction when the client carries one", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [item({ id: "sealed" })],
+    };
+    const inner = makeClient(state);
+    const $transaction = vi.fn(async (fn: (tx: unknown) => Promise<void>) =>
+      fn(inner),
+    );
+    await consumeForIntake({
+      client: { ...inner, $transaction } as never,
+      userId: "user-1",
+      medicationId: "med-1",
+      eventId: "evt-1",
+      intakeAt: NOW,
+    });
+    expect($transaction).toHaveBeenCalledTimes(1);
+    expect(state.items[0].unitsRemaining).toBe(9);
+  });
+});
+
+describe("restoreForIntake", () => {
+  function restoreArgs(client: ReturnType<typeof makeClient>) {
+    return { client: client as never, userId: "user-1", eventId: "evt-1" };
+  }
+
+  it("refunds per stamp entry, re-derives the state and clears the stamp", async () => {
+    const state: FakeState = {
+      unitsPerDose: 2,
+      events: [
+        takenEvent({
+          inventoryConsumption: [{ itemId: "open", units: 2 }],
+        }),
+      ],
+      items: [
+        item({
+          id: "open",
+          state: "USED_UP",
+          unitsTotal: 4,
+          unitsRemaining: 0,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await restoreForIntake(restoreArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(2);
+    // USED_UP flips back to IN_USE — the window is still open.
+    expect(state.items[0].state).toBe("IN_USE");
+    expect(state.events[0].inventoryConsumption).toBeNull();
+    expect(annotate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        action: { name: "medication.inventory.restored" },
+        meta: expect.objectContaining({
+          medication_id: "med-1",
+          units: 2,
+          item_ids: ["open"],
+        }),
+      }),
+    );
+  });
+
+  it("clamps the refund to the item's capacity", async () => {
+    const state: FakeState = {
+      unitsPerDose: 2,
+      events: [
+        takenEvent({
+          inventoryConsumption: [{ itemId: "open", units: 2 }],
+        }),
+      ],
+      items: [
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsTotal: 4,
+          // A stock correction raised the count since the take.
+          unitsRemaining: 3,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await restoreForIntake(restoreArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(4);
+  });
+
+  it("re-derives EXPIRED when the refunded container's window has lapsed meanwhile", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [
+        takenEvent({
+          inventoryConsumption: [{ itemId: "open", units: 1 }],
+        }),
+      ],
+      items: [
+        item({
+          id: "open",
+          state: "USED_UP",
+          unitsTotal: 4,
+          unitsRemaining: 0,
+          firstUseAt: new Date(NOW.getTime() - 35 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await restoreForIntake(restoreArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(1);
+    expect(state.items[0].state).toBe("EXPIRED");
+  });
+
+  it("is a no-op when the row carries no stamp", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [item({ id: "open", unitsRemaining: 3 })],
+    };
+    const client = makeClient(state);
+    await restoreForIntake(restoreArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(3);
+    expect(client.medicationInventoryItem.update).not.toHaveBeenCalled();
+    expect(client.medicationIntakeEvent.update).not.toHaveBeenCalled();
+  });
+
+  it("skips a stamped container that was deleted since, still clearing the stamp", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [
+        takenEvent({
+          inventoryConsumption: [
+            { itemId: "gone", units: 1 },
+            { itemId: "open", units: 1 },
+          ],
+        }),
+      ],
+      items: [
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsRemaining: 1,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+    await restoreForIntake(restoreArgs(client));
+
+    expect(state.items[0].unitsRemaining).toBe(2);
+    expect(state.events[0].inventoryConsumption).toBeNull();
+  });
+
+  it("allows a re-take to consume afresh after a restore (skip → take cycle)", async () => {
+    const state: FakeState = {
+      unitsPerDose: 1,
+      events: [takenEvent()],
+      items: [
+        item({
+          id: "open",
+          state: "IN_USE",
+          unitsRemaining: 4,
+          unitsTotal: 4,
+          firstUseAt: new Date(NOW.getTime() - 3 * MS_PER_DAY),
+        }),
+      ],
+    };
+    const client = makeClient(state);
+
+    await consumeForIntake(consumeArgs(client));
+    expect(state.items[0].unitsRemaining).toBe(3);
+
+    await restoreForIntake(restoreArgs(client));
+    expect(state.items[0].unitsRemaining).toBe(4);
+    expect(state.events[0].inventoryConsumption).toBeNull();
+
+    await consumeForIntake(consumeArgs(client));
+    expect(state.items[0].unitsRemaining).toBe(3);
+    expect(state.events[0].inventoryConsumption).toEqual([
+      { itemId: "open", units: 1 },
+    ]);
+  });
+});
diff --git a/src/lib/medications/inventory/__tests__/service.test.ts b/src/lib/medications/inventory/__tests__/service.test.ts
index 1864a30c3..9ac65a5dd 100644
--- a/src/lib/medications/inventory/__tests__/service.test.ts
+++ b/src/lib/medications/inventory/__tests__/service.test.ts
@@ -14,118 +14,19 @@ vi.mock("@/lib/db", () => ({
 import { prisma } from "@/lib/db";
 import {
   buildCreateInventoryInput,
-  consumeOneDose,
   expireStaleInUseItems,
 } from "../service";
 
 const NOW = new Date("2026-05-14T12:00:00Z");
-const MS_PER_DAY = 24 * 60 * 60 * 1000;
 
 beforeEach(() => {
   vi.resetAllMocks();
 });
 
-describe("consumeOneDose", () => {
-  it("returns null when no eligible pen exists for the medication", async () => {
-    vi.mocked(prisma.medicationInventoryItem.findFirst).mockResolvedValueOnce(
-      null,
-    );
-    vi.mocked(prisma.medicationInventoryItem.findFirst).mockResolvedValueOnce(
-      null,
-    );
-
-    const result = await consumeOneDose({
-      userId: "u",
-      medicationId: "m",
-      intakeAt: NOW,
-    });
-    expect(result).toBeNull();
-    expect(prisma.medicationInventoryItem.update).not.toHaveBeenCalled();
-  });
-
-  it("flips an ACTIVE pen to IN_USE on first use", async () => {
-    // No IN_USE pen, fall back to ACTIVE.
-    vi.mocked(prisma.medicationInventoryItem.findFirst).mockResolvedValueOnce(
-      null,
-    );
-    vi.mocked(prisma.medicationInventoryItem.findFirst).mockResolvedValueOnce({
-      id: "inv-1",
-      state: "ACTIVE",
-      dosesTotal: 4,
-      dosesRemaining: 4,
-      firstUseAt: null,
-      printedExpiry: null,
-    } as never);
-    vi.mocked(prisma.medicationInventoryItem.update).mockResolvedValue({} as never);
-
-    const result = await consumeOneDose({
-      userId: "u",
-      medicationId: "m",
-      intakeAt: NOW,
-    });
-    expect(result).toEqual({ itemId: "inv-1", change: "first_use" });
-
-    const updateCall = vi.mocked(prisma.medicationInventoryItem.update).mock
-      .calls[0][0];
-    expect(updateCall.data).toMatchObject({
-      state: "IN_USE",
-      dosesRemaining: 3,
-      firstUseAt: NOW,
-    });
-  });
-
-  it("prefers the IN_USE pen with the earliest expiry", async () => {
-    const firstUse = new Date(NOW.getTime() - 5 * MS_PER_DAY);
-    vi.mocked(prisma.medicationInventoryItem.findFirst).mockResolvedValueOnce({
-      id: "inv-active",
-      state: "IN_USE",
-      dosesTotal: 4,
-      dosesRemaining: 3,
-      firstUseAt: firstUse,
-      printedExpiry: null,
-    } as never);
-    vi.mocked(prisma.medicationInventoryItem.update).mockResolvedValue({} as never);
-
-    const result = await consumeOneDose({
-      userId: "u",
-      medicationId: "m",
-      intakeAt: NOW,
-    });
-    expect(result).toEqual({ itemId: "inv-active", change: "consumed" });
-    expect(prisma.medicationInventoryItem.findFirst).toHaveBeenCalledTimes(1);
-  });
-
-  it("returns 'depleted' when the final dose is consumed", async () => {
-    const firstUse = new Date(NOW.getTime() - 5 * MS_PER_DAY);
-    vi.mocked(prisma.medicationInventoryItem.findFirst).mockResolvedValueOnce({
-      id: "inv-last",
-      state: "IN_USE",
-      dosesTotal: 4,
-      dosesRemaining: 1,
-      firstUseAt: firstUse,
-      printedExpiry: null,
-    } as never);
-    vi.mocked(prisma.medicationInventoryItem.update).mockResolvedValue({} as never);
-
-    const result = await consumeOneDose({
-      userId: "u",
-      medicationId: "m",
-      intakeAt: NOW,
-    });
-    expect(result).toEqual({ itemId: "inv-last", change: "depleted" });
-    const updateCall = vi.mocked(prisma.medicationInventoryItem.update).mock
-      .calls[0][0];
-    expect(updateCall.data).toMatchObject({
-      state: "USED_UP",
-      dosesRemaining: 0,
-    });
-  });
-});
-
 describe("expireStaleInUseItems", () => {
   it("transitions IN_USE rows whose deadline has lapsed via a single updateMany", async () => {
     // The selector `state = IN_USE AND expiresAt < now` already proves
-    // the row must transition to EXPIRED (IN_USE implies dosesRemaining
+    // the row must transition to EXPIRED (IN_USE implies unitsRemaining
     // > 0, and the expiresAt filter proves the deadline lapsed). Using
     // `updateMany` collapses N row round-trips into one.
     vi.mocked(prisma.medicationInventoryItem.updateMany).mockResolvedValue({
@@ -174,15 +75,17 @@ describe("buildCreateInventoryInput", () => {
     const input = buildCreateInventoryInput({
       userId: "u",
       medicationId: "m",
-      dosesTotal: 4,
+      unitsTotal: 4,
+      containerType: "PEN",
       printedExpiry: printed,
       purchasedAt: null,
       notes: null,
     });
     expect(input).toMatchObject({
       state: "ACTIVE",
-      dosesTotal: 4,
-      dosesRemaining: 4,
+      containerType: "PEN",
+      unitsTotal: 4,
+      unitsRemaining: 4,
       firstUseAt: null,
       expiresAt: printed,
     });
@@ -192,7 +95,8 @@ describe("buildCreateInventoryInput", () => {
     const input = buildCreateInventoryInput({
       userId: "u",
       medicationId: "m",
-      dosesTotal: 4,
+      unitsTotal: 4,
+      containerType: "OTHER",
       printedExpiry: null,
       purchasedAt: null,
       notes: null,
diff --git a/src/lib/medications/inventory/__tests__/state-machine.test.ts b/src/lib/medications/inventory/__tests__/state-machine.test.ts
index 120347070..2126d5b1b 100644
--- a/src/lib/medications/inventory/__tests__/state-machine.test.ts
+++ b/src/lib/medications/inventory/__tests__/state-machine.test.ts
@@ -4,8 +4,6 @@ import {
   computeExpiresAt,
   computeInventoryState,
   daysRemainingInUse,
-  decrementDose,
-  DEFAULT_IN_USE_WINDOW_DAYS,
   type InventoryItemView,
 } from "../state-machine";
 
@@ -16,8 +14,8 @@ const NOW_MS = NOW.getTime();
 function makeItem(overrides: Partial<InventoryItemView> = {}): InventoryItemView {
   return {
     state: "ACTIVE",
-    dosesTotal: 4,
-    dosesRemaining: 4,
+    unitsTotal: 4,
+    unitsRemaining: 4,
     firstUseAt: null,
     printedExpiry: null,
     ...overrides,
@@ -58,17 +56,17 @@ describe("computeInventoryState", () => {
     expect(computeInventoryState(item, NOW_MS)).toBe("EXPIRED");
   });
 
-  it("returns USED_UP when dosesRemaining is zero (terminal — outranks EXPIRED)", () => {
+  it("returns USED_UP when unitsRemaining is zero (terminal — outranks EXPIRED)", () => {
     const item = makeItem({
-      dosesRemaining: 0,
+      unitsRemaining: 0,
       firstUseAt: new Date(NOW_MS - 31 * MS_PER_DAY),
     });
     expect(computeInventoryState(item, NOW_MS)).toBe("USED_UP");
   });
 
-  it("returns USED_UP even when printed expiry has lapsed (dosesRemaining wins)", () => {
+  it("returns USED_UP even when printed expiry has lapsed (unitsRemaining wins)", () => {
     const item = makeItem({
-      dosesRemaining: 0,
+      unitsRemaining: 0,
       printedExpiry: new Date(NOW_MS - 5 * MS_PER_DAY),
     });
     expect(computeInventoryState(item, NOW_MS)).toBe("USED_UP");
@@ -122,74 +120,6 @@ describe("computeExpiresAt", () => {
   });
 });
 
-describe("decrementDose", () => {
-  it("first_use — flips ACTIVE → IN_USE and sets firstUseAt", () => {
-    const item = makeItem();
-    const result = decrementDose(item, NOW);
-
-    expect(result.change).toBe("first_use");
-    expect(result.item.state).toBe("IN_USE");
-    expect(result.item.firstUseAt).toEqual(NOW);
-    expect(result.item.dosesRemaining).toBe(3);
-    expect(result.item.expiresAt?.getTime()).toBe(
-      NOW_MS + DEFAULT_IN_USE_WINDOW_DAYS * MS_PER_DAY,
-    );
-  });
-
-  it("consumed — IN_USE pen with doses left stays IN_USE", () => {
-    const firstUse = new Date(NOW_MS - 3 * MS_PER_DAY);
-    const item = makeItem({
-      state: "IN_USE",
-      dosesRemaining: 3,
-      firstUseAt: firstUse,
-    });
-    const result = decrementDose(item, NOW);
-
-    expect(result.change).toBe("consumed");
-    expect(result.item.state).toBe("IN_USE");
-    expect(result.item.firstUseAt).toEqual(firstUse);
-    expect(result.item.dosesRemaining).toBe(2);
-  });
-
-  it("depleted — final dose flips state to USED_UP", () => {
-    const firstUse = new Date(NOW_MS - 3 * MS_PER_DAY);
-    const item = makeItem({
-      state: "IN_USE",
-      dosesRemaining: 1,
-      firstUseAt: firstUse,
-    });
-    const result = decrementDose(item, NOW);
-
-    expect(result.change).toBe("depleted");
-    expect(result.item.state).toBe("USED_UP");
-    expect(result.item.dosesRemaining).toBe(0);
-  });
-
-  it("does not mutate its input", () => {
-    const firstUse = new Date(NOW_MS - 3 * MS_PER_DAY);
-    const item = makeItem({
-      state: "IN_USE",
-      dosesRemaining: 3,
-      firstUseAt: firstUse,
-    });
-    const snapshot = JSON.stringify(item);
-    decrementDose(item, NOW);
-    expect(JSON.stringify(item)).toBe(snapshot);
-  });
-
-  it("clamps dosesRemaining at zero even if called on an already-empty pen", () => {
-    const item = makeItem({
-      state: "USED_UP",
-      dosesRemaining: 0,
-      firstUseAt: new Date(NOW_MS - 5 * MS_PER_DAY),
-    });
-    const result = decrementDose(item, NOW);
-
-    expect(result.item.dosesRemaining).toBe(0);
-    expect(result.item.state).toBe("USED_UP");
-  });
-});
-
 describe("daysRemainingInUse", () => {
   it("returns null for an ACTIVE (unopened) pen", () => {
     expect(daysRemainingInUse(makeItem(), NOW_MS)).toBeNull();
@@ -204,7 +134,7 @@ describe("daysRemainingInUse", () => {
 
   it("returns null for a USED_UP pen", () => {
     const item = makeItem({
-      dosesRemaining: 0,
+      unitsRemaining: 0,
       firstUseAt: new Date(NOW_MS - 5 * MS_PER_DAY),
     });
     expect(daysRemainingInUse(item, NOW_MS)).toBeNull();
diff --git a/src/lib/medications/inventory/consumption.ts b/src/lib/medications/inventory/consumption.ts
new file mode 100644
index 000000000..c80a38d2b
--- /dev/null
+++ b/src/lib/medications/inventory/consumption.ts
@@ -0,0 +1,377 @@
+/**
+ * v1.16.10 — per-intake inventory consumption + restore.
+ *
+ * The single write path between intake events and inventory items.
+ * Every seam that flips an intake event to TAKEN calls
+ * `consumeForIntake`; every seam that takes a row OUT of taken
+ * (skip toggle, edit, delete, bulk delete, slot-dedup tombstone)
+ * calls `restoreForIntake`. No other module may write
+ * `medicationInventoryItem` rows outside the inventory CRUD routes —
+ * a convention test pins that.
+ *
+ * Exactly-once semantics hang off the consumption STAMP — the
+ * `MedicationIntakeEvent.inventoryConsumption` Json column holding
+ * `[{itemId, units}]`:
+ *
+ *   - `consumeForIntake` is a no-op on a stamped row, so idempotent
+ *     replays (iOS sync, Telegram redelivery, double taps) can call it
+ *     freely and the stock only ever moves once per taken event.
+ *   - `restoreForIntake` refunds exactly what the stamp recorded and
+ *     clears it, so a later re-take consumes afresh. The stamp freezes
+ *     history: editing `Medication.unitsPerDose` after the fact never
+ *     changes what an already-taken dose consumed or refunds.
+ *
+ * Consumption is in UNITS (`Medication.unitsPerDose` per dose), pulled
+ * from the open container first, then FEFO over unopened stock with
+ * auto-open, spilling across containers, flooring at zero when the
+ * tracked stock runs out (partial stamp — never negative, never an
+ * error).
+ *
+ * Both functions are best-effort and NEVER throw: a failure annotates
+ * (`medication.inventory.consume_error` / `.restore_error`) and
+ * returns — the intake write is the source of truth, the inventory is
+ * an opt-in companion that must never block a dose record.
+ */
+
+import { Prisma, type PrismaClient } from "@/generated/prisma/client";
+import { annotate } from "@/lib/logging/context";
+import {
+  computeExpiresAt,
+  computeInventoryState,
+} from "./state-machine";
+
+/** The Prisma surface the consumption hook needs. A bare transaction
+ *  client satisfies it; the base client additionally carries
+ *  `$transaction`, which the hook uses to keep the item updates and
+ *  the stamp write atomic. */
+type ConsumptionClient = Pick<
+  PrismaClient,
+  "medication" | "medicationIntakeEvent" | "medicationInventoryItem"
+> &
+  Partial<Pick<PrismaClient, "$transaction">>;
+
+type TxClient = Pick<
+  PrismaClient,
+  "medication" | "medicationIntakeEvent" | "medicationInventoryItem"
+>;
+
+/** One consumed slice of the stamp: `units` taken from `itemId`. */
+export interface InventoryConsumptionEntry {
+  itemId: string;
+  units: number;
+}
+
+/**
+ * Run `fn` atomically. When the caller hands us the base client we
+ * open an interactive transaction; when it hands us a transaction
+ * client (no `$transaction` on it) the caller's transaction already
+ * provides the atomicity and we run inline.
+ */
+async function runAtomically<T>(
+  client: ConsumptionClient,
+  fn: (tx: TxClient) => Promise<T>,
+): Promise<T> {
+  if (typeof client.$transaction === "function") {
+    return client.$transaction((tx) => fn(tx as TxClient));
+  }
+  return fn(client);
+}
+
+/** Parse a stamp column value defensively — a malformed stamp refunds
+ *  nothing rather than throwing. */
+function parseStamp(value: Prisma.JsonValue | null): InventoryConsumptionEntry[] | null {
+  if (value === null || !Array.isArray(value)) return null;
+  const entries: InventoryConsumptionEntry[] = [];
+  for (const raw of value) {
+    if (
+      typeof raw === "object" &&
+      raw !== null &&
+      !Array.isArray(raw) &&
+      typeof (raw as { itemId?: unknown }).itemId === "string" &&
+      typeof (raw as { units?: unknown }).units === "number" &&
+      Number.isFinite((raw as { units: number }).units) &&
+      (raw as { units: number }).units > 0
+    ) {
+      entries.push({
+        itemId: (raw as { itemId: string }).itemId,
+        units: Math.floor((raw as { units: number }).units),
+      });
+    }
+  }
+  return entries;
+}
+
+/**
+ * Consume the medication's `unitsPerDose` units for one taken intake
+ * event and stamp the event with what was consumed.
+ *
+ * No-op unless the event row is live (`deletedAt: null`), taken
+ * (`takenAt` set), non-skipped, and UNSTAMPED — the stamp is the
+ * exactly-once gate, so replays and re-posts never double-decrement.
+ *
+ * Container selection:
+ *   1. the open container — IN_USE with `unitsRemaining > 0`, earliest
+ *      `expiresAt` first (createdAt tiebreak);
+ *   2. then FEFO over unopened ACTIVE stock — `printedExpiry` asc with
+ *      nulls last, then `purchasedAt` asc (nulls last), then
+ *      `createdAt` asc. Pulling from an ACTIVE container auto-opens it
+ *      (`firstUseAt = intakeAt`, state via the state machine — a
+ *      backdated intake can land it straight in EXPIRED when the
+ *      30-day window has already lapsed; that is correct).
+ *
+ * Consumption spills: when the current container holds fewer units
+ * than still owed, it drains to zero and the next container covers the
+ * rest. When the tracked stock runs out the consumption floors at
+ * zero overall — the stamp records the partial amount, no error, no
+ * negative counts.
+ */
+export async function consumeForIntake(input: {
+  client: ConsumptionClient;
+  userId: string;
+  medicationId: string;
+  eventId: string;
+  intakeAt: Date;
+}): Promise<void> {
+  const { client, userId, medicationId, eventId, intakeAt } = input;
+  try {
+    await runAtomically(client, async (tx) => {
+      const event = await tx.medicationIntakeEvent.findFirst({
+        where: { id: eventId, userId },
+        select: {
+          id: true,
+          medicationId: true,
+          takenAt: true,
+          skipped: true,
+          deletedAt: true,
+          inventoryConsumption: true,
+        },
+      });
+      if (
+        !event ||
+        event.deletedAt !== null ||
+        event.takenAt === null ||
+        event.skipped ||
+        event.inventoryConsumption !== null
+      ) {
+        return;
+      }
+
+      const medication = await tx.medication.findFirst({
+        where: { id: medicationId, userId },
+        select: { unitsPerDose: true },
+      });
+      if (!medication) return;
+      const unitsPerDose = Math.max(1, medication.unitsPerDose);
+
+      // Candidate containers, in consumption order: the open container
+      // first (earliest in-use deadline), then FEFO over unopened
+      // stock. Both lists are loaded inside the transaction so the
+      // updates apply to the rows just read.
+      const inUse = await tx.medicationInventoryItem.findMany({
+        where: {
+          userId,
+          medicationId,
+          state: "IN_USE",
+          unitsRemaining: { gt: 0 },
+        },
+        orderBy: [
+          { expiresAt: { sort: "asc", nulls: "last" } },
+          { createdAt: "asc" },
+        ],
+      });
+      const active = await tx.medicationInventoryItem.findMany({
+        where: {
+          userId,
+          medicationId,
+          state: "ACTIVE",
+          unitsRemaining: { gt: 0 },
+        },
+        orderBy: [
+          { printedExpiry: { sort: "asc", nulls: "last" } },
+          { purchasedAt: { sort: "asc", nulls: "last" } },
+          { createdAt: "asc" },
+        ],
+      });
+
+      const stamp: InventoryConsumptionEntry[] = [];
+      const itemIds: string[] = [];
+      let autoOpened = 0;
+      let owed = unitsPerDose;
+      // State derives at the WALL clock, not the intake instant: a
+      // backdated take that auto-opens a container starts its in-use
+      // window at the (past) intakeAt, so the container can land
+      // straight in EXPIRED when that window has already lapsed by now
+      // — correct, the daily cron would flip it on the next sweep
+      // anyway.
+      const nowMs = Date.now();
+
+      for (const item of [...inUse, ...active]) {
+        if (owed <= 0) break;
+        const take = Math.min(owed, item.unitsRemaining);
+        if (take <= 0) continue;
+
+        const wasUnopened = item.firstUseAt === null;
+        const nextFirstUseAt = item.firstUseAt ?? intakeAt;
+        const nextUnitsRemaining = item.unitsRemaining - take;
+        const nextExpiresAt = computeExpiresAt(
+          nextFirstUseAt,
+          item.printedExpiry,
+        );
+        const nextState = computeInventoryState(
+          {
+            state: item.state,
+            unitsTotal: item.unitsTotal,
+            unitsRemaining: nextUnitsRemaining,
+            firstUseAt: nextFirstUseAt,
+            printedExpiry: item.printedExpiry,
+          },
+          nowMs,
+        );
+
+        await tx.medicationInventoryItem.update({
+          where: { id: item.id },
+          data: {
+            state: nextState,
+            unitsRemaining: nextUnitsRemaining,
+            firstUseAt: nextFirstUseAt,
+            expiresAt: nextExpiresAt,
+          },
+        });
+
+        stamp.push({ itemId: item.id, units: take });
+        itemIds.push(item.id);
+        if (wasUnopened) autoOpened += 1;
+        owed -= take;
+      }
+
+      // Stamp the event even when nothing (or only part) could be
+      // consumed: the stamp is the exactly-once gate, and a dose taken
+      // with no tracked stock must not retro-consume containers
+      // registered later when a sync replay revisits the row.
+      await tx.medicationIntakeEvent.update({
+        where: { id: event.id },
+        data: { inventoryConsumption: stamp as unknown as Prisma.InputJsonValue },
+      });
+
+      annotate({
+        action: { name: "medication.inventory.consumed" },
+        meta: {
+          medication_id: medicationId,
+          units: unitsPerDose - owed,
+          item_ids: itemIds,
+          auto_opened: autoOpened,
+        },
+      });
+    });
+  } catch (err) {
+    annotate({
+      action: { name: "medication.inventory.consume_error" },
+      meta: {
+        medication_id: medicationId,
+        event_id: eventId,
+        message: err instanceof Error ? err.message : String(err),
+      },
+    });
+  }
+}
+
+/**
+ * Refund the consumption a stamped intake event recorded and clear
+ * the stamp.
+ *
+ * No stamp = no-op (the row never consumed, or was already restored).
+ * Each refund is clamped to the item's `unitsTotal` so a stock
+ * correction in between can never overfill a container; the state
+ * re-derives through the state machine, so a USED_UP container whose
+ * units come back flips to IN_USE (or EXPIRED when its clock has
+ * lapsed meanwhile). A stamped item that was deleted since is skipped.
+ */
+export async function restoreForIntake(input: {
+  client: ConsumptionClient;
+  userId: string;
+  eventId: string;
+}): Promise<void> {
+  const { client, userId, eventId } = input;
+  try {
+    await runAtomically(client, async (tx) => {
+      const event = await tx.medicationIntakeEvent.findFirst({
+        where: { id: eventId, userId },
+        select: {
+          id: true,
+          medicationId: true,
+          inventoryConsumption: true,
+        },
+      });
+      if (!event) return;
+      const stamp = parseStamp(event.inventoryConsumption);
+      if (stamp === null || stamp.length === 0) {
+        // Clear an empty/malformed stamp so a later re-take can
+        // consume afresh; a NULL stamp is already clear.
+        if (event.inventoryConsumption !== null) {
+          await tx.medicationIntakeEvent.update({
+            where: { id: event.id },
+            data: { inventoryConsumption: Prisma.DbNull },
+          });
+        }
+        return;
+      }
+
+      const nowMs = Date.now();
+      let refunded = 0;
+      const itemIds: string[] = [];
+      for (const entry of stamp) {
+        const item = await tx.medicationInventoryItem.findFirst({
+          where: { id: entry.itemId, userId },
+        });
+        if (!item) continue; // container deleted since — nothing to refund.
+
+        const nextUnitsRemaining = Math.min(
+          item.unitsTotal,
+          item.unitsRemaining + entry.units,
+        );
+        const refundedHere = nextUnitsRemaining - item.unitsRemaining;
+        const nextState = computeInventoryState(
+          {
+            state: item.state,
+            unitsTotal: item.unitsTotal,
+            unitsRemaining: nextUnitsRemaining,
+            firstUseAt: item.firstUseAt,
+            printedExpiry: item.printedExpiry,
+          },
+          nowMs,
+        );
+        await tx.medicationInventoryItem.update({
+          where: { id: item.id },
+          data: {
+            state: nextState,
+            unitsRemaining: nextUnitsRemaining,
+          },
+        });
+        refunded += refundedHere;
+        itemIds.push(item.id);
+      }
+
+      await tx.medicationIntakeEvent.update({
+        where: { id: event.id },
+        data: { inventoryConsumption: Prisma.DbNull },
+      });
+
+      annotate({
+        action: { name: "medication.inventory.restored" },
+        meta: {
+          medication_id: event.medicationId,
+          units: refunded,
+          item_ids: itemIds,
+        },
+      });
+    });
+  } catch (err) {
+    annotate({
+      action: { name: "medication.inventory.restore_error" },
+      meta: {
+        event_id: eventId,
+        message: err instanceof Error ? err.message : String(err),
+      },
+    });
+  }
+}
diff --git a/src/lib/medications/inventory/service.ts b/src/lib/medications/inventory/service.ts
index 58e9f8bc7..83df1c318 100644
--- a/src/lib/medications/inventory/service.ts
+++ b/src/lib/medications/inventory/service.ts
@@ -1,97 +1,19 @@
 /**
  * v1.4.25 W19b — inventory persistence helpers.
  *
- * Thin layer on top of Prisma that the route handlers and the
- * intake hook compose. Keeps the state-machine math (pure) separate
- * from the I/O (here), so unit tests on the math don't need a DB.
+ * Thin layer on top of Prisma that the route handlers compose. Keeps
+ * the state-machine math (pure) separate from the I/O (here), so unit
+ * tests on the math don't need a DB.
+ *
+ * v1.16.10 — the per-intake consumption hook moved to
+ * `./consumption.ts` (multi-unit, FEFO, spillover, stamped on the
+ * intake event); this module keeps the expire cron and the
+ * create-input builder.
  */
 
 import { prisma } from "@/lib/db";
-import {
-  computeExpiresAt,
-  decrementDose,
-  type DecrementOutcome,
-} from "./state-machine";
-
-/**
- * Consume one dose from the user's active in-use pen for the given
- * medication. Called from the intake POST handler after the intake
- * event has been created.
- *
- * Selection policy:
- *   1. Prefer the IN_USE pen with the earliest `expiresAt` — that's
- *      the pen the user is currently working through.
- *   2. Fall back to the oldest ACTIVE pen (FIFO consumption — the
- *      pen that was purchased first gets opened first). The intake
- *      flips it ACTIVE → IN_USE and sets firstUseAt.
- *   3. If no eligible pen exists, this is a no-op. The user just
- *      logged an intake without a tracked pen — perfectly valid
- *      since inventory is opt-in per the W19a doses-per-unit
- *      design.
- *
- * The function intentionally only updates one pen per intake — if a
- * user double-doses (rare), they need to record two intake events
- * and the second one will pick up the same or a new pen.
- */
-export async function consumeOneDose(input: {
-  userId: string;
-  medicationId: string;
-  intakeAt: Date;
-}): Promise<{
-  itemId: string;
-  change: DecrementOutcome;
-} | null> {
-  const { userId, medicationId, intakeAt } = input;
-
-  // Prefer the IN_USE pen with the earliest expiry; tie-break by
-  // createdAt ascending.
-  const inUsePen = await prisma.medicationInventoryItem.findFirst({
-    where: {
-      userId,
-      medicationId,
-      state: "IN_USE",
-      dosesRemaining: { gt: 0 },
-    },
-    orderBy: [{ expiresAt: "asc" }, { createdAt: "asc" }],
-  });
-
-  const target =
-    inUsePen ??
-    (await prisma.medicationInventoryItem.findFirst({
-      where: {
-        userId,
-        medicationId,
-        state: "ACTIVE",
-        dosesRemaining: { gt: 0 },
-      },
-      orderBy: [{ purchasedAt: "asc" }, { createdAt: "asc" }],
-    }));
-
-  if (!target) return null;
-
-  const { item: nextValues, change } = decrementDose(
-    {
-      state: target.state,
-      dosesTotal: target.dosesTotal,
-      dosesRemaining: target.dosesRemaining,
-      firstUseAt: target.firstUseAt,
-      printedExpiry: target.printedExpiry,
-    },
-    intakeAt,
-  );
-
-  await prisma.medicationInventoryItem.update({
-    where: { id: target.id },
-    data: {
-      state: nextValues.state,
-      dosesRemaining: nextValues.dosesRemaining,
-      firstUseAt: nextValues.firstUseAt,
-      expiresAt: nextValues.expiresAt,
-    },
-  });
-
-  return { itemId: target.id, change };
-}
+import type { MedicationContainerType } from "@/generated/prisma/client";
+import { computeExpiresAt } from "./state-machine";
 
 /**
  * Daily cron pass — flip any IN_USE rows whose 30-day window has
@@ -111,10 +33,10 @@ export async function expireStaleInUseItems(input: {
   // selector + state-machine semantics line up here — every row that
   // matches `state = IN_USE AND expiresAt < now` is also a row that
   // `computeInventoryState` would classify EXPIRED (clause 2 or 3),
-  // because IN_USE implies `dosesRemaining > 0` (decrementDose flips
-  // an empty pen to USED_UP) and the `expiresAt` filter already
-  // proves the printed-expiry-or-window deadline has lapsed. EXPIRED
-  // rows are already terminal; USED_UP rows are off-window by
+  // because IN_USE implies `unitsRemaining > 0` (the consumption hook
+  // flips an empty container to USED_UP) and the `expiresAt` filter
+  // already proves the printed-expiry-or-window deadline has lapsed.
+  // EXPIRED rows are already terminal; USED_UP rows are off-window by
   // definition. Use a single `updateMany` instead of one update per
   // row — the daily cron sweep ran N round-trips for nothing.
   const result = await prisma.medicationInventoryItem.updateMany({
@@ -136,7 +58,8 @@ export async function expireStaleInUseItems(input: {
 export function buildCreateInventoryInput(input: {
   userId: string;
   medicationId: string;
-  dosesTotal: number;
+  unitsTotal: number;
+  containerType: MedicationContainerType;
   printedExpiry: Date | null;
   purchasedAt: Date | null;
   notes: string | null;
@@ -145,8 +68,9 @@ export function buildCreateInventoryInput(input: {
     userId: input.userId,
     medicationId: input.medicationId,
     state: "ACTIVE" as const,
-    dosesTotal: input.dosesTotal,
-    dosesRemaining: input.dosesTotal,
+    containerType: input.containerType,
+    unitsTotal: input.unitsTotal,
+    unitsRemaining: input.unitsTotal,
     firstUseAt: null,
     printedExpiry: input.printedExpiry,
     purchasedAt: input.purchasedAt,
diff --git a/src/lib/medications/inventory/state-machine.ts b/src/lib/medications/inventory/state-machine.ts
index a095f05a5..83d50980d 100644
--- a/src/lib/medications/inventory/state-machine.ts
+++ b/src/lib/medications/inventory/state-machine.ts
@@ -2,16 +2,22 @@
  * v1.4.25 W19b — pen / vial inventory state machine.
  *
  * Pure functions over a minimal `InventoryItemView` shape — no DB
- * access, no Prisma imports. The route handlers and the daily expire
- * cron both compose this module with their own persistence layer.
+ * access, no Prisma imports. The route handlers, the consumption hook
+ * (`./consumption.ts`), and the daily expire cron all compose this
+ * module with their own persistence layer.
  *
  * Decision tree (in evaluation order):
- *   1. dosesRemaining === 0           → USED_UP   (terminal)
+ *   1. unitsRemaining === 0           → USED_UP   (terminal)
  *   2. printedExpiry  && now > expiry → EXPIRED   (printed label trumps clock)
  *   3. firstUseAt && now > firstUseAt + IN_USE_WINDOW_MS → EXPIRED
  *   4. firstUseAt is set              → IN_USE
  *   5. otherwise                      → ACTIVE
  *
+ * v1.16.10 — the item counts UNITS (tablets / ampoules / puffs), not
+ * doses; `Medication.unitsPerDose` maps between the two. The state
+ * machine is unit-agnostic — it only cares whether the count reached
+ * zero.
+ *
  * The window length is fixed at 30 days per EMA EPAR §6.3 for
  * Mounjaro KwikPen / Saxenda / Trulicity. Ozempic ships with a 56-day
  * window per its own EPAR — that drug-specific override is *not*
@@ -38,8 +44,8 @@ const MS_PER_DAY = 24 * 60 * 60 * 1000;
  */
 export interface InventoryItemView {
   state: MedicationInventoryState;
-  dosesTotal: number;
-  dosesRemaining: number;
+  unitsTotal: number;
+  unitsRemaining: number;
   firstUseAt: Date | null;
   printedExpiry: Date | null;
 }
@@ -49,26 +55,26 @@ export interface InventoryItemView {
  *
  * The function is pure — given the same input it always returns the
  * same state — so the caller can re-evaluate as often as it wants
- * without side-effects. The expire-cron and the intake-hook both use
- * this same evaluator; the only difference is what they do with the
- * result.
+ * without side-effects. The expire-cron and the consumption hook both
+ * use this same evaluator; the only difference is what they do with
+ * the result.
  */
 export function computeInventoryState(
   item: InventoryItemView,
   nowMs: number,
   inUseWindowDays: number = DEFAULT_IN_USE_WINDOW_DAYS,
 ): MedicationInventoryState {
-  // (1) Terminal — once a pen is used up, it stays used up. The
-  // printed expiry on an empty pen is irrelevant; the EXPIRED state
-  // exists to warn the user not to inject from a pen that's still
-  // got doses but has gone stale, and an empty pen has neither
+  // (1) Terminal — once a container is used up, it stays used up. The
+  // printed expiry on an empty container is irrelevant; the EXPIRED
+  // state exists to warn the user not to dose from a container that's
+  // still got units but has gone stale, and an empty one has neither
   // problem.
-  if (item.dosesRemaining <= 0) {
+  if (item.unitsRemaining <= 0) {
     return "USED_UP";
   }
 
-  // (2) Printed expiry trumps the in-use clock. A pen whose carton
-  // expiry has lapsed is EXPIRED even if it was never opened.
+  // (2) Printed expiry trumps the in-use clock. A container whose
+  // carton expiry has lapsed is EXPIRED even if it was never opened.
   if (item.printedExpiry && nowMs > item.printedExpiry.getTime()) {
     return "EXPIRED";
   }
@@ -91,9 +97,9 @@ export function computeInventoryState(
 /**
  * Compute the `expiresAt` column. It's the min of the in-use
  * deadline (firstUseAt + window) and the printed expiry — whichever
- * lands first. If the pen has never been opened we fall back to the
- * printed expiry alone (in-use clock hasn't started). If neither is
- * set we return null so the daily expire-cron has nothing to scan.
+ * lands first. If the container has never been opened we fall back to
+ * the printed expiry alone (in-use clock hasn't started). If neither
+ * is set we return null so the daily expire-cron has nothing to scan.
  */
 export function computeExpiresAt(
   firstUseAt: Date | null,
@@ -112,93 +118,10 @@ export function computeExpiresAt(
   return inUseDeadline ?? printedExpiry ?? null;
 }
 
-/**
- * Outcome of decrementing a dose. `first_use` fires when a pen
- * transitions from ACTIVE → IN_USE (this intake event was its first
- * use). `consumed` is the routine case. `depleted` fires on the
- * intake that brings dosesRemaining to zero.
- */
-export type DecrementOutcome = "first_use" | "consumed" | "depleted";
-
-/**
- * Result of `decrementDose`. The returned `item` is a fresh object —
- * the function does not mutate its input. The caller persists the
- * returned shape (typically via a `prisma.medicationInventoryItem.update`).
- */
-export interface DecrementResult {
-  item: {
-    state: MedicationInventoryState;
-    dosesRemaining: number;
-    firstUseAt: Date | null;
-    expiresAt: Date | null;
-  };
-  change: DecrementOutcome;
-}
-
-/**
- * Consume one dose from a pen.
- *
- * If the pen is ACTIVE (never opened), this intake event sets
- * `firstUseAt = intakeAt` and starts the 30-day clock. If the pen
- * was already IN_USE, only `dosesRemaining` decrements. When the
- * last dose is taken, the state moves to USED_UP and `expiresAt`
- * is left untouched (the in-use window is no longer meaningful for
- * an empty pen, but persisting the deadline preserves the audit
- * trail).
- *
- * The function is defensive — if called on an EXPIRED or USED_UP
- * pen it still decrements (caller's job to gate). The state
- * recomputation respects whatever the final dose count + clock say.
- */
-export function decrementDose(
-  item: InventoryItemView,
-  intakeAt: Date,
-  inUseWindowDays: number = DEFAULT_IN_USE_WINDOW_DAYS,
-): DecrementResult {
-  const wasFirstUse = item.firstUseAt === null;
-  const nextFirstUseAt = item.firstUseAt ?? intakeAt;
-  const nextDosesRemaining = Math.max(0, item.dosesRemaining - 1);
-  const nextExpiresAt = computeExpiresAt(
-    nextFirstUseAt,
-    item.printedExpiry,
-    inUseWindowDays,
-  );
-
-  const projected: InventoryItemView = {
-    state: item.state,
-    dosesTotal: item.dosesTotal,
-    dosesRemaining: nextDosesRemaining,
-    firstUseAt: nextFirstUseAt,
-    printedExpiry: item.printedExpiry,
-  };
-  const nextState = computeInventoryState(
-    projected,
-    intakeAt.getTime(),
-    inUseWindowDays,
-  );
-
-  const change: DecrementOutcome =
-    nextDosesRemaining === 0
-      ? "depleted"
-      : wasFirstUse
-        ? "first_use"
-        : "consumed";
-
-  return {
-    item: {
-      state: nextState,
-      dosesRemaining: nextDosesRemaining,
-      firstUseAt: nextFirstUseAt,
-      expiresAt: nextExpiresAt,
-    },
-    change,
-  };
-}
-
 /**
  * Whole-days remaining in the 30-day in-use window, rounded toward
- * zero. Returns null when the pen is not currently IN_USE (the UI
- * surface for ACTIVE / EXPIRED / USED_UP shows a different label).
+ * zero. Returns null when the container is not currently IN_USE (the
+ * UI surface for ACTIVE / EXPIRED / USED_UP shows a different label).
  *
  * The day count is computed against the in-use deadline only —
  * the printed expiry is its own separate countdown surfaced as the
@@ -229,7 +152,7 @@ export function daysRemainingInUse(
   // (the inventory disclosure UI on the medication card) supply just
   // `firstUseAt` and have already filtered on state === "IN_USE" before
   // reaching here. The gate is silently skipped for the thin form.
-  if ("state" in item && "dosesRemaining" in item) {
+  if ("state" in item && "unitsRemaining" in item) {
     const state = computeInventoryState(
       { ...item, firstUseAt },
       nowMs,
diff --git a/src/lib/openapi/routes/medications.ts b/src/lib/openapi/routes/medications.ts
index 2bec317a1..52791dff5 100644
--- a/src/lib/openapi/routes/medications.ts
+++ b/src/lib/openapi/routes/medications.ts
@@ -11,7 +11,10 @@ import {
   createMedicationSchema,
   updateMedicationSchema,
   intakeSchema,
+  createInventoryItemSchema,
+  updateInventoryItemSchema,
   MEDICATION_CATEGORY_VALUES,
+  MEDICATION_CONTAINER_TYPE_VALUES,
   MEDICATION_TREATMENT_CLASS_VALUES,
 } from "@/lib/validations/medication";
 import { medicationExtractionSchema } from "@/lib/ai/coach/medication-extract-prompt";
@@ -139,6 +142,12 @@ export const medicationResource = z
       .describe(
         "Doses per pen / vial for inventory tracking. NULL = inventory tracking off.",
       ),
+    unitsPerDose: z
+      .number()
+      .int()
+      .describe(
+        "v1.16.10 — inventory units one dose consumes (e.g. 2 tablets of 2 mg for a 4 mg dose). Default 1. The intake consumption hook decrements this many units per taken dose; dose-derived readouts divide unit counts by it.",
+      ),
     active: z.boolean(),
     notificationsEnabled: z.boolean(),
     liveActivityEnabled: z
@@ -236,6 +245,61 @@ const medicationDetailEntry = medicationResource
       "Detail variant of the medication resource enriched with the joined `category`. The base medication fields are inlined; see the `Medication` component for their semantics.",
   });
 
+// v1.16.10 — per-container inventory entity (pen / blister pack /
+// bottle). Counts UNITS; the medication's `unitsPerDose` maps units to
+// doses. The intake consumption hook decrements `unitsRemaining` per
+// taken dose and stamps the intake event with what it consumed.
+const medicationInventoryItemResource = z
+  .object({
+    id: z.string(),
+    userId: z.string(),
+    medicationId: z.string(),
+    state: z
+      .enum(["ACTIVE", "IN_USE", "EXPIRED", "USED_UP"])
+      .describe(
+        "Container lifecycle state. ACTIVE = unopened; IN_USE = opened (30-day in-use clock running); EXPIRED = printed expiry or in-use window lapsed with units left; USED_UP = drained (terminal).",
+      ),
+    containerType: z
+      .enum(MEDICATION_CONTAINER_TYPE_VALUES)
+      .describe(
+        "Kind of physical container (PEN / AMPOULE / BLISTER / INHALER / BOTTLE / OTHER). Display-level classification; defaults to OTHER.",
+      ),
+    unitsTotal: z
+      .number()
+      .int()
+      .describe(
+        "Units the container shipped with (tablets / ampoules / puffs; 1–1000). Dose-derived readouts divide by the medication's `unitsPerDose`.",
+      ),
+    unitsRemaining: z
+      .number()
+      .int()
+      .describe(
+        "Units left in the container. Decremented by the intake consumption hook (FEFO with spillover across containers); refunded when a taken dose is skipped, edited away, or deleted.",
+      ),
+    firstUseAt: z.iso
+      .datetime({ offset: true })
+      .nullable()
+      .describe(
+        "Instant the container was first used. NULL until opened; starts the 30-day in-use clock.",
+      ),
+    expiresAt: z.iso
+      .datetime({ offset: true })
+      .nullable()
+      .describe(
+        "Persisted MIN(firstUseAt + 30 days, printedExpiry). NULL when neither clock has started.",
+      ),
+    printedExpiry: z.iso.datetime({ offset: true }).nullable(),
+    purchasedAt: z.iso.datetime({ offset: true }).nullable(),
+    notes: z.string().nullable(),
+    createdAt: z.iso.datetime({ offset: true }),
+    updatedAt: z.iso.datetime({ offset: true }),
+  })
+  .meta({
+    id: "MedicationInventoryItem",
+    description:
+      "One supply container (pen / blister pack / bottle) of a medication. Counts UNITS — the medication's `unitsPerDose` maps units to doses. The intake write paths consume from the open container first, then first-expiry-first-out over unopened stock.",
+  });
+
 const medicationIntakeEventResource = z
   .object({
     id: z.string(),
@@ -792,6 +856,135 @@ export const medicationPaths: NonNullable<ZodOpenApiObject["paths"]> = {
       },
     },
   },
+  "/api/medications/{id}/inventory": {
+    get: {
+      tags: ["Medications"],
+      summary: "List a medication's supply containers",
+      description:
+        "Returns every inventory item (all states) for the medication, ordered by state, then `expiresAt`, then `createdAt`. Items count UNITS; divide by the medication's `unitsPerDose` for dose-level figures.",
+      requestParams: {
+        path: z.object({ id: z.string() }),
+      },
+      responses: {
+        "200": {
+          description: "Inventory item list.",
+          content: {
+            "application/json": {
+              schema: dataEnvelope(
+                z.object({
+                  items: z.array(medicationInventoryItemResource),
+                  meta: z.object({ total: z.number().int().nonnegative() }),
+                }),
+                "ListMedicationInventoryResponse",
+              ),
+            },
+          },
+        },
+        "404": {
+          description: "Medication not found (or owned by another user).",
+          content: { "application/json": { schema: errorEnvelope } },
+        },
+        ...stdResponses,
+      },
+    },
+    post: {
+      tags: ["Medications"],
+      summary: "Register a new supply container",
+      description:
+        "Creates an ACTIVE inventory item with `unitsRemaining = unitsTotal`. The request's `dosesTotal` field carries UNITS (1–1000). Rate-limited 30/min/user. Audits as `medication.inventory.create`.",
+      requestParams: {
+        path: z.object({ id: z.string() }),
+      },
+      requestBody: {
+        required: true,
+        content: {
+          "application/json": { schema: createInventoryItemSchema },
+        },
+      },
+      responses: {
+        "201": {
+          description: "Created inventory item.",
+          content: {
+            "application/json": {
+              schema: dataEnvelope(
+                medicationInventoryItemResource,
+                "CreateMedicationInventoryItemResponse",
+              ),
+            },
+          },
+        },
+        "404": {
+          description: "Medication not found (or owned by another user).",
+          content: { "application/json": { schema: errorEnvelope } },
+        },
+        ...stdResponses,
+      },
+    },
+  },
+  "/api/medications/{id}/inventory/{itemId}": {
+    patch: {
+      tags: ["Medications"],
+      summary: "Mutate a supply container",
+      description:
+        "Per-item operations: manual first-use (`markAsFirstUseAt`), used-up override (`markAsUsedUp`), printed-expiry correction, absolute remaining-unit correction (`dosesRemaining`, clamped to the item's capacity), notes. The canonical state machine re-derives the state after every mutation. Audits as `medication.inventory.update`.",
+      requestParams: {
+        path: z.object({ id: z.string(), itemId: z.string() }),
+      },
+      requestBody: {
+        required: true,
+        content: {
+          "application/json": { schema: updateInventoryItemSchema },
+        },
+      },
+      responses: {
+        "200": {
+          description: "Updated inventory item.",
+          content: {
+            "application/json": {
+              schema: dataEnvelope(
+                medicationInventoryItemResource,
+                "UpdateMedicationInventoryItemResponse",
+              ),
+            },
+          },
+        },
+        "404": {
+          description:
+            "Inventory item not found (or owned by another user / medication).",
+          content: { "application/json": { schema: errorEnvelope } },
+        },
+        ...stdResponses,
+      },
+    },
+    delete: {
+      tags: ["Medications"],
+      summary: "Delete a supply container",
+      description:
+        "Hard-deletes the inventory item. The audit log captures the before-state (`medication.inventory.delete`) so a row can be reconstructed if needed. Consumption stamps on intake events that reference the item stay in place; a later restore skips the missing container.",
+      requestParams: {
+        path: z.object({ id: z.string(), itemId: z.string() }),
+      },
+      responses: {
+        "200": {
+          description: "Deletion succeeded.",
+          content: {
+            "application/json": {
+              schema: dataEnvelope(
+                z.object({ id: z.string(), deleted: z.boolean() }),
+                "DeleteMedicationInventoryItemResponse",
+              ),
+            },
+          },
+        },
+        "404": {
+          description:
+            "Inventory item not found (or owned by another user / medication).",
+          content: { "application/json": { schema: errorEnvelope } },
+        },
+        ...stdResponses,
+      },
+    },
+  },
   "/api/medications/extract": {
     post: {
       tags: ["Medications"],
diff --git a/src/lib/validations/__tests__/medication-inventory.test.ts b/src/lib/validations/__tests__/medication-inventory.test.ts
new file mode 100644
index 000000000..e29fc0399
--- /dev/null
+++ b/src/lib/validations/__tests__/medication-inventory.test.ts
@@ -0,0 +1,166 @@
+/**
+ * v1.16.10 — inventory + units-per-dose validation bounds.
+ *
+ * Pins the raised unit caps (100 → 1000 on container capacity and the
+ * stock correction; `dosesPerUnit` rides along) and the new
+ * `unitsPerDose` (1–100) and `containerType` fields. The GLP-1 legacy
+ * ledger delta deliberately KEEPS its ±100 bound — it counts pens, not
+ * units.
+ */
+import { describe, expect, it } from "vitest";
+
+import {
+  createInventoryItemSchema,
+  updateInventoryItemSchema,
+  createMedicationSchema,
+  updateMedicationSchema,
+  glp1InventoryPostSchema,
+} from "../medication";
+
+const MINIMAL_MEDICATION = {
+  name: "Med",
+  dose: "5 mg",
+  schedules: [
+    {
+      windowStart: "08:00",
+      windowEnd: "09:00",
+    },
+  ],
+};
+
+describe("createInventoryItemSchema — unit cap 1000", () => {
+  it("accepts 1000 units", () => {
+    const r = createInventoryItemSchema.safeParse({ dosesTotal: 1000 });
+    expect(r.success).toBe(true);
+  });
+
+  it("rejects 1001 units", () => {
+    const r = createInventoryItemSchema.safeParse({ dosesTotal: 1001 });
+    expect(r.success).toBe(false);
+  });
+
+  it("rejects zero", () => {
+    const r = createInventoryItemSchema.safeParse({ dosesTotal: 0 });
+    expect(r.success).toBe(false);
+  });
+
+  it("accepts every container type and defaults to absent", () => {
+    for (const ct of [
+      "PEN",
+      "AMPOULE",
+      "BLISTER",
+      "INHALER",
+      "BOTTLE",
+      "OTHER",
+    ]) {
+      const r = createInventoryItemSchema.safeParse({
+        dosesTotal: 4,
+        containerType: ct,
+      });
+      expect(r.success).toBe(true);
+    }
+    const r = createInventoryItemSchema.safeParse({ dosesTotal: 4 });
+    expect(r.success).toBe(true);
+    expect(r.success && r.data.containerType).toBeUndefined();
+  });
+
+  it("rejects an unknown container type", () => {
+    const r = createInventoryItemSchema.safeParse({
+      dosesTotal: 4,
+      containerType: "BAG",
+    });
+    expect(r.success).toBe(false);
+  });
+});
+
+describe("updateInventoryItemSchema — stock correction cap 1000", () => {
+  it("accepts 1000", () => {
+    const r = updateInventoryItemSchema.safeParse({ dosesRemaining: 1000 });
+    expect(r.success).toBe(true);
+  });
+
+  it("rejects 1001", () => {
+    const r = updateInventoryItemSchema.safeParse({ dosesRemaining: 1001 });
+    expect(r.success).toBe(false);
+  });
+});
+
+describe("medication schemas — dosesPerUnit cap 1000 + unitsPerDose 1–100", () => {
+  it("create accepts dosesPerUnit 1000 and rejects 1001", () => {
+    expect(
+      createMedicationSchema.safeParse({
+        ...MINIMAL_MEDICATION,
+        dosesPerUnit: 1000,
+      }).success,
+    ).toBe(true);
+    expect(
+      createMedicationSchema.safeParse({
+        ...MINIMAL_MEDICATION,
+        dosesPerUnit: 1001,
+      }).success,
+    ).toBe(false);
+  });
+
+  it("update accepts dosesPerUnit 1000 and rejects 1001", () => {
+    expect(updateMedicationSchema.safeParse({ dosesPerUnit: 1000 }).success).toBe(
+      true,
+    );
+    expect(updateMedicationSchema.safeParse({ dosesPerUnit: 1001 }).success).toBe(
+      false,
+    );
+  });
+
+  it("create bounds unitsPerDose to 1–100", () => {
+    expect(
+      createMedicationSchema.safeParse({
+        ...MINIMAL_MEDICATION,
+        unitsPerDose: 1,
+      }).success,
+    ).toBe(true);
+    expect(
+      createMedicationSchema.safeParse({
+        ...MINIMAL_MEDICATION,
+        unitsPerDose: 100,
+      }).success,
+    ).toBe(true);
+    expect(
+      createMedicationSchema.safeParse({
+        ...MINIMAL_MEDICATION,
+        unitsPerDose: 0,
+      }).success,
+    ).toBe(false);
+    expect(
+      createMedicationSchema.safeParse({
+        ...MINIMAL_MEDICATION,
+        unitsPerDose: 101,
+      }).success,
+    ).toBe(false);
+    expect(
+      createMedicationSchema.safeParse({
+        ...MINIMAL_MEDICATION,
+        unitsPerDose: 1.5,
+      }).success,
+    ).toBe(false);
+  });
+
+  it("update bounds unitsPerDose to 1–100", () => {
+    expect(updateMedicationSchema.safeParse({ unitsPerDose: 2 }).success).toBe(
+      true,
+    );
+    expect(updateMedicationSchema.safeParse({ unitsPerDose: 0 }).success).toBe(
+      false,
+    );
+    expect(
+      updateMedicationSchema.safeParse({ unitsPerDose: 101 }).success,
+    ).toBe(false);
+  });
+});
+
+describe("glp1InventoryPostSchema — the legacy pen-ledger delta keeps ±100", () => {
+  it("accepts ±100 and rejects ±101", () => {
+    expect(glp1InventoryPostSchema.safeParse({ delta: 100, reason: "purchased" }).success).toBe(true);
+    expect(glp1InventoryPostSchema.safeParse({ delta: -100, reason: "damaged" }).success).toBe(true);
+    expect(glp1InventoryPostSchema.safeParse({ delta: 101, reason: "purchased" }).success).toBe(false);
+    expect(glp1InventoryPostSchema.safeParse({ delta: -101, reason: "damaged" }).success).toBe(false);
+  });
+});
diff --git a/src/lib/validations/medication.ts b/src/lib/validations/medication.ts
index 1c9213675..d8ab0b5cb 100644
--- a/src/lib/validations/medication.ts
+++ b/src/lib/validations/medication.ts
@@ -456,8 +456,23 @@ export const createMedicationSchema = z
     category: z.enum(MEDICATION_CATEGORY_VALUES).optional(),
     /** v1.4.25 W4d — treatment-class discriminator (GENERIC | GLP1). */
     treatmentClass: z.enum(MEDICATION_TREATMENT_CLASS_VALUES).optional(),
-    /** v1.4.25 W4d — doses per pen/vial for inventory tracking. */
-    dosesPerUnit: z.number().int().min(1).max(100).optional(),
+    /** v1.4.25 W4d — doses per pen/vial for inventory tracking.
+     *  v1.16.10 raises the cap to 1000 (large tablet packs). */
+    dosesPerUnit: z.number().int().min(1).max(1000).optional(),
+    /**
+     * v1.16.10 — inventory units one dose consumes (2 × 2 mg tablets
+     * for a 4 mg dose). Default 1. Dose-level readouts divide the
+     * unit counts by this factor.
+     */
+    unitsPerDose: z
+      .number()
+      .int()
+      .min(1)
+      .max(100)
+      .optional()
+      .describe(
+        "Inventory units consumed per dose (e.g. 2 tablets of 2 mg for a 4 mg dose). Default 1. The intake consumption hook decrements this many units per taken dose; dose-derived readouts divide unit counts by it.",
+      ),
     /** v1.6.0 — route of administration (ORAL | INJECTION | OTHER). */
     deliveryForm: z.enum(MEDICATION_DELIVERY_FORM_VALUES).optional(),
     /**
@@ -528,7 +543,17 @@ export const updateMedicationSchema = z
     dose: z.string().min(1).max(50).optional(),
     category: z.enum(MEDICATION_CATEGORY_VALUES).optional(),
     treatmentClass: z.enum(MEDICATION_TREATMENT_CLASS_VALUES).optional(),
-    dosesPerUnit: z.number().int().min(1).max(100).nullable().optional(),
+    dosesPerUnit: z.number().int().min(1).max(1000).nullable().optional(),
+    /** v1.16.10 — inventory units one dose consumes. Default 1. */
+    unitsPerDose: z
+      .number()
+      .int()
+      .min(1)
+      .max(100)
+      .optional()
+      .describe(
+        "Inventory units consumed per dose (e.g. 2 tablets of 2 mg for a 4 mg dose). The intake consumption hook decrements this many units per taken dose; already-stamped intake events keep their recorded consumption.",
+      ),
     /** v1.6.0 — route of administration (ORAL | INJECTION | OTHER). */
     deliveryForm: z.enum(MEDICATION_DELIVERY_FORM_VALUES).optional(),
     /** v1.8.5 — per-medication injection-site tracking opt-in. */
@@ -799,41 +824,103 @@ export type BulkDeleteIntakeEventsInput = z.infer<
  * USED_UP (manual override). EXPIRED is owned by the daily cron and
  * the intake hook, so the PATCH schema deliberately omits it.
  */
-export const createInventoryItemSchema = z.object({
-  dosesTotal: z.number().int().min(1).max(100),
-  printedExpiry: z.iso
-    .datetime({ offset: true })
-    .transform((s) => new Date(s))
-    .nullable()
-    .optional(),
-  purchasedAt: z.iso
-    .datetime({ offset: true })
-    .transform((s) => new Date(s))
-    .nullable()
-    .optional(),
-  notes: z.string().max(200).nullable().optional(),
-});
+/**
+ * v1.16.10 — container kinds, mirrored from the Prisma
+ * `MedicationContainerType` enum. Display-level classification only.
+ */
+export const MEDICATION_CONTAINER_TYPE_VALUES = [
+  "PEN",
+  "AMPOULE",
+  "BLISTER",
+  "INHALER",
+  "BOTTLE",
+  "OTHER",
+] as const;
+export type MedicationContainerTypeValue =
+  (typeof MEDICATION_CONTAINER_TYPE_VALUES)[number];
 
-export const updateInventoryItemSchema = z.object({
-  markAsFirstUseAt: z.iso
-    .datetime({ offset: true })
-    .transform((s) => new Date(s))
-    .optional(),
-  markAsUsedUp: z.boolean().optional(),
-  printedExpiry: z.iso
-    .datetime({ offset: true })
-    .transform((s) => new Date(s))
-    .nullable()
-    .optional(),
-  /**
-   * v1.16.1 — stock correction (the Bestand tab's adjust / withdraw
-   * flow). Sets the remaining-dose count directly; the route clamps to
-   * `dosesTotal` and re-runs the canonical state machine (0 ⇒ USED_UP,
-   * a raise out of 0 re-evaluates against the expiry clocks).
-   */
-  dosesRemaining: z.number().int().min(0).max(100).optional(),
-  notes: z.string().max(200).nullable().optional(),
-});
+export const createInventoryItemSchema = z
+  .object({
+    /** Units the container ships with. v1.16.10 raises the cap from
+     *  100 to 1000 (large tablet packs); the wire field name stays
+     *  `dosesTotal` — it counts units, mapped to doses via
+     *  `Medication.unitsPerDose`. */
+    dosesTotal: z
+      .number()
+      .int()
+      .min(1)
+      .max(1000)
+      .describe(
+        "Units the container ships with (tablets / ampoules / puffs; 1–1000). Stored as `unitsTotal`; dose-derived readouts divide by the medication's `unitsPerDose`.",
+      ),
+    /** v1.16.10 — container kind. Defaults to OTHER when absent. */
+    containerType: z
+      .enum(MEDICATION_CONTAINER_TYPE_VALUES)
+      .optional()
+      .describe(
+        "Kind of physical container (PEN / AMPOULE / BLISTER / INHALER / BOTTLE / OTHER). Display-level only; defaults to OTHER.",
+      ),
+    printedExpiry: z.iso
+      .datetime({ offset: true })
+      .transform((s) => new Date(s))
+      .nullable()
+      .optional(),
+    purchasedAt: z.iso
+      .datetime({ offset: true })
+      .transform((s) => new Date(s))
+      .nullable()
+      .optional(),
+    notes: z.string().max(200).nullable().optional(),
+  })
+  .meta({
+    id: "CreateMedicationInventoryItemRequest",
+    description:
+      "Register a new supply container (pen / blister pack / bottle). `dosesTotal` counts UNITS (1–1000); the item starts ACTIVE with `unitsRemaining = unitsTotal` and the intake consumption hook decrements it per taken dose.",
+  });
+
+export const updateInventoryItemSchema = z
+  .object({
+    markAsFirstUseAt: z.iso
+      .datetime({ offset: true })
+      .transform((s) => new Date(s))
+      .optional()
+      .describe(
+        "Manually start the 30-day in-use clock (the user opened the container without logging an intake). ACTIVE flips to IN_USE; a backdated instant whose window already lapsed lands EXPIRED.",
+      ),
+    markAsUsedUp: z
+      .boolean()
+      .optional()
+      .describe(
+        "Terminal override: zero the remaining units and mark the container USED_UP (physically discarded).",
+      ),
+    printedExpiry: z.iso
+      .datetime({ offset: true })
+      .transform((s) => new Date(s))
+      .nullable()
+      .optional(),
+    /**
+     * v1.16.1 — stock correction (the Bestand tab's adjust / withdraw
+     * flow). Sets the remaining-unit count directly; the route clamps to
+     * `unitsTotal` and re-runs the canonical state machine (0 ⇒ USED_UP,
+     * a raise out of 0 re-evaluates against the expiry clocks).
+     * v1.16.10 raises the cap to 1000 alongside the capacity cap.
+     */
+    dosesRemaining: z
+      .number()
+      .int()
+      .min(0)
+      .max(1000)
+      .optional()
+      .describe(
+        "Absolute remaining-unit correction (0–1000). Clamped server-side to the item's `unitsTotal`; the canonical state machine re-derives the state (0 ⇒ USED_UP).",
+      ),
+    notes: z.string().max(200).nullable().optional(),
+  })
+  .meta({
+    id: "UpdateMedicationInventoryItemRequest",
+    description:
+      "Per-item inventory mutation: manual first-use, used-up override, printed-expiry correction, absolute remaining-unit correction, notes. Every field is optional and commutative.",
+  });
 
 export type CreateInventoryItemInput = z.infer<
   typeof createInventoryItemSchema
@@ -859,8 +946,9 @@ export type UpdateInventoryItemInput = z.infer<
  * - `effectiveFrom` is constrained to a ±5-year window around now —
  *   a paper-record back-fill or a planned future step both fit, but
  *   "1970" / "9999" do not.
- * - `delta` is a non-zero finite integer in [−100, 100] (the existing
- *   inventory route caps `dosesTotal` at 100 doses per pen).
+ * - `delta` is a non-zero finite integer in [−100, 100] — the legacy
+ *   ledger counts pens, and ±100 pens per correction stays plenty
+ *   (deliberately NOT raised with the v1.16.10 per-item unit cap).
  * - `reason` is a bounded string (the route logs it; raw blob bad).
  */
 const MAX_DOSE_MG = 100;