diff --git a/src/app/api/auth/me/glucose-unit/route.ts b/src/app/api/auth/me/glucose-unit/route.ts
index 719d3f45a..cd315578a 100644
--- a/src/app/api/auth/me/glucose-unit/route.ts
+++ b/src/app/api/auth/me/glucose-unit/route.ts
@@ -34,6 +34,7 @@ import { checkRateLimit, rateLimitHeaders } from "@/lib/rate-limit";
 import { resolveGlucoseUnit, type GlucoseUnit } from "@/lib/glucose";
 import { glucoseUnitPatchSchema } from "@/lib/validations/user-prefs";
 import { refreshTextsAfterUnitChange } from "@/lib/insights/unit-change-refresh";
+import { invalidateUserProfile } from "@/lib/cache/invalidate";
 
 export const dynamic = "force-dynamic";
 
@@ -103,9 +104,11 @@ export const PATCH = apiHandler(async (req: Request) => {
     },
   });
 
-  // The status notes and narratives quote glucose in this unit; re-warm
-  // them so today's stored text does not keep the old one.
+  // The targets payload and the status notes and narratives carry glucose in
+  // this unit: evict the cached payloads and re-warm today's stored text so
+  // neither keeps the old one.
   if (resolveGlucoseUnit(previous?.glucoseUnit) !== next) {
+    invalidateUserProfile(user.id);
     void refreshTextsAfterUnitChange(user.id);
   }
 
diff --git a/src/components/settings/__tests__/glucose-unit-select.test.tsx b/src/components/settings/__tests__/glucose-unit-select.test.tsx
index 8893020e8..49584a291 100644
--- a/src/components/settings/__tests__/glucose-unit-select.test.tsx
+++ b/src/components/settings/__tests__/glucose-unit-select.test.tsx
@@ -134,6 +134,19 @@ describe("Settings — GlucoseUnitSelect", () => {
     expect(componentSource).toMatch(/queryKey: queryKeys\.authMe\(\)/);
   });
 
+  // The targets panel takes its unit from the targets payload, not from the
+  // account, so a save that only refreshed `/me` left it on the old unit
+  // until the server cache turned over (up to ten minutes). Both ends have
+  // to let go of the old payload.
+  it("refreshes the targets payload on both ends", () => {
+    expect(componentSource).toMatch(/queryKey: queryKeys\.insightsTargets\(\)/);
+    const route = readFileSync(
+      join(process.cwd(), "src/app/api/auth/me/glucose-unit/route.ts"),
+      "utf8",
+    );
+    expect(route).toMatch(/!== next\) \{\s*invalidateUserProfile\(user\.id\);/);
+  });
+
   it("is actually mounted on the settings page", () => {
     // A control nobody can reach is the same defect as no control.
     const accountSection = readFileSync(
diff --git a/src/components/settings/glucose-unit-select.tsx b/src/components/settings/glucose-unit-select.tsx
index 234ec0434..e98274c0b 100644
--- a/src/components/settings/glucose-unit-select.tsx
+++ b/src/components/settings/glucose-unit-select.tsx
@@ -31,7 +31,8 @@ import { resolveGlucoseUnit, type GlucoseUnit } from "@/lib/glucose";
  * Persistence mirrors the unit-system select: a change PATCHes
  * `/api/auth/me/glucose-unit` immediately and invalidates `queryKeys.authMe()`,
  * so the dashboard tiles and the glucose insight page re-render on the next
- * /me refetch.
+ * /me refetch, and `queryKeys.insightsTargets()`, whose payload states the
+ * target ranges in the unit it was built with.
  */
 export function GlucoseUnitSelect({
   isAuthenticated,
@@ -66,6 +67,7 @@ export function GlucoseUnitSelect({
     onSuccess: () => {
       toastWrittenOutcome("success", t("settings.dashboard.glucoseUnit.saved"));
       queryClient.invalidateQueries({ queryKey: queryKeys.authMe() });
+      queryClient.invalidateQueries({ queryKey: queryKeys.insightsTargets() });
       setOptimistic(null);
     },
     onError: (err) => {
diff --git a/src/lib/cache/invalidate.ts b/src/lib/cache/invalidate.ts
index 0081f1eea..4df20d5a0 100644
--- a/src/lib/cache/invalidate.ts
+++ b/src/lib/cache/invalidate.ts
@@ -242,10 +242,11 @@ export function invalidateUserHealthScore(userId: string): void {
  * on the very next read.
  *
  * Callers: `/api/user/thresholds` PUT + DELETE, `applyProfileUpdate`
- * (only when heightCm / dateOfBirth / gender is in the update set), and
- * `/api/auth/me/source-priority` PUT. The unit-preference toggle is NOT
- * wired in: it only drives the client-side display transform, no
- * server-cached payload reads it.
+ * (only when heightCm / dateOfBirth / gender is in the update set),
+ * `/api/auth/me/source-priority` PUT, and `/api/auth/me/glucose-unit` PATCH
+ * (the targets payload states glucose in the account's unit). The
+ * unit-preference toggle is NOT wired in: it only drives the client-side
+ * display transform, no server-cached payload reads it.
  */
 export function invalidateUserProfile(userId: string): void {
   caches.insightsTargets.deleteByPrefix(userId);