No Apple Watch can measure blood sugar on its own. There is no built-in sensor for blood glucose in any model, including the latest Series 10 and Ultra 2. To see blood sugar readings on your Apple Watch, you need a separate glucose monitoring device that sends data to the watch through an app. Several options exist depending on whether you use a continuous glucose monitor (CGM) or a traditional fingerstick meter.
Why Apple Watch Can’t Measure Blood Sugar Directly
Apple has been working on non-invasive glucose monitoring technology for years. The project reportedly uses a chip-based system called silicon photonics paired with optical absorption spectroscopy. In theory, lasers emit specific wavelengths of light into the skin, where interstitial fluid absorbs glucose. The reflected light indicates glucose concentration, and an algorithm calculates a reading. But this technology has not made it into any shipping product.
The FDA issued a safety communication in February 2024 explicitly warning consumers not to buy or use smartwatches or smart rings that claim to measure blood glucose without piercing the skin. The agency has not authorized, cleared, or approved any smartwatch or smart ring for standalone glucose measurement. If you see a third-party watch or app claiming it can read your blood sugar through the Apple Watch’s sensors alone, avoid it.
Using a Dexcom G7 With Apple Watch
The Dexcom G7 continuous glucose monitor offers a “Direct to Watch” feature that sends real-time glucose readings straight to your Apple Watch, even without your iPhone nearby. This is the most seamless CGM-to-watch experience currently available. To use it, you need:
- Apple Watch Series 6 or later, running watchOS 10 or later
- An iPhone running iOS 17 or later
- Dexcom G7 app version 2.2.1 or later
Once set up, the Dexcom app displays your current glucose reading, trend arrows showing whether your levels are rising or falling, and your recent history. You can also add a Dexcom complication to your watch face so your glucose number is visible at a glance without opening the app.
Using a FreeStyle Libre on Apple Watch
Abbott’s FreeStyle Libre system works with Apple Watch through its Libre watch app. The app displays glucose readings from Libre 2 and Libre 3 sensors, pulling data through the LibreLinkUp cloud. You can add a complication to your watch face that shows your current reading without opening the full app. When a reading is out of the sensor’s measurable range, the complication displays “Hi” or “LO” instead of a number.
One thing to know: the watch complication doesn’t refresh on a fixed schedule. WatchOS controls how often it updates to preserve battery life, so there can be a slight delay between your sensor reading and what appears on your wrist. Abbott also notes that the Libre watch app should not be used to make treatment decisions. Your smartphone app remains the primary interface.
Third-party apps like FLwatch offer an alternative way to view FreeStyle Libre data on Apple Watch, also using the LibreLinkUp cloud to pull readings from Libre 2 and Libre 3 sensors.
Logging Blood Sugar From a Fingerstick Meter
If you use a traditional blood glucose meter instead of a CGM, your options are more limited but still functional. The One Drop Chrome meter connects to Apple Watch via Bluetooth and sends fingerstick readings directly to the watch, letting you see glucose levels and trends without needing your phone nearby.
Apps like mySugr can display glucose values on Apple Watch, though the manual logging of readings typically happens on the iPhone app rather than directly on the watch. The watch side serves more as a display for data already entered or received from connected devices.
How to Add a Glucose Complication to Your Watch Face
Once you have a glucose app installed on your Apple Watch, you can pin your reading to your watch face as a complication. This puts your latest blood sugar number right where you can see it every time you raise your wrist.
To set it up: with your watch face showing, touch and hold the display, then tap Edit. Swipe left until you reach the last screen, which shows available complication slots. Tap the slot where you want your glucose reading to appear, then turn the Digital Crown to scroll through available options until you find your glucose app. Press the Digital Crown to save, then tap the face to switch to it.
Not every watch face supports the same number or style of complications. Faces like Modular, Infograph, and California offer multiple slots, while simpler faces may have just one or two.
How Blood Sugar Data Works in Apple Health
All glucose data from CGMs, meters, and manual entries can flow into the Apple Health app on your iPhone. Health stores blood glucose samples in either mg/dL or mmol/L depending on your region, and you can change your preferred unit in the app’s settings. This creates a central record that your doctor can review, and it lets you spot patterns across days or weeks alongside other health metrics like activity, sleep, and heart rate.
You can also enter blood sugar readings manually in the Health app if you want to keep a log without a connected device. Open Health, tap Browse, search for Blood Glucose, and use the “Add Data” option to type in a reading.