No smartwatch currently measures blood glucose on its own. Despite marketing claims from some cheap devices sold online, no watch can accurately read your blood sugar through your skin without a sensor. What does exist, and what’s genuinely useful, is a growing ecosystem of smartwatches that display real-time glucose data from a separate continuous glucose monitor (CGM) worn on your body. For many people with diabetes, this setup has become a practical, glanceable way to track glucose throughout the day.
How Smartwatches Actually Work With Glucose Data
A smartwatch in diabetes management acts as a display, not a sensor. It receives glucose readings from a CGM sensor (a small device typically worn on the back of your arm or abdomen) and shows your current number, a trend arrow indicating direction, and a graph of recent readings. The data reaches your watch either through your phone or, in some newer setups, directly from the sensor itself.
This means the core investment isn’t the watch. It’s the CGM system. The two major players are Dexcom and Abbott’s FreeStyle Libre, and both now offer ways to push data to popular smartwatch platforms.
Dexcom G7: The Most Watch-Friendly CGM
Dexcom’s G7 currently offers the best direct smartwatch integration. Its standout feature is direct-to-watch connectivity, meaning the sensor sends glucose data straight to your Apple Watch without needing your iPhone nearby. This is particularly useful during exercise, sleep, or any time you’d rather leave your phone behind.
Direct-to-watch works with Apple Watch Series 6 and newer (including both Ultra models and the second-generation SE), running watchOS 10 or later. You can see your current glucose reading, a trend arrow, and graphs covering 1-hour, 3-hour, 6-hour, and 24-hour windows.
Dexcom also integrates with Garmin watches through a Connect IQ widget, which was notable when it launched in 2021 as the first real-time CGM streaming to a sports watch. The Garmin integration shows glucose levels, trend arrows, and a 3-hour history line. For athletes and active users, there’s also a data field that overlays glucose readings alongside performance metrics like heart rate and pace during workouts. One limitation: Garmin doesn’t generate its own high or low glucose alarms. It relies on forwarding notifications from the Dexcom app on your phone, so you’ll need your phone within Bluetooth range to receive alerts.
FreeStyle Libre 3 on Apple Watch
Abbott’s FreeStyle Libre 3 system works with Apple Watch through the Libre app. The setup mirrors notifications and glucose readings from your phone to the watch face. The key difference from Dexcom’s approach is that the Libre system requires your smartphone to stay within range of both the sensor and the watch. There’s no direct sensor-to-watch connection. Your phone acts as the middleman, so if you leave it in another room, your watch won’t update.
Abbott offers video guides for setting up and viewing readings on Apple Watch, but compatibility is limited to certain watch models and operating system versions.
Third-Party Apps Expand Your Options
Beyond the official manufacturer apps, a thriving ecosystem of third-party software gives you more flexibility in how and where you see your glucose data. Nightscout, an open-source platform originally built by parents of children with Type 1 diabetes, can push glucose readings to nearly every major smartwatch platform.
The options break down by watch type:
- Apple Watch: Loop, Nightscout App, and Sugarmate all display blood glucose readings, trend arrows, and (for Loop users) automated insulin delivery status.
- Wear OS (Google): xDrip+ and Nightwatch provide glucose display, trend arrows, and notifications.
- Samsung Galaxy Watch: xDrip+ and Nightwatch work here as well, with full trend and notification support.
- Garmin: Nightscout Connect displays glucose and trend arrows.
- Fitbit: Glance offers basic glucose display and trend arrows.
These third-party tools are especially valuable if you use a CGM that doesn’t have its own native watch app, or if you prefer a watch brand that isn’t officially supported by your CGM manufacturer. Setup requires some technical comfort, particularly with Nightscout, but online communities offer detailed walkthroughs.
Watches That Claim to Measure Glucose: A Real Danger
If you’ve seen cheap smartwatches on Amazon or other retailers advertising “blood glucose monitoring” as a built-in feature, avoid them. In February 2024, the FDA issued a safety communication explicitly warning consumers not to use smartwatches or smart rings that claim to measure blood glucose levels without piercing the skin.
The reason this matters so much for people with diabetes is that inaccurate readings lead to dangerous medication decisions. If a watch tells you your glucose is high when it isn’t, you might take insulin you don’t need. The FDA warned that taking too much of certain diabetes medications based on a false reading can cause blood sugar to crash low enough to cause confusion, coma, or death within hours. No smartwatch or smart ring on the market has received FDA clearance to measure glucose levels noninvasively.
Choosing the Right Watch for Your Setup
Your best smartwatch choice depends on which CGM you use and what matters most to you in daily life.
If you want the most seamless, phone-free glucose monitoring, the combination of a Dexcom G7 with an Apple Watch Series 6 or newer is currently the strongest option. Direct-to-watch connectivity means fewer points of failure and more independence from your phone.
If you’re a runner, cyclist, or outdoor athlete who already uses Garmin, the Dexcom Connect IQ integration lets you see glucose data mid-workout alongside your other fitness metrics. Just keep in mind you’ll need your phone for alerts.
If you use the FreeStyle Libre 3, an Apple Watch will display your readings, but plan on keeping your phone close. For Samsung Galaxy Watch and Wear OS users, third-party apps like xDrip+ fill the gap when official apps aren’t available for your platform.
The technology is genuinely useful right now, even without a watch that measures glucose independently. Being able to glance at your wrist and see your current number, whether it’s rising or falling, and how the last few hours have trended is a meaningful quality-of-life improvement over pulling out your phone every time you want to check.