A person is shown wearing a smartwatch that displays diabetes glucose data on your wrist.
JGalione / Getty images

It is now a reality for many of us to see blood sugars with a quick glance at our wrist.

In fact, wearing a continuous glucose monitor (CGM) sensor that can beam near-real-time data to a smartwatch is becoming a cornerstone of daily care for many people with diabetes.

It is still not certain which version of the phone that the CGM is compatible with, as market leader Dexcom and others scramble to keep up with the latest consumer technology. Do-it-yourself diabetes tools are always finding new ways to use existing technology for personalized data-viewing.

Here is a look at how the currently available CGM systems from Abbott, Eversense, and others connect to the wrist, and what we can expect in the future.

We’ve come a long way since the very first diabetes wristwatch concept introduced in 2001: the GlucoWatch G2 Biographer, an early attempt at noninvasive glucose monitoring (meaning it took readings without penetrating the skin). Despite gaining regulatory approval at the time, that product unfortunately failed and was discontinued in 2007.

“There are many attempts to create a wrist-based monitor, but none have taken off. The K’Watch Glucose product has notes on it.”

“We are grateful to be able to view the readings on a mainstream watch that isn’t designed for diabetes. Apple Watch, Android Wear, and Fitbit are some of the most common models compatible with the devices.”

It is important to understand that the watch is not actually monitoring your blood sugar levels. The watch acts as a conduit for most of the technology currently available, and it simply receives the data from your sensor via a phone app.

We can credit San Diego, California-based CGM market leader Dexcom with pioneering the ability to view glucose data on a smartwatch. The company first enabled limited Apple Watch connectivity in April 2015, and later expanded that with its G5 model in March 2016, and the more advanced G6 model launched in 2018.

Image via Dexcom

The G6 mobile app is compatible with both Apple and Android watches. It shows your current number of arrows and graphs for periods of one to 24 hours.

The current data from the app on your phone is syncs with the current data on the Apple or Android watch.

We’re still waiting for Dexcom to provide direct-to-watch connectivity, which the company has been promising for years. Dexcom has said during investor updates that direct smartwatch connectivity will be coming with their next-generation G7 model, expected in the United States by the end of 2022.

Users still need to use an Apple or a Google phone to receive data and access notifications on the watch.

The Apple Watch can be used to call attention to your current reading by showing you your red, green, or yellow blood sugar level.

You can see this full list of compatible devices for the Dexcom CGM. Remember, just because a phone or watch isn’t initially listed now doesn’t mean Dexcom isn’t working to add it down the road.

One of the smartwatches compatible with the Dexcom is the Garmin watch. This development in 2021 made headlines, as it marked the first time that “real-time” CGM data could be streamed directly from Dexcom to a particular smartwatch.

Previously, this hadn’t been possible without a DIY workaround, but the Food and Drug Administration (FDA) in July 2021 gave the green light for this type of partnership to occur. It opened the door for other companies to use Dexcom’s real-time software in creating apps or other wearable options for data display as well.

This was the first time that a company outside of Dexcom was able to use the real-time software to develop and integrate their own apps and devices.

They even made a polished 74-second commercial highlighting the development, featuring some high profile celeb athletes who live with diabetes themselves.

“You can see real-time diabetes levels, a trend arrow and a 3-hour history on a compatible Garmin watch with the ‘Connect IQ’ widget.”

Users can see the data on a compatible bike computer while working with it. It displays a number of performance metrics, including trend direction, and the level of blood sugar.

One benefit of this is that you can review your data later on, in order to see how your blood sugar levels changed during an exercise event like a run or bike ride. That is very beneficial in understanding the effect of exercise on our blood sugars.

“Even though you can get real-time data on the trends on these devices, and watch them, you won’t get any of the alarms or alerts that are included by Garmin.”

The Connect IQ widget is being used to communicate with other mobile apps and data platforms. The notifications from the other app will be active, which means that the device will receive them.

While using the newest version of the Connect IQ app, a senior media relations specialist for fitness at Garmin was still able to get notifications from the company.

This also does not include any functionality for Dexcom Followers — those who are not wearing the Dexcom G6 themselves, but are remotely monitoring a child or other person’s CGM data through the Dexcom mobile app. While Garmin and Dexcom are both aware that is of interest for many in the D-Community, it is not yet possible.

Jake Leach, the chief technology officer of the company, said that the addition of the devices to the platform will make it easier for users to view and monitor their blood sugar levels. The first partner to connect to the new real-time platform is garmin, who will showcase the value of integrated CGM and further solidify the position of the most powerful and connected CGM in the world.

Medtronic Diabetes is the market leader in insulin pumps and the only company that also makes a CGM, the Guardian Connect. For the most part, they are pushing customers to purchase their combined system, the partially automated Medtronic 770G.

“The company’s tech doesn’t have a real-time data display on Apple or Android watches. The data on the Guardian Connect CGM can be accessed on the mobile app of the company, but only if you use it as a stand-alone product.”

The company told DiabetesMine that it is no longer working on a watch device, but that it had been collaborating with the company.

The implantable Eversense CGM from Senseonics and Ascensia Diabetes Care is unique in that it does not have its own receiver, but is completely dependent on a smartphone app to function. That means to activate the system, see glucose readings, and receive alerts for high and low blood sugars, you need to use a smartphone.

The company website says Eversense is compatible with both the Apple Watch and the other mobile devices. There is no timetable on when the smartwatch connection will be available.

See the full compatibility list here for more details on which devices work with the Eversense CGM.

This system from Abbott Diabetes Care is known as a “Flash Glucose Monitor” that requires users to manually wave a scanner over the small circular sensor worn on the arm to get a glucose reading. That is true for the FreeStyle Libre 2 model, but the new version 3 recently launched outside the United States is doing away with the need for manual scanning, making it more competitive with CGMs from Dexcom, Medtronic, and even the implantable Eversense.

In Europe, several DIY tools have emerged that make smartwatch connectivity possible for the FreeStyle Libre, but it’s not yet available through the commercial models that need to be scanned in order to display glucose results.

It is possible that Abbott will offer that when the Libre 3 arrives in the United States.

Around 2013, tech-savvy developers and coders began hacking into their diabetes devices and building mobile apps to beam data onto smartphones and watches. This became known as the #WeAreNotWaiting DIY diabetes movement.

The mobile apps they created for data-sharing, including Nightscout and xDrip, actually paved the way for smartwatches and remote connectivity for CGMs.

It began with the popular Pebble Watch, which was acquired by Fitbit. There is now a handful of new Fitbit smartwatches that weave in CGM connectivity, including the Fitbit Versa and Ionic brands.

Many developers are trying to create a successful watch that tracks the sugar levels in the blood.

Notable among those is the K’Watch Glucose tracking watch launched in 2018, a year after first grabbing headlines at the big Consumer Electronics Show (CES) in Las Vegas, Nevada. This doesn’t continuously monitor glucose, but takes a measurement every time you touch a button on the watch to prompt it to do so.

K’Watch is the creation of the 2016-formed French startup company PKVitality (pronounced PEEKA-Vitality), which brands it as “the first-ever glucose monitoring sensor embedded directly into a wearable device that measures blood glucose levels through your skin.” [Guess they never heard of the now-defunct GlucoWatch?]

“The company states that the watch uses micro needles to taste fluid just below the skin’s surface and analyze it for sugars.”

The watch face has a special biosensor that can painlessly penetrate the top layer of skin and analyze the fluid in it.