Smart Rings and Watches cannot measure blood glucose: FDA Issues Stark Warning

In an unusual step, the US FDA has warned consumers not to trust any blood glucose estimate from smart rings or smartwatches. It further states that it has never approved any smart rings or smart watches for that purpose. Clearly, the FDA is concerned about consumers making dangerously incorrect medical decisions based on flakey technology.

Do not buy or use smartwatches or smart rings that claim to measure blood glucose levels. These devices may be sold through online marketplaces or directly from the seller. [FDA]

The only option currently open for consumers to safely buy and use blood glucose tools that correctly monitor levels is from invasive patches such as those from DEXCOM and ABBOTT. The sportier people regularly reading this blog will perhaps have come across Supersapiens who use the ABBOT Libre sensor, which is a valid device. Indeed, Supersapiens is launching in the USA very shortly and pivoting its approach also to target diabetes sufferers as well as sports people.

Wearables that claim to measure blood glucose levels non-invasively (but probably not accurately) include:

• Glucose Sport – Attaches a sensor to the forearm that collects and analyzes interstitial fluid through the skin to estimate glucose levels. Requires daily calibration via fingerstick.
• QardioGlucose – Wrist-worn device that uses optical sensors to detect changes in tissue optics related to glucose levels. Still in the development stage.
• EverlyWell Prédiabetes Risk Assessment Tracker – Wrist-worn optical sensor estimates the risk of prediabetes/diabetes based on temperature, heart rate and other biometrics.
• Biowave COR – A patch that sticks to the upper arm and uses dielectric spectroscopy to detect glucose-related changes in fluid beneath the skin.
• Empatica Embrace & Embrace 2 – Watches that analyze subtle changes in heart rate, skin temperature, blood flow and galvanic skin response over time to track glucose trends.
• Aiva Diabetes Prevention Smart Bracelet – Tracks activity, heart rate variability and skin temperature to estimate diabetes risk progression.

These should not be confused with companies like Oura. It should be noted that Oura does NOT claim to measure blood glucose but rather integrates with companies that do measure it (DEXCOM/ABBOTT). The same can be said of Garmin and Apple (DEXCOM/ABBOTT/SUPERSAPIENS).

That said, many tech companies are looking at new methods for obtaining blood glucose measurements non-invasively. The first company that can do that AND get FDA approval will make rather a lot of money. The name of Rockley Photonics often crops up in this discussion and the likes of Apple Watch may well use such technologies within a few years.

Suspicion

I suspect that the FDA is concerned that some companies are being a trifle vague in describing how their products estimate blood glucose.

It is probably also pre-empting moves that we will likely see this year or next as the first commercially available, non-invasive blood glucose sensors hit the market. The FDA is drawing a line in the sand that these devices need approval before companies start to make vague and perhaps spurious claims.