The Food and Drug Administration (FDA) has issued a warning to Americans: “Do not use smartwatches or smart rings to measure blood glucose levels.”
Many people in the diabetes community have undoubtedly been tempted by noninvasive blood sugar meters and monitors in the form of rings and watches, which can easily be found at Amazon and other online vendors. A noninvasive glucose monitor is a device that can measure blood sugar levels without piercing the skin. They promise a needle-free experience, and may cost far less than leading continuous glucose monitor (CGM) systems.
But the FDA wants consumers to know that none of these products have ever been evaluated for accuracy by authorities: “The FDA has not authorized, cleared, or approved any smartwatch or smart ring that is intended to measure or estimate blood glucose values on its own.”
Glucose-monitoring watches or rings, in other words, cannot be trusted. The manufacturers of the available models have not bothered to submit their devices for FDA testing. These devices are not medical equipment, and the glucose values they report should be considered inaccurate (if not fictional). The FDA is emphasizing that they should absolutely not be used for diabetes management decisions.
While inaccurate blood sugar values may be relatively harmless for people without diabetes, they can be extraordinarily dangerous to people who use insulin, sulfonylureas, or any other medication that carries a risk of hypoglycemia (low blood sugar). Basing a treatment decision (for example, the decision to administer insulin to bring a high blood sugar level down) on an inaccurate measurement could be disastrous.
Will We Ever Have Approved Noninvasive Glucose Monitors?
A reliable noninvasive glucose monitor is routinely described as one of the holy grails of diabetes tech.
For years, the diabetes community has been delighted by rumors that companies such as Apple, Google, and Samsung were adding glucose measurement to their smartwatches or developing standalone glucose monitoring devices.
About a decade ago, Apple CEO Tim Cook explained that the tech giant had no interest in registering their signature watch as a true medical device, but left the door open regarding a specialized product: “We don’t want to put the watch through the FDA process. I wouldn’t mind putting something adjacent to the watch through it, but not the watch because it would hold us back from innovating too much, the cycles are too long.”
The rumors are still swirling, but as yet none of these tech giants have released a product capable of blood sugar measuring. The Oura Smart Ring, a trendsetting biohacking device, cannot measure blood sugar either, though it can integrate CGM data into its reporting.
It’s not just the big guys racing to develop a noninvasive CGM. We recently profiled Know Labs, a start-up that intends to submit its latest prototype for full FDA approval. If successful, there could be a noninvasive CGM on the market as early as the end of 2025.
As of this writing, the noninvasive glucose meters and monitors available for purchase in the United States appear to mostly come from smaller and more obscure businesses — ones that are presumably less capable of (and dedicated to) quality engineering. The FDA states: “These smartwatches and smart rings are manufactured by dozens of companies and sold under multiple brand names.”