According to the US Food and Drug Administration (FDA), smartwatches that claim to non-invasively measure blood sugar cannot directly measure glucose levels.
The agency is advising people to avoid devices that claim to do this, and further states that such devices that do are illegally marketed.
In a statement the agency says: “The FDA has not authorised, cleared, or approved any smartwatch or smart ring that is intended to measure or estimate blood glucose values on its own.”
The agency was keen to differentiate approved products that use sensors to pierce the skin. Continuous glucose monitors (CGMs) such as Abbott’s Freestyle Libre and Dexcom’s G6 are regulated by the FDA and reliably measure blood sugar levels.