FDA warns against smartwatches and rings that claim to measure blood sugar without needles

Smartwatches and rings that claim to measure blood sugar levels for medical purposes without piercing the skin could be dangerous and should be avoided, the U.S. Food and Drug Administration warned Wednesday.

The caution applies to any watch or ring, regardless of brand, that claims to measure blood glucose levels in a noninvasive way, the agency said. The FDA said it has not authorized any such device.

The agency’s notice doesn’t apply to smartwatch apps linked to sensors, such as continuous glucose monitoring systems that measure blood sugar directly.

Roughly 37 million Americans have diabetes. People with the disease aren’t able to effectively regulate their blood sugar because their bodies either don’t make enough of the hormone insulin or they have become resistant to insulin.

To manage the condition, they must regularly check their blood sugar levels with a finger prick blood test or with a sensor that places needles just under the skin to monitor glucose levels continuously.

Using the unapproved smartwatch and smart ring devices could result in inaccurate blood sugar measurements, with “potentially devastating” consequences, said Dr. Robert Gabbay, of the American Diabetes Association. That could cause patients to take the wrong doses of medication, leading to dangerous levels of blood sugar and possibly mental confusion, coma or even death.