Feb 22: The US Food and Drug Administration issued a warning about the risks of using smartwatches and smart rings that claim to measure blood glucose levels without piercing the skin.

The FDA notes that it has not authorized or approved any smartwatch or smart ring that is intended to measure blood glucose levels on its own. The use of these devices can lead to inaccurate measurements of blood glucose, also known as blood sugar, and errors in diabetes management that can be life-threatening, the agency warned.

“If your medical care depends on accurate blood glucose measurements, talk to your health care provider about an appropriate FDA-authorized device for your needs,” the FDA said in a statement.

These unauthorized devices are different from smartwatch apps that display data from FDA-approved continuous glucose monitoring devices that pierce the skin.

The FDA did not name specific brands but said the sellers of these unauthorized smartwatches and smart rings advertise using “non-invasive techniques” to measure blood glucose without requiring people to prick their fingers or pierce their skin. However, these devices do not directly test blood glucose levels, the agency said, urging consumers to avoid buying them for that purpose.

The agency also advised healthcare providers to discuss the risk of using unauthorized blood glucose measuring devices with their patients and to help them select an appropriate authorized device for their needs.

“The agency is working to ensure that manufacturers, distributors, and sellers do not illegally market unauthorized smartwatches or smart rings that claim to measure blood glucose levels,” the FDA said in the statement.

Consumers can report any adverse events or problems with inaccurate blood glucose measurement from using unauthorized smartwatches or smart rings through the FDA MedWatch Voluntary Reporting Form.