The U.S. Food and Drug Administration (FDA) has issued a clear warning against using smartwatches and rings to measure blood sugar. The agency notes that these devices rely on algorithmic calculations that diverge from the measurements displayed by medical instruments, and this distinction matters for user safety.
The FDA also stresses that noninvasive wearables should not be mistaken for continuous glucose monitoring (CGM) systems. CGMs are FDA-approved and can connect with smartphones and smartwatches through dedicated apps. CGMs involve a tiny sensor placed under the skin to monitor glucose in the interstitial fluid, providing clinically validated data for diabetes management.
Manufacturers of smart watches and rings contend that some devices can estimate blood sugar by analyzing optical or electrical signals. The FDA, however, cautions that these estimates can be inaccurate or inconsistent. Relying on them could lead diabetics to take incorrect insulin doses or other medications, heightening the risk of dangerous swings in blood sugar such as hypoglycemia or hyperglycemia.
There are ongoing efforts in the tech sector to expand noninvasive glucose sensing. Reports indicate an American company developing a watch that would use laser spectroscopy to analyze blood. Samsung has publicly explored the use of optical sensors for glucose monitoring. In 2023, Huawei released the Huawei Watch 4, which included a noninvasive glucose measurement feature but limited its availability to the Chinese market. These developments illustrate the industry’s interest in noninvasive approaches, even as regulatory bodies emphasize caution and rigorous validation (FDA, 2024).
Earlier comments about the latest smartwatches highlighted issues with screen performance and reliability, underscoring that device accuracy is a broader concern across consumer wearables. The safety-relevant implications of glucose measurement in consumer devices remain a central point for health professionals, patients, and regulators alike (FDA, 2024).
In practice, users should treat noninvasive wearables as educational tools rather than medical devices for glucose management. For clinical decisions, established CGMs or finger-prick tests remain the standard of care. Consumers looking at wellness devices should consult healthcare providers to understand the limits of these technologies and avoid substituting medical-grade measurements with consumer-level estimates. This cautious approach helps prevent dangerous misinterpretations that could affect treatment plans and overall health outcomes (FDA, 2024).