Garmin Patents Non-Invasive HbA1c Tracking for Future Watches

Garmin has filed a patent for non-invasive HbA1c estimation using optical sensors built into a wrist-worn device. This is long-term blood glucose trend tracking, not real-time monitoring during a ride or run. Think weekly or monthly averages, aimed squarely at diabetes management and metabolic health awareness.

The technology relies on optical sensors, similar in principle to the PPG hardware already used for heart rate and SpO2 on current Garmin units like the Fenix 8 or Forerunner 965. Getting accurate HbA1c readings from skin-reflected light is a significantly harder problem than pulse detection. Accuracy at clinical levels remains the core challenge that has blocked this tech from shipping on any consumer wearable so far.

Apple has been chasing non-invasive glucose monitoring for years with no product to show yet. Samsung hinted at similar ambitions with the Galaxy Watch line. Garmin filing a patent puts them in the race, but patents are not products. A 2026 timeline is plausible for a prototype feature, not a certified medical tool.

For endurance athletes, the practical use case is metabolic health monitoring between training blocks, not lap-by-lap fueling decisions. Knowing your HbA1c trend over a month of heavy training volume could flag early signs of overtraining-related metabolic stress. That is genuinely useful data if the accuracy holds up.

Patent, not product. Interesting direction from Garmin, but hold off on upgrading your Fenix until optical HbA1c actually ships and gets independently validated.