The Luna Smart Ring is a lightweight health tracker worn on the finger. It uses multi-sensor data to log sleep, heart rate, stress, blood oxygen, activity and menstrual cycles, and an AI assistant turns that into a personalized report and guidance. At 2mm thin and 2.5g it is easy to wear overnight, which is where most of its value sits. Against rivals like Oura and Ultrahuman it covers the same core metrics and adds an AI report, but it has no established track record and its sizing follows its own standard, so fit is the main risk.
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Ratings are high but thin, with 19 scores averaging 4.8. Buyers mostly praise comfort and the low-profile fit for sleep and workouts.
The Luna Smart Ring is a wearable health tracker in ring form. Its multi-sensor design continuously tracks sleep, heart rate, stress levels, blood oxygen, physical activity and menstrual cycles. A built-in AI assistant provides a personalized report and guidance on wellness and daily habits.
The ring has a super-thin 2mm profile and weighs 2.5g. It is designed to stay out of the way during workouts, running, diving and other physical activity, as well as during sleep and work. It is rated IP68. The ring uses its own sizing standard, which differs from standard ring sizes, so size it before buying.
