Levels
Continuous glucose monitoring + AI insights — turning blood sugar into a daily metric.
The CGM-as-a-service that turned blood sugar from a diabetic metric into a longevity metric.
Levels deserves credit for inventing a category. Pre-Levels, continuous glucose monitors were prescribed for type-2 diabetics and almost nobody else used them. Post-Levels, half of longevity Twitter has worn one for at least a month.
The product is a software layer on top of off-the-shelf CGM hardware (Stelo or Dexcom). The value-add is the app: meal photo logging, glucose-response scoring, sleep + exercise correlation, and an AI coach that explains why your bagel spiked you to 180 mg/dL when your oatmeal didn't.
Who should actually wear one: people optimizing insulin sensitivity, anyone with prediabetes signals, athletes managing fueling, anyone curious about their personal food responses. Who shouldn't: people who'll obsess over normal variation. Glucose moves a lot in healthy people; the app contextualizes it but you have to be ready to learn what "normal" looks like.
Anyone wanting to understand their personal food/exercise/sleep response to glucose, or working on insulin sensitivity.
You're prone to obsessing over normal variation, or you already have well-managed metabolic health and don't need data.