n 2024 the FDA cleared the first over-the-counter continuous glucose monitors — a sensor on your arm, a graph on your phone, no prescription. The wellness internet immediately decided everyone needs one forever. The evidence says something smaller and more useful: a few weeks of glucose data can teach you real things, most of them once, and the diagnostic test it does not replace costs $15.
Be precise about who the OTC clearance covers: adults 18 and older who do not use insulin. These sensors are explicitly not cleared for insulin dosing decisions — that remains prescription-CGM territory, managed with a clinician. If you have diabetes on insulin, this guide is not your lane; the OTC products themselves say so.
What the sensor actually shows you
A CGM samples interstitial glucose around the clock, so you see the shape of your response to real life: which meals spike you and which don't, what a walk after dinner does to the curve, what bad sleep does to the next morning. For prediabetes — which most people who have it don't know they have — watching the curve respond to food choices is concrete in a way a yearly lab number isn't. That feedback loop is the legitimate product.
It's also mostly a two-to-four-week product. The lessons repeat: your body's big responses are consistent, and after a month you've met them. The subscription model wants you sensored year-round at $50–100 a month; unless you're actively managing a diagnosis with your clinician, the marginal insight of month six is close to zero. Run an experiment, learn your patterns, stop.
The $15 test it doesn't replace
Diabetes and prediabetes are diagnosed with lab tests — A1c, fasting glucose, oral tolerance — interpreted by a clinician. A CGM trace is not a diagnosis, and a normal-looking week doesn't clear you. A hemoglobin A1c is one of the cheapest cash labs in Austin (live price below); if you're worried enough about glucose to buy a sensor, the lab draw is the higher-information dollar and the place to start.
OTC CGMs and the rest of our disclosed direct-to-consumer device shortlist, with who each is actually for, on one page.
See the devices shelf →- Do I need a prescription for a CGM?
- Not anymore, for the OTC category: since 2024 the FDA has cleared over-the-counter CGMs for adults 18+ who don't use insulin. Insulin users still need prescription CGM systems managed with a clinician.
- Can a CGM diagnose diabetes or prediabetes?
- No. Diagnosis uses lab tests — A1c, fasting glucose, or an oral glucose tolerance test — interpreted by a clinician. An A1c is one of the cheapest cash labs in Austin and is the right first step if you're concerned.
- Is a CGM worth it if I'm healthy?
- As a short experiment, maybe — a few weeks of data shows how your meals, movement, and sleep move your glucose, and those lessons mostly repeat after that. There's no outcome evidence that long-term CGM use benefits healthy people, so the ongoing subscription is hard to justify.