The OTC continuous glucose monitoring market hit $370 million in 2024 and is projected to grow at nearly 17% annually through 2034. Dexcom launched Stelo, the first prescription-free glucose biosensor in the U.S., priced at $89–99 a month. Abbott followed with Lingo, a device explicitly marketed to non-diabetic wellness consumers. Somewhere, a biohacker is narrating a reel about their glucose curve after eating a banana.
This is the fitness industry at its most seductive. A real medical device, a real number on your phone, a real sense that you are doing something. The question nobody is asking loudly enough: does any of this actually change what you eat, how you move, or how long you live, if you don't have diabetes?
The honest answer is: probably a little, temporarily, for some people, under specific conditions. That is not the pitch you are seeing on Instagram.
What the Research Actually Says
Researchers from Mass General Brigham published a finding that should be on the box of every OTC CGM sold to healthy adults. They analyzed CGM data from people with diabetes, prediabetes, and normal glucose control and found that while CGM readings tracked reliably with standard HbA1c tests in people with diabetes, that relationship disappeared entirely in people without diabetes. The numbers you're watching spike after your morning oats may not be telling you anything medically meaningful at all.
A 2025 systematic review covering studies published through August 2025 found that direct evidence of CGM changing hard cardiovascular outcomes in non-diabetic people is limited. The reviewers concluded that future trials need to evaluate whether CGM-guided behavioral interventions are "cost-effective and sustainable" before recommending them broadly. That is academic language for: we do not know yet.
A separate 2025 meta-analysis covering 21 trials with 1,488 adults found that CGM can reduce carbohydrate intake and shift dietary patterns. But it found insufficient evidence that CGM promotes more physical activity. Read that contrast carefully: the device may nudge you to swap white rice for quinoa, but it probably won't get you off the couch.
There are genuinely interesting pilot findings. One study of healthy participants over a month found glucose improvements and behavior changes in about half the participants, with people adjusting meal timing based on readings. But the same study noted that some participants simply ignored glucose spikes because they felt no symptoms, which researchers called "behavioral inertia." Half the people in a motivated research study shrugged at the data. That is not a behavioral revolution.
The Levels blog, which sells a CGM-based wellness program, puts it plainly: "the field needs stronger long-term randomized evidence before making hard claims about persistence after device removal." When the company selling the product tells you the evidence isn't there yet, listen to them.
The Part That Actually Works, and Who It's Actually For
To be fair: there is a real signal here. A 2023 digital health study enrolled 2,217 participants across a range of glucose levels and paired CGM with a food and activity logging app. Participants saw improvements in glucose regulation and reported dietary shifts, including reductions in sugar and carbohydrate intake. The key word is "paired." CGM plus structured coaching plus food logging plus daily insights. Not just a sensor on your arm while you live your normal life.
This is the part the wellness industry glosses over. A 2025 ScienceDirect paper found that CGM can facilitate healthy lifestyle changes, but it may also cause psychological distress, particularly in younger adults and people with eating disorder symptoms. Distress coexisted with reported behavior change, sometimes acting as a motivator, sometimes as a barrier. A number that turns red when you eat pizza is not a neutral piece of information for everyone who sees it.
The clearest evidence for CGM in non-diabetic populations is in people with prediabetes, elevated metabolic risk, or obesity. Not in people who are already metabolically healthy and curious about their glucose curve. Healthy individuals, by one large study's finding, spend about 96% of their time in the normal glucose range already. There is not much signal to act on.
And critically: the behavior changes that do show up in studies require comprehensive support. One authoritative review concluded that "without comprehensive support and education, just wearing a CGM is unlikely to lead to lasting behavior change." A $99 sensor without a coach, without accountability, without a structured program, is mostly a very expensive conversation starter.
What to Do Instead (Right Now, Today, Free)
I want to be precise about who this device makes sense for. If you have prediabetes, a family history of type 2 diabetes, or your doctor has flagged your glucose trends, a CGM paired with a dietitian or structured program could be genuinely useful. That is a real population with a real need, and the evidence there is more compelling.
If you are otherwise healthy and thinking about buying a CGM because a podcaster told you your glucose variability is secretly killing you: please do not. Spend that $99 on groceries instead.
Here is what moves the needle for the vast majority of people, costs nothing, and has decades of evidence behind it. Sleep seven hours. Drink water. Walk 8,000 steps a day. Lift something heavy two or three times a week. Eat 100 grams of protein. You want specifics: two eggs at breakfast is 12 grams, a can of tuna at lunch is 25 grams, a chicken thigh at dinner is 28 grams, a Greek yogurt as a snack is 15 grams. That is 80 grams without thinking hard. Add a handful of edamame or cottage cheese. Done.
A CGM will tell you that the bag of chips at 10pm spiked your glucose. You already knew that. The problem was never information. The problem is that you were tired, stressed, and the chips were in the cupboard. No sensor fixes that. Going to bed at 10:30pm instead of midnight might.
The basics are not boring. They are undefeated. A $6 billion market is being built on the premise that you need more data before you can eat a vegetable and go for a walk. You don't. You need consistency, and you can start that today without sticking anything in your arm.
