Continuous glucose monitors are no longer just a tool for diabetes management. Over one million Americans without a diabetes or prediabetes diagnosis now wear a CGM regularly, according to combined usage estimates from Levels, Ultra, Nutrisense, and Lingo reported through Q1 2026. The devices are legal for over the counter purchase in the US after the FDA cleared Dexcom Stelo and Abbott Lingo in 2024. The user experience is undeniably interesting. The clinical question of whether wearing one actually improves long term health outcomes in otherwise healthy people is still mostly unanswered.
The pitch is reasonable on its face. A small sensor worn on the upper arm measures interstitial glucose every minute or two and streams the data to an app. Users see how specific foods, workouts, sleep patterns, and stress levels affect their blood sugar in real time. The idea is that seeing the data changes behavior. A user who watches their blood sugar spike to 190 after a bagel might choose eggs tomorrow. A user whose blood sugar stays flat after a particular meal might build more of their diet around that pattern. The feedback loop is fast and individualized.
The behavioral argument is not trivial. A handful of short term studies, most of them running eight to twelve weeks, have shown modest improvements in self reported diet quality and exercise adherence among CGM wearers. A 2024 randomized trial at Stanford placed 105 healthy adults into a CGM group and a control group for twelve weeks and found that the CGM group reported better food choice satisfaction and slightly lower average blood sugar at the end of the study. The effect sizes were small but consistent.
The problem is what happens after the twelve weeks end. The longer term data is thin because most studies have not run longer than a single quarter. The sustained behavior change question matters because the entire economic pitch of these devices depends on ongoing use at roughly $79 to $130 per month for a Levels or Nutrisense subscription, plus sensor costs. A user who drops off after three months because the novelty wears off has spent $300 to $400 on a fitness experiment rather than made a sustained health investment.
The glucose variability research is also more complicated than the consumer messaging suggests. The standard sales pitch emphasizes keeping blood sugar flat and avoiding spikes. The underlying research in non diabetics actually shows that healthy people experience meaningful glucose excursions multiple times per day in response to normal meals, and that these excursions are not clearly linked to any specific negative health outcome in people with normal insulin sensitivity. The relationship between postprandial glucose spikes and long term disease risk in non diabetic populations is contested, and the evidence base is mixed.
What the research does clearly support is that average glucose levels, measured as hemoglobin A1c, correlate with long term cardiovascular and metabolic risk even within the normal range. An A1c of 5.7 is healthier than an A1c of 5.9, which is healthier than an A1c of 6.1, even though all three are technically non diabetic. CGM data can provide a rough estimate of A1c through the glucose management indicator, but so can a standard blood test at a primary care visit for a fraction of the cost.
The user experience issue that usually gets less attention is the anxiety factor. A meaningful percentage of CGM wearers, particularly those with any baseline tendency toward health anxiety or disordered eating, report that seeing constant glucose data increases their stress about food choices, sometimes in ways that become counterproductive. Clinicians working in the space have started flagging this pattern, especially among younger female users. The device was designed for a clinical population that needed constant glucose awareness. Applying it to healthy populations changes the psychological context in ways the original design did not consider.
Cost is the other practical constraint. At $79 to $130 per month for the consumer subscription plans, the annual spend is $1,000 to $1,600 before any related service costs. That is not covered by most insurance for non diabetic users. For that same annual spend, a user could fund two comprehensive metabolic panel visits with a primary care physician, a quarterly DEXA body composition scan, a high quality home blood pressure monitor, and a year of a strength training gym membership. The opportunity cost for health spending is real.
The emerging sensible position among thoughtful clinicians is that CGMs are a useful short term educational tool for people with metabolic risk factors, family history of type 2 diabetes, or specific curiosity about their own metabolic response to food, but that continuous long term wear in otherwise healthy people is probably not the highest return use of health budget or attention. Wearing a CGM for four to eight weeks to learn how your body responds to common foods is reasonable. Wearing one for five years as a permanent fixture of a health routine is not supported by any current research.
The market will keep growing because the product experience is satisfying and the social media content around it is strong. The science will take another two to three years to catch up to the consumer adoption curve. People paying attention to the actual data should moderate their claims accordingly.