Josh Clemente was 28, working 20-hour days as a life support systems engineer at SpaceX, and convinced he was dying. Not dramatically. Quietly. He hit walls multiple times a day, crashed through afternoons, and slept under his desk when he could sleep at all. Doctors said he was fine. Blood panels came back normal. But the fatigue was real, and it was wrecking his output.
Then a friend brought him a continuous glucose monitor from Australia, where the devices were sold over the counter. Clemente stuck the sensor on his arm and saw what no lab panel had shown: his blood sugar looked like a heart rate trace. Wild spikes after meals. Crashes that lined up exactly with his afternoon brain fog. He was eating himself into a metabolic roller coaster every single day, and his standard bloodwork never flagged it.
A continuous glucose monitor (CGM) is a small wearable sensor that tracks your blood sugar levels in real time, reading interstitial glucose every 1 to 15 minutes and sending the data to your phone. In 2026, you do not need a prescription or a diabetes diagnosis to buy one. The FDA cleared the first over-the-counter CGM in 2024, and two major devices are now available at retail for anyone who wants them.
Clemente went on to found Levels, a metabolic health startup that raised $38 million. But the bigger story is what happened after those OTC approvals. A growing number of founders, operators, and high-performers are strapping on glucose monitors not to manage disease, but to understand why their energy tanks at 2pm, why some meals leave them sharp and others leave them foggy, and whether the $89/month cost is worth the clarity.
Last updated: April 2026
Should non-diabetics use a continuous glucose monitor?
The short answer: probably yes, if you want data on how food, stress, and sleep affect your energy and you are willing to act on what you find. The longer answer depends on what you expect the device to do.
A CGM will not diagnose disease. It will not tell you if you are pre-diabetic with clinical accuracy (the Mass General Brigham research team found that CGM metrics lose their correlation with HbA1c in people without diabetes). What it will do is show you, in real time, the metabolic cost of your choices. That bagel you eat before your 9am standup? You might see a spike to 160 mg/dL followed by a crash to 75, right when you need to be making decisions. The salad with grilled chicken? Flat line. Same person, same morning, completely different cognitive trajectory.
For founders specifically, the value is not clinical. It is operational. You are running a company on a body, and most founders have no idea how that body is actually processing fuel. It is the same blind spot that drives the growing interest in nootropics for cognitive performance and optimized sleep schedules: founders are starting to treat their biology as infrastructure.
A 2024 study in Nature’s Nutrition and Diabetes measured cognitive function alongside continuous glucose data in real-world conditions. Participants with higher insulin resistance showed measurable drops in working memory during glucose fluctuations throughout their normal days. The effect was not hypothetical. It showed up in ambulatory testing while people went about their lives.
The practical takeaway: glucose variability affects your brain, even within ranges that doctors consider “normal.” A CGM makes that variability visible.
What does a CGM actually tell you?
A CGM reads your glucose levels continuously through a tiny sensor filament inserted just under the skin, usually on the back of your upper arm. The sensor measures glucose in interstitial fluid (not blood directly) and transmits readings to an app on your phone.
Here is what the data actually looks like in practice. You will see a line graph that moves throughout the day. After meals, the line rises. After exercise or fasting, it falls. Stress, poor sleep, and even caffeine can push it up. The patterns are uniquely yours. Two people can eat the same meal and get completely different glucose responses.
The metrics that matter for performance optimization are glucose variability (how much your levels swing throughout the day), time in range (what percentage of the day you stay between roughly 70-120 mg/dL), and post-meal spikes (how high and how fast your glucose rises after eating). Founders who track these numbers for even two weeks start seeing patterns: which meals keep them steady, which ones send them on a roller coaster, and which times of day their metabolism handles carbohydrates best.
One thing CGMs will not tell you: the “why” behind every spike. Stress hormones like cortisol and adrenaline raise blood sugar independently of food. A tough investor call can spike your glucose just like a bowl of pasta. (This is part of why sleep quality matters so much for founders: poor sleep raises baseline cortisol, which raises baseline glucose.) Levels Health documented this pattern across thousands of users and found that stress-induced glucose spikes were among the most common surprises for new CGM wearers.
The OTC CGM landscape in 2026
Two companies dominate the over-the-counter CGM market right now: Dexcom with its Stelo biosensor and Abbott with Lingo. A third option, NutriSense, pairs prescription CGM hardware with a coaching platform. Each device serves a slightly different user.
Dexcom Stelo was the first FDA-cleared OTC glucose biosensor, approved in March 2024. It uses a 15-day sensor with readings every 15 minutes and has a MARD (mean absolute relative difference, the accuracy metric) of 8.3%. It costs $99 for a one-time two-pack or $89/month on subscription. Stelo is the only OTC CGM that supports direct data sharing with healthcare providers. It is also fully waterproof to eight feet for 24 hours.
Abbott Lingo launched in the U.S. in September 2024. Its sensor lasts 14 days and reads every minute, giving you much denser data than Stelo. MARD is approximately 9.3%, slightly less accurate but still solid. Pricing is more flexible: $49 for a single sensor, $89 for a two-pack, or $249 for a 12-week subscription. Lingo’s app includes a proprietary “Lingo Count” scoring system that rates your meals, though reviews are mixed on whether that scoring is helpful or confusing.
NutriSense takes a different approach. You get a prescription-grade CGM (typically the Abbott Libre 3) paired with a dietitian who reviews your data. Plans start around $225/month. The hardware is better, but you are paying for the human coaching layer.
| Device | Sensor life | Reading frequency | Monthly cost | Best for |
|---|---|---|---|---|
| Dexcom Stelo | 15 days | Every 15 min | $89-99 | Data sharers, simplicity seekers |
| Abbott Lingo | 14 days | Every 1 min | $49-89 | Granular trackers, budget-conscious |
| NutriSense | 14 days | Every 1 min | ~$225+ | People who want dietitian coaching |
All three options are HSA/FSA eligible. None are covered by insurance for non-diabetic use.
Why founders are the fastest-growing CGM audience
The wellness CGM segment accounted for 41% of OTC device revenue in 2024, according to Grand View Research. That number is growing. The broader CGM market hit $15.3 billion in 2026 and is projected to reach $31.4 billion by 2031, a 15.4% compound annual growth rate.
Founders are drawn to CGMs for the same reason they track MRR, CAC, and burn rate: you cannot optimize what you cannot measure. The specific use case that resonates most in founder circles is not weight loss or diabetes prevention. It is cognitive consistency.
The same impulse is driving founders toward GLP-1 medications for metabolic optimization, though CGMs and GLP-1s serve different purposes (monitoring vs. intervention). Here is the pattern that keeps showing up in biohacking communities like r/biohackers and founder Slack groups: a high-performer straps on a CGM, expects to see relatively flat glucose, and discovers their afternoon crashes are directly tied to what they ate at lunch. The data makes the invisible visible. A rice bowl that “felt healthy” spiked their glucose to 170 and left them useless for two hours. A handful of almonds and a protein shake kept them at 95 and they crushed their afternoon.
The ROI calculation is simple enough that it appeals to the founder brain. If a CGM helps you eliminate two energy crashes per week, and each crash costs you 60-90 minutes of productive time, that is 8-12 hours per month of reclaimed high-quality work. At $89/month for a Stelo subscription, the cost per reclaimed hour is under $12.
How much does a CGM cost without insurance?
An OTC CGM costs between $49 and $99 per month depending on the device and plan. Dexcom Stelo runs $89/month on subscription or $99 for a one-time two-pack of 15-day sensors. Abbott Lingo is cheaper at $49 for a single 14-day sensor or $89 for two. NutriSense, which bundles dietitian coaching, starts at roughly $225/month.
None of these are covered by insurance when purchased for wellness rather than diabetes management. However, all major OTC CGMs are eligible for HSA and FSA spending, which means you can use pre-tax dollars. If you have an HSA with invested funds, the effective cost drops further.
For a 30-day experiment (the minimum most people need to identify patterns), budget $89-198 depending on which device you choose. Many founders treat this as a one-time diagnostic rather than an ongoing expense. Wear it for a month, identify your worst glucose triggers, adjust your meals and routines, then stop. You keep the knowledge without the recurring cost.
The 30-day founder CGM experiment
If you want to try a CGM without committing to an ongoing subscription, here is a structured 30-day protocol that maximizes what you learn.
Week 1: Baseline. Eat normally. Do not change anything. The point is to see your real patterns, not your “trying to be healthy” patterns. Log your meals in the app (both Stelo and Lingo have food logging). Note your energy levels alongside the glucose data. You are looking for correlations between spikes/crashes and how you actually feel.
Week 2: Meal testing. Systematically test the meals you eat most often. Eat your usual breakfast and watch what happens. The next day, swap one variable (swap oatmeal for eggs, skip the orange juice, add protein). Compare the glucose curves. Do the same for lunch. Most people discover 2-3 meals that are silently wrecking their afternoons.
Week 3: Stress and timing experiments. Track how your glucose responds to stressful meetings, late nights, exercise at different times, and caffeine. Cortisol raises blood sugar independently of food, so you may see spikes during investor calls or high-stakes presentations. This is where the data gets interesting for founders specifically. A study in Psychoneuroendocrinology documented how chronic stress dysregulates the cortisol-glucose relationship, creating a feedback loop of elevated blood sugar and impaired cognitive function.
Week 4: Optimization. Apply what you learned. Build a meal rotation around the foods that kept your glucose stable. Schedule your hardest cognitive work during the windows when your glucose is most consistent. For most people, this means pushing carb-heavy meals to the evening and keeping daytime meals protein-and-fat-forward.
By day 30, you should have a clear picture of your personal glucose triggers, your best eating schedule for cognitive performance, and whether the ongoing data is worth the monthly cost.
What the skeptics get right
Not everyone in medicine is sold on CGMs for healthy people. Johns Hopkins published a 2026 analysis questioning whether glucose monitoring provides meaningful health data for non-diabetics. The core argument: CGM readings do not reliably predict long-term disease risk in people with normal metabolic function, and the psychological burden of constant monitoring could cause more anxiety than benefit.
That is a fair point. Some people become obsessive over small glucose fluctuations that are completely normal (a post-meal rise to 140 is physiologically typical and not dangerous). The cost is also real. Spending $1,000+/year on a monitoring device you do not medically need is a privilege, not a necessity.
The counterargument from the founder crowd is straightforward: the value is not medical prediction. It is performance feedback. You do not need a CGM to tell you if you are pre-diabetic. You need a CGM to tell you that your Tuesday lunch is costing you two hours of productive afternoon work. That is a different use case than what most medical studies evaluate, and it is the use case that is driving adoption among high-performers.
The honest position: a CGM is a useful short-term experiment for anyone curious about their metabolic patterns. It is probably not worth wearing forever if you are metabolically healthy. But a month of data can permanently change how you eat, and that knowledge does not expire when you take the sensor off.
What comes next for non-diabetic glucose monitoring
The OTC CGM market is still new. Stelo and Lingo both launched in the last 18 months, and the technology is improving fast. Sava, an early-stage wearable company, is developing a multi-biomarker patch that tracks glucose alongside cortisol, lactate, and ketones simultaneously. If that ships, founders get a single device that maps the full metabolic picture instead of just glucose.
The broader CGM market is projected to more than double by 2031, reaching $31.4 billion globally. Non-diabetic wellness is the fastest-growing segment. As prices drop and accuracy improves, expect CGMs to become as common in founder circles as sleep trackers are today. Founders who are already experimenting with vagus nerve stimulators and stacking nootropics for focus will be the first wave of multi-biomarker adopters.
For now, the technology is good enough to answer the question that matters most: is what you are eating actually working for you? For $89 and 30 days, you can find out. A continuous glucose monitor will not build your company for you, but it might explain why your best thinking keeps stalling after lunch.
