Over-the-Counter (OTC) CGM Market

Introduction to the Over-the-Counter (OTC) CGM Market

An over-the-counter (OTC) continuous glucose monitor (CGM) is a glucose sensor you can buy without a prescription. The category opened on March 5, 2024, when the FDA cleared Dexcom's Stelo as the first OTC CGM [1]. Abbott followed within three months, with clearances for Lingo on May 29, 2024 [3] and Libre Rio on June 7, 2024 [4]. As of October 2026, we could not confirm whether Libre Rio is on sale in the US.

These devices were cleared for adults who don't use insulin: people with type 2 diabetes managed with oral medications, and people without diabetes who want to see how food and exercise affect their glucose [1]. The FDA noted that Stelo is not for people with problematic hypoglycemia (low blood sugar), because it isn't designed to alert anyone to it [1]. In June 2026 the FDA extended Stelo's label to people 2 years and older who are not on insulin [5]. That's the shift this market represents: a CGM that started as a prescription tool for insulin users, sold as a consumer wearable for metabolic wellness.

Market Structure and Technology

For its first two years, the OTC market had exactly two sensor makers, Abbott and Dexcom, and both reused sensors they already sold by prescription. When we read the FDA summaries, the overlap was closer than we expected. Stelo "uses the same hardware design" as the prescription Dexcom G7; Dexcom changed the firmware to stretch wear from 10 days to 15 and to connect only to the Stelo app [6]. Lingo's biosensor is based on Abbott's FreeStyle Libre 2 sensor and is worn for up to 14 days [3]. That prescription Libre 2 sensor was itself available only through September 30, 2025, when Abbott replaced it with the FreeStyle Libre 2 Plus [7].

Both OTC sensors work the same way as their prescription parents. A thin filament sits under the skin, where the enzyme glucose oxidase reacts with glucose in the fluid between cells and produces a small electrical current that the sensor converts into a reading [2] [3] [8]. What Abbott and Dexcom changed was the software. Neither app gives glucose alarms [3] [6].

The two-company description no longer fits. On March 21, 2025, the FDA cleared the Signos Glucose Monitoring System, an OTC app that receives readings from the same sensor Stelo uses [8]. Signos added software, not a sensor. A third sensor maker arrived later. Biolinq's Shine sits in the upper layer of the skin (it is intradermal), lasts up to 5 days and shows a colored light rather than numbers, with more detail in an app [9] [10]. The FDA granted it a prescription-only De Novo authorization on September 23, 2025 [9], then cleared it for over-the-counter use in adults 22 and older not on insulin on September 18, 2026 [10]. As of October 2026, we have not confirmed that Shine is on sale.

Key Features and Risks

• Hardware and Software Differences: The hardware matches the prescription sensors; the software is where they part ways. Stelo's app updates every 15 minutes, displays glucose from 70 to 250 mg/dL, and offers time-in-range "Insights" with suggestions, but has no alerts [6]. Lingo's app displays 55 to 200 mg/dL and has no alarms [3]. Both labels say users shouldn't take medical action based on a reading without consulting a healthcare professional [3] [6].
• Glucose Anxiety: Some clinicians and commentators worry that people without diabetes will treat normal after-meal rises as a problem, a reaction sometimes called glucose anxiety. We did not find a study that measures it in OTC users. What we did find: the authors of the first independent accuracy study in adults without diabetes note that OTC sensors often reach buyers before any teaching on how to read the data, and they caution against threshold decisions such as self-screening for diabetes [11]. If a pattern worries you, that's a conversation for your care team.
• Accuracy Concerns: Independent accuracy data in the people these devices target is still thin. The FDA cleared Stelo on a study of adults with diabetes [6], and Abbott supported Lingo with data from the Libre 2 study in people with diabetes, arguing that their wider glucose swings are a worst case [3]. The first independent study in adults without diabetes, published in September 2026, had 39 participants. Against fingerstick meters it found an overall mean absolute relative difference (MARD, the average gap from the reference reading) of 12.9%. Agreement was worse after a sugary drink than after a placebo drink (15.3% vs 10.6%) and when glucose was changing fast, and the authors concluded the sensors follow trends better than exact values [11].
• Data Privacy: HIPAA, the main US health privacy law, covers health plans, clearinghouses, health care providers that file claims electronically, and the business associates working for them [12]. An OTC sensor bought off the shelf sends readings to the maker's app and cloud rather than to a clinic, so for many buyers the company's own privacy terms set the rules. Dexcom and Abbott both gave the FDA cybersecurity risk documentation for these systems [3] [6]. That review is about keeping the device and its data secure. It doesn't decide how a company may use your data.

Market Evolution and Third-Party Integrators

Signos is the clearest example we could document of value moving from the sensor to the software. Its app became an FDA-cleared OTC device in March 2025, and its indications add a line the Stelo label doesn't have: the information "may be useful in helping users to maintain a healthy weight" [8]. Levels, another app that works with CGM sensors, is often described as making a similar move toward data interpretation; we have not found an FDA record or other primary source that documents it. The common bet is that buyers will pay for an explanation of their readings, not just the readings.

Conclusion

As of October 2026, the OTC CGM market is two and a half years old. Sensors from Dexcom and Abbott, the Signos app and, since September 2026, Biolinq's Shine all hold FDA clearances for use without a prescription [1] [3] [8] [10]. What's still missing is independent evidence in the people buying them. We found one 39-person accuracy study in adults without diabetes [11] and no published measure of how often readings cause worry or lead to unnecessary changes. Until more arrives, the strongest documented use for these sensors is watching trends, and anything that looks like a medical problem belongs with a care team.