Pros

• Real-time tracking, shareable with up to 10 people
• Customizable alerts
• Discrete sensor

Editor's note, June 25, 2024: Since this article was first published, Dexcom has launched the G7. This sensor is smaller than the G6 and has an improved alert system, along with a few other differences.

"I find continuous glucose monitoring to be a valuable tool in the management of both type 1 and 2 diabetes," said Dr. Josh Emdur, medical director of SteadyMD. "CGM data provides actionable insight to help patients track their glycemic response to dietary choices and activity levels."

The Dexcom G6 doesn't require you to manually scan to get a glucose reading; instead, you get a wireless reading on a dedicated receiver device or on your phone or Apple Watch. The Dexcom G6 CGMs measure glucose levels in the interstitial fluid just under the skin every five minutes, keeping track of your blood sugar level as long as you're wearing it night and day. You can set a custom range for where you'd like your blood sugar to be, and if it falls into the low or high ranges you set, you will be notified. 

"For patients on an insulin pump, the Dexcom G6 may connect with your pump and offer a closed-loop system to turn off your insulin if you are going low. The Dexcom monitor is also approved in pregnancy and offers continuous monitoring that you can see on your phone at all times," said Dr. Rebecca Fenichel, an endocrinologist at Westmed Medical Group.

Stelo was the first over-the-counter CGM available in the US when it received FDA approval in 2024. The small sensor sits on the back of your arm and tracks your glucose levels 24/7. You can view your glucose levels within the app, and if you have an Oura ring, it pairs seamlessly. Levels are also viewable within the Oura app. Each sensor lasts up to 15 days, it's pretty low maintenance, and it's an easy way to see how your stress, meals and daily habits influence your glucose levels. One pack of two will cost you $99 (lasts about a month), but if you subscribe, that price will drop to $89 a month. The pack comes with everything you need: the sensors, applicator and overpatch to secure the sensor in place.

Over the two weeks I tested the Stelo, I noticed which habits (like taking a walk after dinner) affected my blood sugar the most. I find this tool helpful for those curious about their overall health, and probably not for those with a diabetes diagnosis, as it doesn't send safety alarms when your glucose levels are too high or too low. If you have a diagnosis and would like to try Stelo, I recommend speaking with your doctor to ensure it will provide the insights and alerts you need. Of the two OTC CGMs on this list (the other one is Lingo), our staff preferred the Stelo CGM.

Editor's note, Feb. 4, 2026: Certain FreeStyle Libre 3 and FreeStyle Libre 3 Plus sensors have been recalled due to incorrect glucose readings. To find out whether your sensor is included in the recall and what to do, read the FDA's recall alert.

The Freestyle Libre 2 was previously on this list and recommended by Dr. Nate Favini. "For people who are interested in deeper insights into their glucose levels, I'll often recommend the Freestyle Libre for continuous glucose monitoring," Favini said.

Since then, the device has been updated to the Freestyle Libre 3 Plus (previous models will be discontinued). It essentially works the same way as its predecessor: you place the sensor on your arm and can track your glucose levels throughout the day. The biggest differences between the Freestyle Libre 2 and 3 are that the newest model lasts 15 days (versus 14 days on the 2) and the size of the sensor (the 3 is smaller and thinner). Another new feature of the Libre 3 Plus is that this sensor is compatible with automated insulin delivery systems (also known as pumps), and Abbott has partnerships with most major pump partners.

If you want a device that you can set up and don't have to worry about reinserting for an entire year, Eversense 365 is a great option for diabetes management. A health care provider will insert the sensor and then you place the transmitter above that. 

Once the sensor is in place, you don't have to change it out for about 12 months, a long sensor life. The transmitter itself can alert you if your blood sugar is too high or low, and you can also have wireless readings sent to your phone via an app. You can share your blood glucose data from your app with your doctor or anyone else who wants to check your blood sugar readings.

Lingo is one of the two over-the-counter continous glucose monitors we tested on this list. Like the Stelo, Lingo is worn on the back of the upper arm and you can view your glucose data within the Lingo app, where it's translated into an easy-to-read chart. The app also includes habit-building challenges and progress tracking, making glucose monitoring feel more like a game than a chore. The Lingo app is available for iPhone and Android users.

What I appreciated most was how lightweight and low-maintenance the sensor is. It's pretty sleek, and you don't have to worry about carrying a reader. I do recommend buying an overpatch as this sensor doesn't come with one and the first time I tested I accidentally yanked it off while dressing myself. An overpatch will ensure the device stays securely on your arm.

A single sensor costs $49 (lasts up to 14 days), a two-sensor pack costs $89 (about a month's supply), and buying in bulk (six sensors for 12 weeks) will save you the most money at $249. Lingo is also the only OTC CGM available in brick-and-mortar stores in the United States.

The Guardian Connect System is a CGM that can tell you your current glucose readings quickly via a connected app and also lets you easily access trends and data about your blood sugar over time. One feature that stands out with the Guardian is the "predictive" alerts you can get about your sugar. Unlike other CGM systems that alert you when your sugar is already high or low, the Guardian uses technology that predicts when your blood sugar might get high or low before it happens. Another feature that comes with the monitor is the Sugar.IQ diabetes assistant app for diabetes management, which uses your data to help you figure out what diet, exercise and insulin works best for you.

Yes, there are two continuous glucose monitors that are available without a prescription. You can also get a regular glucose monitor without a doctor.

Many insurance plans, including Medicaid and Medicare, will cover a continuous glucose monitor, although they may require prior authorization.

The Abbott Freestyle Libre 2 sells for just $103. The cheapest way to get a continuous glucose monitor is to go through your insurance, Medicaid or Medicare; you could potentially get one for free.

It’s recommended to wear your CGM on the back of your upper arm. Some models allow placement on other areas, like the thigh, but always check the manufacturer’s instructions. Avoid placing it on scars or other skin irregularities.