Are CGM's Waterproof?

We’re headed into the dog days of summer and that means families and friends across the United States are gathering to share poolside afternoons and sunny beach days. For those living with diabetes, fun in and around the water comes with some added challenges, particularly for those who rely on a continuous glucose monitoring device (CGM), such as the popular FreeStyle Libre 2, Freestyle Libre 3, Dexcom G6 and Dexcom G7 for real-time blood glucose calculations.


What is a Continuous Glucose Monitoring Device?

Continuous glucose monitoring (CGM) is an effective way for those with Type 1 diabetes, and many with Type 2 diabetes, to measure blood sugar without the need for daily finger pricks and test strips. CGM devices provide real-time glucose measurements throughout the day – as often as every minute. They work using a sensor that is attached to the body, usually on the upper arm or abdomen. This sensor transmits blood sugar readings wirelessly to a remote device or smartphone app. If you know anything about CGM, you know it’s a game changer for countless people living with diabetes. However, CGM solutions are attached to the body, which means for activities like swimming it’s important to take caution.


Can I swim with a Continuous Glucose Monitoring Device?

The good news is the answer is yes. Most CGM solutions are water resistant and can be submerged in water for a limited time, so you’re able to enjoy the water while wearing a CGM device. However, it’s important to remember there is a big difference between “waterproof” and “water resistant”. CGM’s are not waterproof. They cannot stay submerged indefinitely, additionally, there are limits to how deep they can go.

So, when it comes to CGMs and swimming, there are limitations. Plus, devices differ in their ability to withstand use in the water, therefore, it’s important to understand these limitations and be cautious anytime you are swimming or spending time in the water while using a CGM device and sensor. With this in mind let’s look at the water basics of a few popular devices.


FreeStyle Libre 2

According to manufacturer specifications, the FreeStyle Libre 2 sensor is water resistant for a depth up to 3 feet. It can also be immersed in water for no longer than 30 minutes. Clearly, this doesn’t pose a problem when showering or bathing. But swimming is a different story. If you are swimming for exercise in a lap pool and staying on the surface (above 3 feet deep), you should have no problems provided your workout stays within the 30 minutes immersion time frame.


Dexcom G6 and Dexcom G7

Once again, the sensors for the Dexcom G6 and Dexcom G7 CGM devices are classified as water resistant. These sensors, however, are rated for submersion of up to 8 feet and can be immersed in water for up to 24 hours without failure, provided they have been properly installed. Showering and bathing are clearly not a problem, plus the added immersion time and depth may provide greater peace of mind for those swimming laps or spending more time in a pool.


What about the beach? What about a hot tub?

CGM sensors tested in pure water. They are not tested in saltwater, chemically treated water, or heated water. Additionally, they are not tested for movement that might put added force or friction on the sensor. So, these factors could all have an impact on performance. Additionally, forces and friction can cause a sensor’s adhesive to weaken, which might lead to a loose sensor or even one that comes off the body. Sliding down a waterslide, playing in waves at the beach, or participating in active watersports might all cause sensors to come loose.

Going to the beach is a big concern for many people with diabetes who use CGM devices, and for the most part we hear of few problems, provided the time spent in the ocean and physical activity are carefully monitored.


Can I Make A CGM Sensor Waterproof?

Sorry, but this is not possible. Yet.


What About CGM Receivers?

If you use a CGM device, it’s either linked to a mobile app on your smartphone, or you use the manufacturer’s compatible CGM receiver to get your blood sugar readings. Neither of these is waterproof! Yes, there are waterproof cases on the market for smartphones, and they’re certainly a possibility and can prove advantageous. However, the best bet for most people is to keep their phones and receivers away from the pool, out of the sun, in a bag or locker, while swimming. Just be sure to take the time to check your blood sugar readings while working out or having fun!


What Else Can I Do?

The primary problem associated with swimming while wearing a continuous glucose monitoring sensor is the risk of the adhesive bond with the skin becoming compromised. But there are ways to prevent this from happening.

Special Adhesive Patches

Even though sensors are designed to adhere to the body and usually do a very good job of it, a lot of time in the water and physical movement can lead to problems with adhesion. To help there are special adhesive patches designed for specific CGM devices. For example, companies like Skin Grip create products for both Dexcom G6 Patches and Freestyle Libre Patches that are designed to keep the sensors firmly in place.

These patches are latex free, FDA approved and hypoallergenic. Plus, they are sweat-proof and made to keep sensors safe and in place despite physical activity. It’s important to note that Skin Grip CGM adhesive patches do not increase water resistance. They do; however, help keep CGM sensors firmly in place while being active - whether in or out of the water.

Sensor Arm Bands and Straps

Another great way to add a little confidence to your swimming routine is with an arm band or strap that is designed specifically to fit over your type of CGM sensor. You’ll find a variety to choose from on the market. Again, these bands and straps do not magically make your CGM sensor waterproof (though you will see claims of “waterproof” out there, it’s not accurate). What they do is help prevent rubbing or other types of friction from compromising the sensor’s seal with the body.


What if?

This summer you should feel free to go out there and jump in a pool or even wade the ocean with your CGM sensor. It’s just important that you take a few extra precautions. If your sensor does happen to come off, it’s not the end of the world – just the end of that sensor. You’re going to need to apply a new one, so it’s a good idea to have one nearby. Also, if your blood sugar readings are not consistent with how you feel, go ahead and perform a blood glucose test using a glucose meter and test strip for added clarity. It’s always better to err on the side of caution when it comes to diabetes management.


We hope you found this post informative and insightful. At Diabetic Warehouse, we’re committed to helping those with diabetes manage blood sugar with a complete selection of testing and treatment supplies at prices up to 65% less than those found at most pharmacies and suppliers.

Diabetic Warehouse is a trusted supplier of diabetes care products and accessories. For more information and to explore a complete range of products, including glucose meters and test strips, insulin syringes, pen needles, continuous glucose monitoring systems, and more, visit