Most people think the risk of swimming with a FreeStyle Libre sensor is that it will stop working.
In practice, that’s rarely the problem.
Sensors come off.
Water, heat and movement can weaken the adhesive, especially in pools, the sea or hot tubs. Once that starts, the sensor can lift or get knocked off completely.
For anyone swimming with a CGM, this is often the difference between a sensor lasting the full wear period or needing to be replaced early.
Can you swim with a FreeStyle Libre sensor?
Yes, you can.
FreeStyle Libre sensors are designed to be worn while bathing, showering and swimming. The manufacturer guidance is:
- Up to 1 metre depth
- Up to 30 minutes in water
These limits come from controlled testing conditions. Real-world swimming is less predictable.
If you’re swimming with a CGM, understanding how water affects adhesion is just as important as knowing these limits.
Many people ask if you can swim with Libre 2 or Libre 3. The answer is yes, but the same water limits apply.
Water-resistant vs waterproof
Water-resistant does not mean the sensor is designed for long swims or high movement in water.
FreeStyle Libre sensors are rated IP67 water-resistant, not waterproof.
This means they have been tested:
- In fresh water
- Without movement
- For up to 30 minutes
- At a depth of 1 metre
Swimming introduces different conditions:
- Movement and friction
- Chlorine or salt
- Changes in pressure
- Heat from hot tubs or spas
These increase the chance of the sensor loosening.
There is no way to make a CGM sensor fully waterproof.
Libre readers should always be kept dry. They are not water-resistant or waterproof and need to be kept well away from the water at all times.
How does this compare to Dexcom sensors?
CGM and insulin pump water resistance comparison
| Device | Water rating | What it means in practice | Key risk in water |
|---|---|---|---|
| FreeStyle Libre sensors | IP67 | Up to 1 metre for 30 minutes (tested in still, fresh water) | Adhesive weakening, sensor coming off |
| Dexcom G7 / Dexcom ONE+ | IP68 | Continuous immersion, typically deeper and longer than IP67 (manufacturer conditions apply) | Adhesive weakening, sensor coming off |
| Tandem t:slim X2 insulin pump | IPX7 | Splash-proof and brief immersion only (not designed for swimming) | Water ingress if submerged |
| Medtronic MiniMed 770G | IPX8 | Suitable for deeper immersion within limits set by manufacturer | Seal wear over time |
| Omnipod DASH | IP28 (IPX8 equivalent) | Waterproof for up to 7.6 metres for 60 minutes | Adhesion and wear over time |
Water ratings describe device exposure limits, but they do not prevent CGM sensors from coming loose during swimming.
Some CGM systems, such as Dexcom G7 and Dexcom ONE+, are rated IP68.
This is a higher water-resistance rating than IP67.
In practice, IP68 means:
- Designed for continuous immersion in water
- Typically tested beyond 1 metre depth
- Often for longer periods (for example up to 24 hours in some manufacturer specifications)
However, this does not remove the real-world issue.
Even with IP68-rated sensors, the main reason sensors fail in water is still adhesion.
Water, heat and movement can still:
- Weaken the adhesive
- Cause edges to lift
- Increase the risk of the sensor being knocked off
So while Dexcom sensors may tolerate water exposure differently, they are still affected by the same physical forces during swimming.
Why do CGM sensors come off when swimming?
The most common reasons Libre sensors come off when swimming are:
- Adhesive weakening in water
- Friction from swimming or water sports
- Heat softening the adhesive
- Salt or chlorine affecting the edges
- Skin becoming too dry or overhydrated
It is usually a combination of these factors.
Many people only realise how easily a CGM sensor can come off in water after it happens once.
The moment most sensors fail in water
It’s rarely while you’re actually swimming. It usually happens when you’re not thinking about it, after the swim rather than during it.
the sensor is most likely to lift or come off when:
- You push off the pool wall
- You dry off with a towel
- Clothing or straps catch the edge
- The adhesive has already weakened
Can water affect sensor readings?
It can, but this is less common.
Most issues relate to the sensor coming loose rather than stopping working. Of course exercise may affect glucose readings and the temperature of the water can also have an effect.
Can you make a FreeStyle Libre sensor waterproof?
No.
Patches, plasters and stickers:
- Do not increase the waterproof rating
- Can trap water underneath
- May weaken adhesion
- Can irritate skin
If something fully sealed the sensor, the skin would not be able to breathe.
What helps when swimming with a CGM?
If you’re swimming with a CGM, the goal is not to make it waterproof.
It is to reduce movement, friction and stress on the adhesive.
This is exactly the situation many Libreband users are trying to avoid.
A reusable armband such as a Libreband can help:
- Reduce friction in water
- Support the sensor if adhesion weakens
- Protect against knocks during activity
- Be removed afterwards so the skin can dry
This approach focuses on support rather than sealing.
What about insulin pumps?
Water resistance varies by device, and it’s important to check the rating before swimming. Before swimming, it’s always best to follow the specific guidance for your device.
Some pumps are described by their manufacturer as ‘watertight’ and this usually means that they can withstand rain and splashes, but are not suitable for submersion.
For example, Tandem pumps are watertight to IPX7 standard but are not suitable for wearing while showering, swimming or diving.
Some Medtronic pumps (MiniMed 630G & 770G) are waterproof with a IPX8 standard, to a limited depth and time and the tubeless Omnipod Dash has an IP68 rating for submersion up to 7.6m for 60 minutes.
Due to general wear and everyday bumps, all pumps can develop tiny cracks which may not be visible but which can make the pump susceptible to water damage. Swimmers should check the pump manufacturer’s instructions before exposure to water.
Over time, everyday wear, knocks and small cracks can reduce water resistance. That means devices may not perform exactly as they did when new.
Simple tips for swimming with a FreeStyle Libre sensor
- Rinse skin after swimming to remove chlorine or salt
- Dry the area fully afterwards
- Moisturise once skin is dry
- Stay hydrated
- Check the sensor edges regularly
- Avoid long periods in hot tubs
Final thoughts
Many people swim with a FreeStyle Libre sensor without experiencing problems. However, once you understand that the real risk is the sensor coming loose, not failing, it changes how you approach swimming and other water activities.
Reducing friction and supporting the sensor is often the difference between a sensor lasting the full wear period or coming off early.
Read also: Top 10 Tips for getting your Libre sensor to stick.
You can see our video on Swimming with a Libre Sensor here.
Disclaimer
Love My Libre is not associated or affiliated with Abbott or FreeStyle Libre. Content here and on our website www.lovemylibre.com does not constitute medical advice or replace the relationship between you and healthcare professionals nor the advice you receive from them.
The author of this blog has type one diabetes and uses a CGM provided on NHS prescription.
FreeStyle Libre is a registered trademark of Abbott Diabetes Care Inc.
Strath Clarke
October 25, 2023
Hi,
I’ve Scuba dived with my Libre Sensor without any issues afterwards.
Eight dives to 20 m depth and around 40 minutes per dive with the same sensor.
The sensor also survived donning and doffing (yep – that’s the word) my tight wetsuit.
Just need to work out a way of reading the sensor underwater.
Strath