FreeStyle Libre Systems: Continuous Glucose Monitoring (CGM)
FreeStyle Libre is a brand of continuous glucose monitoring (CGM) systems designed to help people with diabetes track their glucose (blood sugar) levels throughout the day and night. These systems use a small sensor worn on the back of the upper arm to measure glucose levels in the fluid just beneath the skin.
The sensor sends glucose readings to a compatible smartphone app or reader, depending on the model. The app or reader displays your current glucose level, a trend arrow showing whether your glucose is rising or falling, and information about your glucose patterns over time. Some systems can also alert you when your glucose is too high or too low.
FreeStyle Libre systems reduce the need for routine finger-stick blood glucose testing, making glucose monitoring more convenient. However, finger-stick testing is still necessary in certain situations.
Continuous glucose monitoring is particularly useful for people with type 1 diabetes and those with type 2 diabetes who use insulin or other medications that can cause low blood sugar (hypoglycemia). It may also benefit other people with diabetes who need help understanding their glucose patterns.
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How do I use a FreeStyle Libre system?
A small sensor is applied to the back of your upper arm using a disposable applicator. The sensor is designed to remain in place during normal daily activities, including sleeping, bathing, and exercise. It is water-resistant, although limits on swimming depth and time in water vary by model.
The FreeStyle Libre 2 Plus and FreeStyle Libre 3 Plus sensors can be worn for up to 15 days before they need to be replaced.
Depending on the system, glucose readings are transmitted automatically to a compatible smartphone app or reader. Some older models require scanning to obtain readings. You can view your glucose level, track trends, and receive alerts when your glucose is outside your target range.
Talk to your healthcare provider about how to use the system and interpret your glucose readings. Your provider can also help you establish appropriate glucose targets.
How does the FreeStyle Libre measure glucose levels?
FreeStyle Libre sensors measure glucose in the interstitial fluid, which surrounds the cells beneath your skin, rather than directly measuring glucose in your blood.
Because glucose moves between the blood and interstitial fluid, sensor readings may differ from finger-stick blood glucose readings, particularly when glucose levels are changing rapidly, such as after meals, exercise, or insulin administration.
The system uses these measurements to help you monitor glucose patterns and make informed decisions about your diabetes management.
Who should not use a FreeStyle Libre system?
FreeStyle Libre systems are not suitable for everyone. Age restrictions and other precautions depend on the specific model. The FreeStyle Libre 2 Plus and FreeStyle Libre 3 Plus sensors are approved for people with diabetes ages 2 and older.
You may need to use a finger-stick blood glucose test instead of relying on your sensor reading in certain situations, including when:
- Your symptoms do not match the sensor reading.
- Your glucose levels are changing rapidly.
- The system does not display a glucose value or indicates that a finger-stick test is needed.
- You believe a sensor reading may be inaccurate.
Always follow the instructions for your specific device. Keep a blood glucose meter available in case you need to confirm a reading or your sensor is not working properly.
How can I get a FreeStyle Libre system?
FreeStyle Libre CGM systems require a prescription in the United States. Sensors and compatible readers are available through participating pharmacies and medical equipment suppliers.
Insurance coverage and out-of-pocket costs vary depending on your health plan. Talk to your healthcare provider to determine whether a FreeStyle Libre system is appropriate for you and which model best meets your needs.
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