What to know about the FreeStyle Libre Continuous Glucose Monitor

The FreeStyle Libre system is a continuous glucose monitor (CGM) worn on the upper arm that provides real-time blood sugar (glucose) readings. It is suitable for people with type 1 diabetes or type 2 diabetes, especially those who take insulin.

This article looks at how the FreeStyle Libre system works, the advantages and limitations of the device, and when traditional fingerstick testing may be required.

How FreeStyle Libre Works

The FreeStyle Libre system provides real-time glucose readings every minute, 24 hours a day. There are two systems to choose from:

  • Freestyle Libre 14 Day System (for adults 18 and older)
  • Freestyle Libre 2 System (for adults and children 4 and up)

FreeStyle Libre is a new generation of CGM that doesn’t require bulky transmitters. Instead, use the supplied applicator to place a small waterproof sensor with a tiny probe on the back of the arm.

FreeStyle Libre tests the fluid in the space around cells, which is as effective for monitoring blood sugar as blood from capillaries (small blood vessels, such as fingertips).

One hour after applying the sensor, the system is ready. The sensor takes a glucose reading every 60 seconds. A separate reader device remotely captures and records readings on demand. You can then view the results individually or see trends in glucose levels over time.

To get a reading, place the reader within 1.5 inches of the sensor.You can scan the sensor as often as you want, but it is recommended that you perform a scan At least Every eight hours. (There are FreeStyle Libre apps in the App Store and Google Play that turn your smartphone into a reader).

The sensor can be worn for up to 14 days and stores results for 90 days. After 14 days, the sensor stopped working and needed to be replaced.

FreeStyle Libre 2 is also equipped with an alarm to notify you when your blood sugar levels are too high or too low. The original FreeStyle Libre 14-Day did not have this feature.


FreeStyle Libre consists of a remote reader and a waterproof sensor mounted on the back of the arm. To check your glucose, the reader is placed immediately above the sensor. The reader can capture and store glucose readings for up to 90 days.

Blood Glucose Testing Guidelines


CGM devices like FreeStyle Libre offer advantages over traditional fingertip monitoring. Studies have shown that people with diabetes who have their blood checked regularly have more stable blood sugar levels. They also had lower A1C, a measure of long-term blood sugar control.

CGM devices are also better at preventing hypoglycemia (low blood sugar), including nocturnal hypoglycemia.

With the FreeStyle Libre System, you don’t have to draw blood multiple times a day to ensure your blood sugar stays within the normal range.

In addition to being more convenient, the device is also painless. This may prompt people to measure their blood sugar more frequently.

Another unexpected advantage of the FreeStyle Libre system is that it appears to reduce the cost of diabetes care.According to a study published in 2020 American Endocrinologythe FreeStyle Libre system reduced annual medical bills for diabetics by more than 50% compared to users of the finger prick test.


Compared to finger prick testing, continuous glucose monitoring devices like FreeStyle Libre can help people keep blood sugar levels more stable, prevent hypoglycemic episodes, and reduce A1C. Several studies have shown that the device could reduce the annual cost of diabetes care.

Glucose monitor communicating with insulin pump


However, the FreeStyle Libre system does have some limitations.

Among them, the original FreeStyle Libre 14-Day is not equipped with an alarm clock function, which may not be the best choice for people who are unconscious with hypoglycemia. This is a condition where people don’t realize when their blood sugar levels have dropped badly.

Although the FreeStyle Libre system was about 92% accurate in the study, Sometimes inaccuracies occur. This happens when blood sugar changes rapidly, such as after eating, taking insulin, or exercising. Severe dehydration can also affect readings.

Therefore, the Libre FreeStyle reader has a built-in blood glucose meter. This allows you to perform a finger prick test to ensure accurate CGM readings. This is especially helpful if readers say your blood sugar levels are too high or too low.

The FreeStyle Libre sensor is waterproof, but should not be soaked for more than 30 minutes. Unused sensors can be stored in a dry place at room temperature.


FreeStyle Libre 14-Day does not have an alarm function and may not be suitable for people who are unconscious of hypoglycemia. The device may also be less accurate if you are severely dehydrated or have just finished eating, exercising, or taking insulin.

cost and availability

The FreeStyle Libre system is available at pharmacies with a prescription. The sensor retails for about $85 for FreeStyle Libre 14-Day and about $130 for FreeStyle Libre 2. The reader costs about $65 (free if you download the app to your smartphone).

For those with private insurance or Medicaid, expect to pay between $40 and $75 a month out of pocket. For those who qualify, this product is fully covered by Medicare.

Additionally, the FreeStyle Libre system uses test strips called Precision Neo test strips for fingerstick testing. A box of 50 individually wrapped strips costs about $20. Using other test strips with built-in meters may produce errors.


Retail prices for each 14-day sensor range from $85 to $130. With insurance, out-of-pocket costs can be as low as $0 to $75 per month.

Comparison with other devices

FreeStyle Libre is known as a rapid blood glucose monitoring system. Unlike other CGMs like the Medtronic Guardian 3 and Dexcom G6, FreeStyle Libre checks glucose levels every minute instead of every five minutes. It can also be worn for 14 days, compared to 7 days for the Medtronic Guardian and 10 days for the Dexcom G6.

The FreeStyle Libre system does not require finger prick calibration. Also, since there is no transmitter, the cost of the system is lower than other CGMs.

While other CGM sensors can be placed on the abdomen and buttocks, the FreeStyle Libre is only approved for use on the back of the arm. The sensor may not work properly if placed in other areas.

A new CGM called the Eversense system provides continuous 90-day blood glucose monitoring. But sales of the device stopped in 2020, partly because of the COVID-19 pandemic, but also because the device had to be implanted by a doctor.


FreeStyle Libre outperforms other FDA-approved CGMs such as Medtronic Guardian 3, Dexcom G6 and Eversense systems in terms of cost, availability and ease of use. The only downside is that the sensor can only be placed on the back of the arm.

Glucose monitor communicating with insulin pump


FreeStyle Libre is a continuous blood glucose monitoring system used to check blood sugar in people with diabetes. It consists of a waterproof sensor worn on the back of the arm and a separate reader that records glucose levels. The sensor is worn for 14 days and then replaced.

The Freestyle Libre System has proven effective in stabilizing blood sugar in diabetics while reducing the risk of A1C and hypoglycemic episodes. FreeStyle Libre, while effective, can be inaccurate after eating, exercising, or taking insulin, sometimes requiring a backup fingertip test. Severe dehydration can also affect results.

A 14-day sensor retails for about $85 for FreeStyle Libre 14-Day and about $130 for FreeStyle Libre 2. With insurance, the cost could drop to $0 for some people.

Frequently Asked Questions

  • What is FreeStyle Libre?

    FreeStyle Libre is a continuous glucose monitoring (CGM) device for people who need insulin to control their diabetes. FreeStyle Libre 14-Day is approved for use by those 18 and older, while FreeStyle Libre 2 is approved for use in adults and children 4 and older.

  • How does FreeStyle Libre work?

    The FreeStyle Libre consists of a single-use sensor and a separate receiver that can be attached to the skin on the back of the arm for up to 14 days. It regularly monitors glucose levels in the interstitial fluid surrounding the cells beneath the skin’s surface.

  • How much does FreeStyle Libre cost?

    For most people with private insurance, Medicare or Medicaid, FreeStyle Libre can cost between $0 and $65 per month. The most expensive aspect is the sensor, which costs $130 per month. For the uninsured, a manufacturer co-pay card can be used to reduce costs.

  • How accurate is FreeStyle Libre?

    According to a study published in the journal in 2019, the FreeStyle Libre system provided 92.8% accuracy diabetes.

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  • Where can I buy FreeStyle Libre?

    You can buy FreeStyle Libre online or at many pharmacies and supermarket pharmacies. Whether you have insurance or plan to pay out of pocket, you will need a prescription to buy the device.

  • Can diabetics use FreeStyle Libre?

    As convenient as FreeStyle Libre is, it may not be as accurate as traditional blood glucose monitoring. The sensors may also cause allergic dermatitis in some people. Talk to your doctor to see if FreeStyle Libre is right for you.

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  • Is there an alternative to FreeStyle Libre?

    In addition to FreeStyle Libre, there are three other continuous glucose monitoring devices approved by the Food and Drug Administration (FDA):

    • Dexcom G6 CGM: A skin sensor-based device for children 2 years and older
    • Eversense CGM: An implantable sensor device approved for use 18 years and older
    • Medtronic Guardian Connect: A skin-sensor-based device for 14- to 75-year-olds
  • How does FreeStyle Libre compare to similar devices?

    FreeStyle Libre is less expensive than Dexcom G6 and Medtronic Guardian Connect and does not require daily calibration. Instead of checking other devices every five minutes or more, it checks glucose levels every minute. On the downside, FreeStyle Libre 14-Day has no high/low blood sugar level alerts.

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