FreeStyle Libre 2 Vs. FreeStyle Libre 3: What Is The Difference?

Answer

Thanks for reaching out to us! The Freestyle Libre continuous glucose monitor (CGM) is now in its third generation, with the most recent FreeStyle Libre 3 being announced in May 2022. Although similar to the FreeStyle Libre 2, there are some key differences, which I discuss in the sections below.

Overall, the main differences are:

• Size of the sensors
• Smartphone connectivity
• Accuracy

Size Difference

First and foremost, there is a considerable size difference between the sensors for the FreeStyle Libre 2 and FreeStyle Libre 3.

Touted as 'the world's smallest, thinnest glucose sensor', the FreeStyle Libre 3 sensor is approximately the size of two stacked U.S. pennies. This is compared to the FreeStyle Libre 2 sensors, which are about the size of two U.S. quarters stacked on top of one another.

Abbott, the manufacturer of FreeStyle products, states that the FreeStyle Libre 3 reduces the sensor's total volume by more than 70% compared to FreeStyle Libre 2 sensors. The weight of the sensors has also significantly decreased.

The specific dimensions for the sensors are as follows:

• FreeStyle Libre 2 Sensor: 35 mm x 5 mm (weight 5 grams)
• FreeStyle Libre 3 Sensor: 21mm x 2.9mm (weight 1.1 grams)

A smaller sensor is certainly less cumbersome to use and wear, so is definitely one of the most positive features of the new monitor.

Smartphone Connectivity

Another feature of the FreeStyle Libre 3 that is a significant change from the FreeStyle Libre 2 is that it doesn’t require a separate reader device, and uses a smartphone as the reader instead. The FreeStyle Libre 2 required scanning with a separate reader or smartphone to display results.

The FreeStyle Libre 3 also now sends real-time glucose readings automatically to a person's smartphone, every minute.

Additionally, the Bluetooth range of FreeStyle Libre 3 is greater, with the ability for your phone to connect to the sensor up to 33 feet away (this is compared to the 20-foot range of the FreeStyle Libre 2).

Accuracy

Abbott has long reported that their FreeStyle Libre devices are the most accurate when compared to the other continuous glucose monitors on the market (e.g. Dexcom systems, Guardian Connect, etc.).

They report this based on studies showing that Freestyle Libre monitors have the lowest 'mean absolute relative difference (MARD)' among all of the currently available monitors.

The 'MARD' is essentially a measure of the error between what your meter reads and the actual blood glucose value (sometimes referred to as the 'reference' value). The smaller the value here, the better (i.e., a small percentage indicates that the meter readings are close to the reference glucose value, while a larger MARD percentage indicates greater discrepancies between the meter and reference glucose values).

Abbott reports the 'MARD' for the FreeStyle Libre 3 system is 7.9%, making it the most accurate 14-day continuous glucose monitor. In fact, it is the first CGM to demonstrate a MARD of less than 8%.

Cost And Coverage

I wanted to add this section as cost and insurance coverage are common questions that come up with continuous glucose monitors. There is essentially no difference currently in cost between the FreeStyle Libre 2 and FreeStyle Libre 3.

The FreeStyle Libre 3 costs about $120/month for 2 sensors, the same as the Libre 2. Insurance coverage (and prior authorization requirements) are thought to be the same as well between the two monitors.

It is possible that it may take your insurance company a few weeks/months to update their formulary to add on the FreeStyle Libre 3, but if you previously had the Libre 2 covered, there is a good chance the Libre 3 monitor will be covered as well.

However, if another continuous glucose monitor (e.g. Dexcom) is preferred on your plan over the FreeStyle, I imagine this would continue to stay the same.

Final Words

Thanks so much for reaching out to us! I hope this breakdown was helpful. Please let us know if you have any other questions about these continuous glucose monitors and if anything else comes up, please reach out!