Dexcom G7 vs Libre 3: What to Choose in 2025

Introduction

In the US., the Dexcom G7 and the Libre 3 fall among the top continuous glucose monitoring systems (CGM systems). These smartphone-compatible CGM systems can be used with their specific readers or connected to compatible smartphones. Both fall under the category of real-time continuous glucose monitors (rtCGM); here, the real-time CGMs relate to the ones transmitting glucose data to the reader or your smartphone without you even touching the sensor or your receiving device.

When discussing Dexcom G7 VS Libre 3, major aspects one needs to ponder include MARD value, age requirements, life-span of the sensor, AID compatibility (if required), and more. This blog covers all these aspects and a bit more.

Feature Comparison of Libre 3 and Dexcom G7

1. Accuracy & Age Requirements

The accuracy of a CGM is measured by its mean absolute relative difference (MARD) percentage. The MARD value measures the percentage difference between blood glucose meter and continuous glucose meter results. The lower the difference, the better the accuracy.

While measuring the accuracy, this should be kept in mind that CGM manufacturing companies like Abbott or Dexcom suggest specific sites for the CGM sensors to be inserted. It is important to wear the sensor accordingly; otherwise, the accuracy may vary.

Dexcom G7: Suitable for individuals ages 2 and above, these sensors are designed to be inserted on the back of the upper arm. While in kids between the ages of 2 – 6, these sensors can be inserted on the upper buttocks, the company suggests the best accuracy on the back of the upper arm. These sensors have an MARD value of 8.2%.

Freestyle Libre 3: Suitable for individuals ages 4 and above, these sensors are designed to be inserted on the back of the upper arm. Abbott says, to ensure accurate results and functionality, it is crucial to apply these sensors on the back of the upper arm. These CGM sensors boast a MARD value of 7.8%.

2. Life-Span of the Dexcom G7 and Libre 3 Sensor

A Dexcom G7 sensor lasts up to 10 days and 12 hours (grace period). Once your sensor expires, the grace period shall start, giving you a chance to set up your new sensor in time and avoid waiting for warm-up time. Whereas, a Freestyle Libre 3 Sensor lasts for up to 14 days.

It should be kept in mind that, if inserted correctly, your sensor lasts the longest when it is applied/inserted following proper guidelines. Moreover, applying a CGM Patch keeps your sensor firmly attached, leaving no space for it to get loose.

3. AID Compatibility

Automatic Insulin Development (AID) compatibility is the ability of a CGM sensor to be integrated with an automatic insulin pump. Some of the CGM sensors are AID compatible, while others are not. Modern AID systems come with both options, auto insulin boluses (based on CGM readings) and manual insulin boluses, where the users can take boluses with just one touch on their smartphone’s screen.

Dexcom G7: This sensor is AID compatible. It can be connected to the most automatic insulin pumps, i.e., iLet Beta Bionics insulin pump, Omnipod 5, Tandem Mobi, and t: slim X2 insulin pump.

Freestyle Libre 3: The FreeStyle Libre 3 sensor is not compatible with any automated insulin delivery (AID) systems in the USA. Among Freestyle CGMs, the Libre 2 Plus and Libre 3 Plus are currently AID compatible.

4. Cost & User Experience

Abbot’s CGM is an excellent option for those who prefer a more discreet device. The sensor of the Freestyle Libre 3 is small and compact, measuring only 35mm x 16mm x 2mm. This allows it to be worn discreetly under clothing and can be less noticeable than other continuous glucose monitoring devices.

The Dexcom G7 receiver and Device bit slightly larger and may be more noticeable under clothing when worn on the body. Libre 3 is comparatively less expensive than the G7. The cost of the Freestyle Libre 3 sensor is around $99, while the cost of the Dexcom G7 sensor is around $350. Additionally, its reader is less expensive than the Dexcom.

More to Consider When Choosing a CGM Sensor:

Although continuous glucose monitors, whether Dexcom G7 or Freestyle Libre 3, simply monitor blood sugar and transmit the data over to the receiver or connected smartphone, understanding small differences can help you select the right CGM sensor.

Dexcom G7: Suitable for type 1, type 2, and even gestational diabetes. This sensor gives urgent low alerts 20 minutes before your blood sugar even goes down, thus, especially suitable for anyone with hypoglycemic conditions. The size of the transmitter installed CGM sensor is 27mm x 23mm x 4.7mm. The reader’s size is 93mm x 23mm x 12mm, and its battery lasts up to 7 days.

Freestyle Libre 3: Suitable for type 1, type 2, and gestational diabetes. With an approximate size of two stacked pennies, this is the tiniest yet most accurate sensor in the world. It has a diameter of 21mm and a height of 2.9mm. With 4 days of typical use, the Libre 3 reader size is 95 mm x 60 mm x 16 mm.

Dexcom G7 vs. FreeStyle Libre 3: Which Suits Best For You

Choosing the best continuous glucose monitor (CGM) in 2025 depends on your priorities, whether it’s accuracy, cost, size, or insulin pump integration. This comparison of the Dexcom G7 and FreeStyle Libre 3 highlights key features, benefits, and differences to help you decide which CGM suits your diabetes management needs.

FreeStyle Libre 3: Affordable and Discreet

The FreeStyle Libre 3 is a compact, budget-friendly CGM that delivers reliable glucose monitoring without the need for scanning, perfect for cost-conscious users who don’t require insulin pump integration.

Why Choose FreeStyle Libre 3?

• Cost-Effective: The FreeStyle Libre 3 is generally more affordable than the Dexcom G7, making it a great option for budget-conscious individuals managing diabetes.
• Compact and Discreet: Its small, lightweight design ensures comfort and discretion, ideal for users who prefer a low-profile CGM sensor.
• Real-Time Glucose Monitoring: No scanning required—get continuous glucose readings and alerts directly on your smartphone for convenient diabetes tracking.
• Algorithm Interoperability: While it lacks US insulin pump connectivity, the Libre 3 supports algorithm-based diabetes management tools for non-pump users.

Note: The FreeStyle Libre 3 may experience occasional accuracy issues compared to the Dexcom G7, particularly during rapid glucose fluctuations.

Best for: Users seeking an affordable, discreet CGM with real-time data and no need for insulin pump integration in the US.

Dexcom G7: Best for Accuracy and Insulin Pump Integration

The Dexcom G7 stands out for its exceptional accuracy and seamless integration with insulin pumps, making it ideal for users seeking advanced diabetes management.

Why Choose Dexcom G7?

• Advanced Features: Offers robust data-sharing capabilities and compatibility with smartphones and smartwatches for real-time glucose monitoring.
• Insulin Pump Connectivity: The G7 integrates with insulin pumps for automated, closed-loop insulin delivery, streamlining diabetes management for pump users.
• Unmatched Accuracy: With a lower Mean Absolute Relative Difference (MARD) compared to the FreeStyle Libre 3, the Dexcom G7 delivers precise glucose readings, especially during rapid glucose changes. This makes it a top choice for reliable diabetes monitoring.
• Fast Alerts and Data Access: The Dexcom G7 enables treatment decisions within just 11.5 hours of sensor wear, providing quick, real-time glucose alerts and data for proactive decision-making.

Best for: Users prioritizing accuracy, insulin pump integration, and fast, reliable alerts for effective diabetes management.

Conclusion

While discussing Dexcom G7 versus Libre 3, it should be kept in mind that the selection of either depends on your requirements. In case you suffer from extremely low blood sugar levels (hypoglycemia), going for the Dexcom G7 may be a better option, since it gives you low glucose alerts 20 minutes before it even goes down. While people who prefer better accuracy or a longer lifespan may go towards the Freestyle Libre 3.

Frequently Asked Questions