Dexcom G7 vs. FreeStyle Libre 3: A CGM Comparison
For thousands of people living with Type 1 and Type 2 diabetes, the advent of continuous glucose monitoring (CGM) has been a life-changing breakthrough. These remarkable advancements in diabetes care not only provide real-time accuracy and efficiency in blood sugar monitoring but also eliminate the need for the daily finger pricks that traditional testing requires, offering a new sense of hope and optimism.
But is a CGM system right for you? If so, which one? First off, it's crucial to understand that all continuous glucose monitoring devices require a doctor’s prescription. So, you’ll need your physician’s approval and guidance, no matter which one you try, to ensure you're on the right path for your diabetes management.
There are two leading brands in the CGM universe, Dexcom and FreeStyle, and both have recent introductions that are enhancing performance and empowering users with even greater blood sugar control, putting the power back in your hands.
They are the Dexcom G7 and the FreeStyle Libre 3.
In this post, we’ll compare and contrast these state-of-the-art CGM systems and, hopefully, provide you with some helpful information you can use to begin a discussion with your diabetes physician. Let’s start with what’s most important to anyone with diabetes – blood sugar accuracy.
Understanding CGM Accuracy: What is MARD (Mean Absolute Relative Difference)?
MARD is a measurement written in a percentage that shows a CGM’s accuracy. The percentage is how far off, on average, the readings of a CGM are against those of a blood glucose meter. So, the smaller the percentage, the greater the accuracy of the CGM. Here’s the thing: you’ll find different MARDs advertised for both the Dexcom G7 and the FreeStyle Libre 3, depending on what source you examine. That being said, the G7 is widely regarded as having a MARD value of around 8.2%, while the Libre 3 has a MARD in the neighborhood of 7.9%.
Based on these numbers, the Libre 3 has a slight edge in accuracy. However, the difference is so negligible that there is no way to be sure one of these devices is more accurate. We can tell you that both the Dexcom G7 and the FreeStyle Libre 3 are darn accurate CGMs.
Glucose Reading Frequency: How Often Do Dexcom G7 and Libre 3 Update?
Now, we’re starting to get into some important differences. Both of these devices provide real-time blood sugar monitoring that is automatically sent from a remote sensor to a smartphone application. With the FreeStyle Libre 3, blood sugar data is transmitted every minute, offering more up-to-the-minute coverage. With the Dexcom G7, it happens every 5 minutes. The frequency of these readings could potentially impact your diabetes management, a point worth discussing with your endocrinologist.
Sensor Specifications and Features: Dexcom G7 vs. FreeStyle Libre 3
If size matters, the FreeStyle Libre 3 has the smallest and most discreet sensor on the market (The Libre 3 Plus). It’s about the size of two stacked pennies. The Dexcom G7 sensor, while certainly not obtrusive, is a bit larger and about 1.5x as thick as that of the Libre 3.
There’s another key difference. The Libre 3 Plus can remain on your arm for up to 15 days. You’ll have to replace the G7 sensor in 10 days, though there is a 12-hour grace period after the ten days is up for your convenience. The Libre 3 Plus does not have a grace period for replacement.
The Libre 3 Plus is applied quickly and easily using a one-piece applicator. The G7 requires an over-patch to hold the sensor firmly in place. The G7, however, offers the option of wearing the sensor on the abdomen for added discretion. The Libre 3 Plus must be worn on the upper arm.
Blood Sugar Alerts: Which CGM Offers Better Notifications?
Both CGM systems offer alerts that can immediately make you aware of sudden drops or spikes in blood sugar. The Libre 3 alerts are based on readings every minute, while the Dexcom G7 can alert you based on readings every 5 minutes. The G7, however, provides for more robust personalization regarding alerts and has an innovative “predictive low” alert that can let you know an urgent low is coming up to 20 minutes before it happens.
Sensor Warmup Period: How Long Until You Get Real-Time Readings?
Another significant difference in favor of the G7 is how long it takes a newly applied sensor to warm up and be ready to deliver those real-time blood glucose readings. A Dexcom G7 sensor is ready to go just 30 minutes after application. You’re looking at a 60-minute warmup time with the FreeStyle Libre 3 Plus sensor.
Insulin Pump Compatibility: Which CGM Works with Your Pump?
The Dexcom G7 is approved by the Food & Drug Administration (FDA) to integrate with Tandem insulin pumps and Omnipod 5 patches for seamless diabetes management. Abbott, makers of the FreeStyle Libre 3, has established integration partnerships with Tandem, but approval is still pending.
CGM Sensor Prices & Insurance
Since you are going to replace sensors every 10-15 days, they are the costliest part of a CGM solution. We found no substantial cost difference between G7 sensors and Libre 3 Plus sensors. In fact, both are available online for $139.99 from Diabetic Warehouse, a leading online supplier of diabetic supplies at affordable costs. However, it's important to consider your insurance coverage, as this could significantly impact the overall cost of using a CGM.
Dexcom G7 vs. FreeStyle Libre 3: A Quick Comparison
| Feature | Dexcom G7 | FreeStyle Libre 3 |
|---|---|---|
| Accuracy (MARD) | 8.2% | 7.9% |
| Reading Frequency | 5 minutes | 1 minute |
| Sensor Size | 24mm x 27.3mm x 4.6mm | Two stacked pennies |
| Sensor Lifespan | 10 days | 15 days |
| Sensor Warmup Period | 30 minutes | 60 minutes |
| Insulin Pump Integration | Yes | Not Yet |
| High/Low Alerts | Personalized/Predictive | Standard |
| Body Location | Upper Arm or Abdomen | Back of Upper Arm |
| Bluetooth Range | 33 feet | 33 feet |
| Smartphone Compatibility | Apple/Android | Apple/Android |
Conclusion
Both the Dexcom G7 and FreeStyle Libre 3 are excellent CGM systems that can help improve blood sugar control. The choice depends on your personal needs, preferences, and your doctor’s advice. Talk with your endocrinologist or diabetes physician to find out which one is right for you.
At Diabetic Warehouse, we’re committed to helping those with diabetes manage blood sugar with a complete selection of testing and treatment supplies at up to 65% less than those found at most pharmacies and suppliers.
