Dexcom G6 vs Dexcom G7: CGM for Non-Diabetics
Evaluating Dexcom’s newest continuous glucose monitor: a comparison of tech, comfort, and usability.
There are many, many comparisons of these two devices but most are for those with Type 1 or Type 2 diabetes. This comparison is specifically for those with fully-functioning pancreases.
Preface: This is a follow up to my previous article comparing the FreeStyle Libre andDexcom G6.
The Sensors
Size
The most notable difference between the two sensors is size. The Dexcom G6 is much longer and significantly thicker than the G7 — primarily due to the fact that the G6 is a 2-piece device, while the G7 is an all-in-one.
Application
I was surprisingly intimidated by the G6. I watched many application videos before the first time I attempted to apply it. The applicator is large and the adhesive around the sensor is very wide, so there is little room for error.
Before you apply your sensor, you first have to note a sensor code on the adhesive sticker, peel it off, and save before application. The applicator also has a safety tab, which you remove before applying.
Once, the sensor is applied, you must insert the transmitter into the sensor and make sure it’s paired with the app. It’s very involved.
The G7 application was surprisingly reminiscent of the Abbott Freestyle Libre. It felt as if the Libre and the G6 had a child. Application was pretty straightforward: unscrew the lid, apply to skin, push the button. Voila!
Dexcom recommends placing both the G6 and G7 on either the abdomen, back of the upper arm, or the buttocks. Most people prefer the upper arm location.
Dexcom does provide additional adhesive for the G7, and they strongly recommend you apply it over the sensor. I can see why. However, it’s not the easiest to apply or to apply without wrinkles. See below.
As a person with smaller arms, I much prefer the size of the G7 over the G6. It’s easy to forget you’re wearing it and more difficult to snag on things because of the decreased thickness. It’s also a one-piece application, which is a vast improvement.
Both should be worn with a cover to protect the sensors. However, I learned a valuable lesson with both: You need to use something like this to put in between the adhesive of the sensor and the adhesive of the cover. I tried to remove the cover after about 5 days of sensor usage and ripped my entire G7 sensor off. Womp womp…
Warmup Period
The G6 has a warmup period of 2 hours vs the G7, which has a warmup period of only 30 minutes!
Data Transmission and Storage
The G6 and G7 both use Bluetooth.
The G6 uses a transmitter that is inserted on top of the sensor to transmit data to your phone every 5 minutes. It has a sensor memory of 3 hours (which can be an issue for those with overnight Airplane Mode preferences).
The G7 has a built-in transmitter that transmits data to your phone every 5 minutes. It has a sensor memory of 24 hours.
Replacement Frequency
The G6 and G7 both must be replaced every 10 days. The G6’s transmitter needs to be replaced every 90 days.
Accuracy
Both sensors are very accurate. The G6 has an overall MARD score of 9% and the G7 has an overall MARD score of 8.2%. The lower the MARD score, the better.
Calibration
Both the G6 and G7 will let you calibrate your sensor with a finger stick. However, the sensor code that comes with the sensors is Dexcom’s way of calibrating. If you lose the code, you can calibrate your sensor with 2 finger sticks.
The Apps
Dexcom G6 App
G6 app is quite bare bones. While there is a chart to show your glucose, there’s not a lot else in terms of data. HOWEVER, Dexcom has a separate app for this called Dexcom Clarity, available on iOS, Android, and the web! We’ll go over that in a bit. The G6 App does, of course, have a way to calibrate the sensor. It also has a similar way to add a log — called an “event” for carbs, exercise, health, and insulin. This is the most basic of logging functionality.
Other less-notable features are “share” (to share your data with a “follower” via email) and adding a dependent account (which is helpful if you have dependents who are also using a G6.
Let’s talk about alerts. Do you want alerts?! Do you want them at ALL hours of the night as LOUD AS HUMANLY POSSIBLE?! Look no further than the G6 app! In Dexcom’s defense, they have built this app specifically for diabetics and these alerts are life-saving, so please understand that I say this only in jest. But for the love of all that is holy, please make sure to tweak those alert settings before your first night with this sensor.
Fun fact: the G6 app has an Apple Watch app and complication. However, it is only updated every 15 mins or so or until you tap on the complication or open the watch app.
The G6 app also works equally well on both iOS and Android!
Dexcom G7 App
Though very similar to the G6 app, the G7 app has had a face lift and also kind of integrates more with Dexcom Clarity. The Clarity data summary (Clarity card) now lives on the home screen. Helpful but more on Clarity below.
One of the things I love most about the G7 app is the improved alerts customization. No more midnight heart attacks because you fell asleep on your sensor!
The G7 app is available on both iOS and Android.
Dexcom Clarity
Though Dexcom has given a nod to Clarity in its G7 app, transparently, I have mostly used the web version as I find it easier to sift through data on a larger screen. Below are some screenshots of the web version’s functionality.
Conclusion
For a non-diabetic, both of these sensors are great. The G7 is smaller, easier to apply and is more of a 1-step system than the G6. For a beginner, I would recommend the G7. If you’re looking for a slightly more-accurate device, I would pick the G7. And in terms of app design, the G7 is a big improvement. If you find it difficult to get the G7, the G6 will hold you over for now.
If you’re curious about a few of the companies with apps that work with the Dexcom sensors, I wrote an article about them, and I plan on writing about several more in the future, so stay tuned!
