The Dexcom G6 is the most advanced model currently available from market-leading continuous glucose monitor (CGM) company Dexcom based in San Diego, California.

A first-of-its-kind offering that brought a new form factor to this CGM, it offers direct-to-mobile app connectivity without a need to carry a separate receiver. Also, the Food and Drug Administration (FDA) determined this device is accurate enough to NOT require regular fingerstick glucose tests to calibrate the system.

Even if you’re not personally familiar with this impactful and popular diabetes device, you may have seen TV commercials for it, or heard about Dexcom’s Super Bowl ad in February 2021 featuring celebrity singer-actor Nick Jonas (who lives with type 1 diabetes himself and uses Dexcom’s product).

If you’re curious about the Dexcom G6, you’re in the right place to find out everything you need to know!

First cleared by the FDA in March 2018, the G6 was the first-ever CGM to offer direct-to-smartphone app connectivity without requiring a separate receiver, although users can still opt to use one or the other. It was also the first to do away with the requirement to take fingerstick tests to calibrate for accuracy.

Here’s breakdown of what the system entails:

Transmitter. This is the thin gray part that clicks on top of the sensor casing worn on the body. It functions like the brain of the system. The G6 transmitter is a third smaller, thinner, and lower-profile than the previous model. It has a 3-month battery life. With built-in Bluetooth connectivity, the G6 sends results every 5 minutes directly to a smartphone app, a separate receiver, or to compatible devices within 20 feet.

No fingersticks required. The G6 does not require once or twice-a-day calibrations as previous versions did. That means it has a non-adjunctive designation from the FDA, so it can be used in making insulin dosing and treatment decisions without a backup fingerstick test. What’s awesome is that even though the G6 is factory-calibrated, Dexcom has built in the capability for users to still enter calibrations manually if they choose to do so (for extra confidence in accuracy).

Disposable auto-inserter. The G6 offered a whole new inserter design for the first time in many years. It’s a plastic, spring-loaded self-contained auto-applicator that requires you to do nothing but press an orange button to inject a new sensor. It’s even good for one-handed insertions! The sensors come in boxes of three, pre-assembled into the auto-inserter, so no needles are exposed. To insert, you pull the adhesive backing, place the unit on your skin, and push the button. The disposal applicator piece will automatically separate from the sensor once it’s on your body.

Sensor code. But there’s more! Each Dexcom G6 sensor has a four-number code printed on that adhesive backing that you peel off before attaching the sensor to your body. You need to enter that code into the mobile app or separate receiver device just prior to insertion, which triggers the “no calibration” functionality. Note that if this code is not scanned or entered, the sensor will require the daily calibrations every 12 hours, as was required with the G5 model.

10-day wear. The water-resistant G6 sensor is said to be more accurate and reliable, and can be worn for 10 days compared to the previous 7 days.There is now a hard-shutoff at the 10-day mark, meaning you won’t be able to extend the sensor for prolonged wear, as many people did with previous versions. The FDA actually laid this out in a letter to Dexcom describing requirements for the G6. There are some Do-It-Yourself methods to restart a sensor, but those are considered “off-label” and not endorsed by the FDA.

Young kids. The Dexcom G6 is approved for ages 2 and older.

Goodbye, Tylenol effect. No more interference from medications containing acetaminophen (Tylenol), which has been an ongoing issue in the CGM world. The G6 has a special membrane on each sensor that eliminates the body chemistry interference from these medications, which previously could give false high glucose results.

Mobile app. After a 2-hour warmup period without any data, the G6 mobile app starts showing glucose results. It displays a circle with the current real-time glucose level and appropriate Gray/Red/Yellow color code depending on whether you’re In Range, Low or High. A little arrow points in the direction you’re trending, and the graph with glucose value dots and other inputted data like insulin/carbs/exercise is displayed below that. Want to view more than the past 3 hours of CGM data? Turn your smartphone horizontally to see up to 24 hours of data and scroll back accordingly. Data can be shared via the separate Dexcom Follow app with as many as 10 people, and with a doctor’s office through the Dexcom Clarity platform.

Predictive alerts. You’ll get an “Urgent Low Soon” alert whenever the sensor picks up that glucose levels are falling fast and predicts you’ll drop to 55 mg/dL within 20 minutes. This alert is required by the FDA and cannot be turned off, unlike the other G6 alerts and alarms that can all be silenced.

Customizable alerts. You can set different alert preferences for times of day or night. There’s a “Do Not Disturb” feature for audible or vibration alerts, though the “Snooze” feature is disabled on important alerts like “Urgent Low” and “Sensor/Transmitter Failure.”

Both iOS and Android. The G6 app works with both Apple and Android, but not with every model. Here’s a list of specific compatible devices, although it’s not entirely clear which devices or wearables are seamlessly compatible from the get-go. Also, Dexcom says the G6 won’t yet send data directly to an Apple or Android watch without the phone.

See this nifty G6 simulator app available on both iTunes and Google Play to take the Dexcom G6 app for a trial run.

The standard measurement of CGM performance is known as the mean absolute relative difference (MARD). With this measure, the lower the number, the better the accuracy. Clinical data for the Dexcom G6 shows it has a MARD of 9 percent with sustained accuracy over the time a sensor is worn. That puts it ahead of all its direct competitors.

However, individual users’ experiences may vary, and many people who’ve used both the Dexcom G6 and Abbott FreeStyle Libre 2 report comparable accuracy.

To view glucose data trends and send reports to your healthcare providers, you’ll want to use Dexcom CLARITY, the company’s web-based software available to customers at no cost both online and through the Dexcom G6 smartphone app.

On the G6 app, you simply turn the orientation of your smartphone to horizontal view, and you’ll see a green icon with four vertical lines in the upper right corner. Clicking on that icon takes you directly to the Dexcom CLARITY app.

CLARITY shows your average glucose for any number of different days, reports for the past 24 hours to 3 months, and comparison charts to help you see how you managed during different periods. For example, if you started on a new insulin pump a month ago, you can easily view how your CGM data for the past month may differ from the weeks or months prior.

Two other popular features of CLARITY include:

  • Time in Range view: shows the percentage of time that your glucose levels are in low, target and high ranges. The default “in-target” range is 70-180 mg/dL, which may not be what you set for your CGM, so you can change the Dexcom CLARITY ranges in Settings to your preferred targets.
  • Glucose Management Indicator (GMI): this approximates the laboratory A1C result you might expect, based on your average glucose from the most recent 12 days of CGM data. This isn’t a precise prediction, but many use this feature to help them get a better idea where they stand on that three-month average result.

You can also grant access to your CLARITY data to your healthcare clinic or doctor’s practice. You simply authorize this via the app or on the CLARITY website, which allows them to login at no cost and view your data. Notably, using the CLARITY overview report is billable to insurance, so your doctors can get reimbursed for interpreting and reviewing your CGM data, through Medicare or private insurers. The billing code (aka CPT code) is 95251.

Dexcom CGMs are covered by a large array of private insurers in the United States. As of fall 2020, Medicare does cover the Dexcom G6, as well.

Of course, benefits vary by plan, so you’ll need to check with yours. Just remember that you’ll need a prescription for the G6 transmitter as well as the box of sensors, so you’ll have to work with a healthcare professional before purchasing.

Until spring 2021, Dexcom sold their systems and supplies directly via their website. But they now work with distributors like Edgepark for online ordering.

Short answer: The Dexcom G6 is a great tool for any adult or child with any type of diabetes, including those who are pregnant or diagnosed with gestational diabetes, given how important tight glucose management is during pregnancy.

The benefits of CGM use are well-documented:

  • helps avoid severe high or low blood sugars, especially immediately dangerous hypoglycemic events
  • helps guide insulin dosing and safeguard users from suffering mistakes
  • sense of safety and security for those who don’t feel dangerous lows coming on (hypoglycemia unawareness)
  • increased glucose “time in range” for better diabetes control
  • lets users see and learn from the direct impact of their food and physical activity on their body

In fact, CGM is so powerful for improving overall health outcomes that it’s quickly becoming a consumer wellness product.

There’s little doubt that all people with diabetes can benefit, but recent studies show that CGMs may be especially beneficial for the groups that tend to wear them the least — teens, young adults, and older adults.

When the FDA approved the G6 in 2018, the agency created a brand-new category of device that it refers to as “iCGM,” or Integrated CGM — a system designed to connect directly with other compatible devices, such as a smartphone, insulin pump, or other wearable.

Devices that currently work the Dexcom G6 include the latest Omnipod tubeless insulin pump, as well as the tubed Tandem t:slim X2 insulin pump with Basal-IQ and Control-IQ closed loop features. Not sure whether your device is compatible with Dexcom G6? You can check that out here.

What’s exciting is that the future Dexcom G7 model will have even more advanced features, and integration with automated diabetes management systems.

Based on customer reviews from consumer sites like the Better Business Bureau and Trustpilot, people are generally satisfied with the Dexcom G6 and find that it helps them improve and manage their glucose levels. The most common complaints are those relating to customer service, insurance claims, and deliveries.

Many online reviewers say the Dexcom G6 is extremely reliable and accurate, however others report finding that the transmitters do not always last the full 90 days and sensors also fail early before the full 10 days.

As a result, a common gripe is having to spend a lot of time contacting Dexcom’s technical support, either by phone, text or online, to get a replacement sensor sent to them within 3 to 5 days.

DiabetesMine’s own founder and editor Amy Tenderich was an early user of the G6 model, and described the accuracy as “astoundingly good.” She reported fewer lost connections in comparison to the previous CGM generation. She also noted that her sensors sometimes irritated the skin, or peeled off too soon, due to the adhesive used.

Personally, I have found the Dexcom G6 to be accurate and helpful — when it keeps working as it should. Often, my G6 sensors fail after 5 to 6 days, so I only get about half the use time I’m due.

A real life-changer is the “Urgent Low Glucose” predictive alert that lets me know when I’m going to cross the threshold of 55 mg/dL in the next 20 minutes. Knowing ahead of time means I can take action before crashing into a dangerous low.

Also, the redesigned auto-inserters make it so much easier to insert a new sensor by myself, single-handed. The older G4/G5 inserter was described by some as a “harpoon,” whereas it’s rare to see users complaining about pain with the G6 inserter. But for me, the larger bulkier size of this new applicator is a bummer because I can’t just toss it into my homemade sharps containers like I could with the older, thin sensor devices.

Some user tips that seem to be floated most often for the G6:

  • Make sure you’re hydrated, in order to ensure better glucose data and sensor reliability.
  • Use some nasal allergy spray on your skin and a medical adhesive wipe to prepare for insertion. This helps avoid skin irritation and keep the sensor on longer.
  • Even though you can enter fingersticks to calibrate the G6, it’s not required, and entering multiple results in a short period of time can cause the CGM to get confused. Wait at least 30 minutes if it loses a signal or is trying to recalculate your glucose levels, to see if it can re-establish a solid connection with accurate data.

There are several other CGM systems on the market that are similar to the Dexcom G6. Here are a few to consider:

  • Medtronic’s Minimed Guardian Connect. This stand-alone CGM sends updates, notifications, and predictions to your smartphone. Like the Dexcom, it can help stabilize glucose levels. But it is only approved for 7-day wear, and many users say the sensor is less comfortable on the body. This device is FDA-approved for people with diabetes ages 17 to 75.
  • FreeStyle Libre by Abbott. This is a “flash glucose monitor” that consists of a little white circular sensor worn on your upper arm. You have to manually scan the sensor each time you want a reading, using a handheld receiver or smartphone app. The latest Libre 2 version offers 14-day wear and optional alerts for low and high glucose levels. The FDA has approved this device for kids as young as 4 years old.
  • Eversense by Senseonics. This is a tiny sensor that’s implanted under the skin in your upper arm. You wear a transmitter over the insertion spot on your arm, which streams glucose data continuously to your smartphone. This requires a doctor’s office visit to insert and remove each sensor, and some people find that they incur small scars on their arm from the procedure. This long-term option is approved for 90-day wear in the United States and 180-day wear in Europe. It is currently FDA-approved for people 18 and up.

The Dexcom G6 is the latest and most popular CGM on the market from a company that’s been developing CGM technology for nearly 20 years.

It offers real-time glucose data, complete with a range of alarms and customizable alerts to predict dangerous out-of-range glucose levels, and also allows for more proactive diabetes management.

With its easy-to-use form factor, high accuracy ratings, and compatibility with other diabetes devices, the Dexcom G6 can be an excellent choice for anyone with diabetes to consider. However, it can be quite costly as well as frustrating when the product doesn’t deliver as promised.