We’ve come a long way in continuous glucose monitoring (CGM) technology since it first hit the market over two decades ago, and San Diego-based Dexcom has been leading the way on innovation for most of that time.

Since the launch of its initial 3-day sensor in 2006, Dexcom has helped shape how the U.S. Food and Drug Administration (FDA) views this tech and forged new paths in providing more options for people to keep tabs on their blood sugars with a quick glance at a receiver, mobile app, or smartwatch.

Dexcom is not the only CGM maker, and it wasn’t the first — Medtronic launched the first-ever CGM way back in 1999. But from its earliest model to the latest mobile connected device, Dexcom has cemented its spot as the most popular full-featured CGM available.

Everything changes quickly in the diabetes device universe, so it’s important to keep tabs on what the company is up to. Here’s a deep dive into what Dexcom is offering in 2020 and beyond, along with a bit of its rich history.

What is CGM?

If you’re not familiar with CGM systems, read our guide here.

In short, a CGM consists of a small sensor inserted under the skin on your abdomen that takes glucose readings every few minutes. The disposable sensor is worn for a week or more at a time, and is connected to a small, reusable transmitter allowing it to wirelessly send readings to a device for display. Early CGMs relied on a dedicated monitor, but most now display the data via a smartphone app, eliminating the need for users to carry around an extra device.

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Dexcom G6

Approved for ages 2 and older and launched in 2018, the Dexcom G6 was the first CGM to offer direct-to-smartphone connectivity, with no need for a separate receiver and no fingerstick calibrations required.

10-Day Wear Sensor: The water-resistant G6 sensor is said to be more accurate and reliable than earlier models, and can be worn for 10 days compared to the previous 7 days.But the caveat is that there’s a hard-shutoff at the 10-day mark, meaning users can no longer extend the sensor for prolonged wear, as many users previously did.

The FDA actually laid out this restriction in a letter to Dexcom describing requirements for the G6, with a specific clause mandating that the disposable sensor must shut off and be incapable of use beyond the approved 10 days of wear.

Transmitter: The G6 transmitter (the brain of the system) is about a third smaller, thinner, and lower-profile than the previous model and has a new glucose-analyzing algorithm inside. It has a 3-month battery life that also includes a brief grace period at the tail end but starts providing notifications when the 90-day cycle is near and/or when the battery is nearing its end.

No ‘Required’ Fingerstick: The FDA has approved the G6 as accurate enough to rely on for making insulin dosing and treatment decisions without a backup fingerstick test, as was previously required. Users concerned about accuracy can still enter calibrations, if they wish.

Disposable Auto Inserter: With the G6, Dexcom introduced a new plastic, spring-loaded self-contained auto insertion device that requires nothing but the press of an orange button to inject a new sensor — even single-handed! G6 sensors come packaged in a box of three, with each sensor pre-assembled into the auto inserter so no needles are exposed. You simply pull off a sticky tab to reveal the sensor and the scannable connection code, and then after pushing the button to insert the sensor on your body, you dispose of the applicator.

Receiver Not Required: The G6 does still work with the touchscreen receiver introduced a few years earlier, but it’s no longer required by the FDA as part of the system. Many users simply rely on the G6 smartphone app to see CGM data and get alerts.

G6 Mobile App: This app works on both iPhone and Android. After a 2-hour warmup period without any data, the app starts showing glucose results. It displays a circle with the current real-time glucose level and appropriate Gray, Red, or Yellow color code depending on whether you’re In Range, Low, or High, respectively. A small arrow points in the direction you’re trending and a graph with glucose value and other inputted data like insulin, carbs, and exercise are displayed beneath. You can turn your smartphone horizontally to see up to 24 hours of data and scroll back accordingly. Of course, data can be shared with as many as five people via the separate Dexcom Follow app and with a doctor’s office through the Dexcom Clarity platform.

Alerts: With the G6, Dexcom added predictive alerts, meaning you’ll get an “Urgent Low Soon” alert whenever the sensor picks up that you’ll drop to 55 mg/dL within 20 minutes. Additionally, you can customize alerts for different 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.”

Goodbye, Tylenol Effect: With this model, Dexcom was able to eliminate 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.

Smartwatch connectivity

Yes, the G6 does connect to the Apple Watch to display CGM data and offers alerts and alarms on various watch faces.

But note that you must have the CGM connected to a compatible smartphone in order to have the data shared. That means you’re required to carry a smartphone as the bridge between the CGM and smartwatch, so if you go out but leave your iPhone at home, the Apple Watch and G6 won’t communicate with each other.

Dexcom has been promising a direct-to-watch capability for years, but it hasn’t yet materialized. Arguably, there is a lot that goes into that, including ensuring that any iOS watch updates don’t interfere with the data.

As we move into the final months of 2020, many are waiting anxiously for Dexcom’s next-gen tech that promises a slew of much-anticipated new features. Here’s what’s coming.

Dexcom G7

The G7 model has been in the works for several years as a collaboration with Verily (formerly Google Life Sciences). While details are still scant, Dexcom’s hinted at some big revisions to what the G7 will offer once it’s available in early 2021:

Extended Wear of 14 to 15 days: This adds 4 to 5 additional days compared to the current 10-day wear. As with the G6, no fingerstick calibrations will be required.

Fully Disposable: Unlike Dexcom CGM models to date, the G7 will be fully disposable. This means there will no longer be a separate transmitter with a 3-month battery life. Instead, the sensor and transmitter will be integrated, and once the sensor’s run is finished, you’ll dispose of the whole combined unit.

Thinner: Dexcom says the G7 will be the thinnest generation of its CGM sensors yet, but the company hasn’t yet released any specific detail on measurements or design.

Decision-Support: Dexcom has talked a lot about wanting to integrate software features like dosing assistance and information and prompts that help users make better health choices based on their CGM readings. Given Dexcom’s acquisition of TypeZero Technologies in 2018, they seem to be on the path to providing a smart algorithm for this kind of user support. This should also help the company in its goal to expand CGM use for more type 2s, as well as for users without diabetes.

As the diabetes device industry works toward connected “artificial pancreas” systems, the FDA has created an entire pathway toward interoperability, or the idea of “plug and play” that allows various CGMs, insulin pumps, insulin pens, and controlling algorithms to work together in a modular fashion.

The Dexcom G6 was first to obtain the FDA’s new “iCGM” designation, meaning it’s approved for use with similar devices that have a comparable interoperability designation — like Tandem’s t:slim X2 insulin pump.

Dexcom now works with several devices, from the Tandem pump to the Omnipod tubeless patch pump and InPen smart insulin pen from Companion Medical. The company also has more partnerships with different diabetes data platforms than any of its competitors.

Dexcom has also been a catalyst to the emerging Do-It-Yourself diabetes technology community. It was Dexcom’s CGM tech that served as the basis for a surge of grassroots innovation that crystallized at the #WeAreNotWaiting movement in 2013.

A small group of enterprising DIYers figured out a way to set up open-source data platforms to bypass the Dexcom limitations at the time. In doing so, they created the data-sharing platform known as Nightscout and an entire online community of DIY data-sharers; eventually, that evolved into an open-source closed loop system, as well.

Dexcom wasn’t a fan at the start, and leadership dubbed the DIYers “rogue cowboys.” The moniker stuck and emboldened the #WeAreNotWaiting community even more.

Over the years Dexcom has come to embrace this movement, even launching a developer platform to further fuel innovation based on its core technology in 2017.

While the previous G4 and G5 versions were officially discontinued in June 2020, you’ll still likely find users out there holding onto these older models.

G4 Platinum

The G4 was launched in 2012 and brought with it a new iPod-style receiver device that was much sleeker and more modern-looking than anything else in CGM technology at the time. It was first FDA-approved for use by adults 18 and older, and then two years later was OK’d for kids and teens. In early 2015, Dexcom introduced a new receiver that could “share” data with a small number of followers, introducing Dexcom Share and the Follow apps for the first time.

G5 Mobile

In late 2015, Dexcom introduced the G5 and with it, a new age of built-in data-sharing capability that, for the first time, allowed data to be displayed on a mobile app rather than just a standalone receiver device. The G5 still used the iPod-style receiver for the first couple of years, until Dexcom launched its new touchscreen receiver with a vertical orientation.

When Dexcom discontinued the G4 and G5 in June 2020, many users were forced to upgrade to the G6. Since most people — including those on Medicare — are now able to access the G6, chances are it will soon become quite challenging to find supplies for these older models.

As a flashback, it’s worth tipping our hats to the earliest Dexcom CGM models that came before the “G-series” — the Seven Plus and the first 3-day sensor dubbed the STS (aka Short Term Sensor).

The Seven Plus was so named for the fact that the sensor could be worn for 7 days (versus the earlier 3-day wear time). It introduced the oval-shaped receiver that many referred to as the “Dexcom egg.”

Before that, the STS was good for 3 days but it was nowhere near as accurate as today’s CGM tech. It required calibration by cable plug-in to a specific Contour brand fingerstick glucose meter. It was also not waterproof, requiring plastic coverings, and those who wore this model were often turned off by its inaccuracy, bulky size, and how the adhesive irritated the skin. We’ve come a long way, baby!

It’s amazing how the CGM universe continues to expand, with new players like the Abbott Libre flash glucose monitor Senseonics Eversense implantable CGM making a splash. To date, there are more than 40 new CGMs products hoping to make it to market someday, to compete directly with Dexcom and Medtronic in “standard” CGM technology.

Sure, Dexcom has experienced growing pains as it’s restructured and experienced order delays and customer service issues, like most companies out there. But overall, Dexcom remains one of the most exciting players in diabetes technology as it forges a path to the future of CGM.