We’re excited to have been using the new Dexcom G6 continuous glucose monitor (CGM) over the past few weeks.

The new G6 model got FDA approval on March 27 (see our coverage here) and is expected to hit the market very soon, in early June 2018. The most notable changes brought by this latest generation of CGM tech are that it’s officially approved for 10-day wear (rather than 7 days with prior generations) and that it no longer requires fingerstick calibrations to confirm accuracy.

We’ve heard that about 1,000 people were included in the initial pre-launch group who received early units, like us. After wearing the G6 for a few weeks, we are ready to share our first impressions from our personal POVs…

Naturally, being the impatient patient I am, I ripped right into the G6 boxes as soon as they arrived and began the switchover process within minutes. Which is to say, I didn’t read a single word of instructions before I downloaded and started up the new app and slapped the new inserter on my body. In my defense, this rash approach makes for a great test of just how intuitive a product is, or not.

That Inserter Bot

While certainly spacy-looking, the new “inserter bot” (as I call it) is a nice improvement in insertion comfort. After peeling off two separate top-and-bottom adhesive backings, you just press the handle-shaped “bot” to your belly, pull off a tiny bit of protective plastic, and push the big orange button. I almost did not wince at all. There’s a lot of “bot” left to throw in the garbage though, and given that it’s no longer clear plastic, it just feels very environmentally unfriendly.

But wait! One of the main differences with the G6 is that there’s a code for each new sensor printed on the top adhesive, so don’t go throwing anything away before entering the code into your receiver or app.

The app does give you an option to start a new sensor with “No Code,” but a warning pops up that it will not work as well and could be inaccurate. And without the code, you cannot take advantage of the fact that G6 is factory calibrated, so you’ll have to start with dual fingerstick calibrations like the old system.

The startup time is supposedly still two hours, but I could swear it went faster than that on the three sensors I’ve used so far.

The sensor itself is a teensy bit flatter than G5, but pretty much takes up the same real estate on your body – so not a huge change, IMHO.

Soft Look, Small Print

The new app has VERY muted colors and small, understated font compared to the G5 app, making it look kind of washed-out and (to my mind) less engaging.

And dang — this new app has a lot more text that pops up here and there, making the interface appear more complex. By that I mean:

Any time you click the calibrate icon, it takes you to separate screen with a three-part warning, plus a “learn more” link that explains what calibrating does. This is clearly a result of FDA-mandated cautionary steps now that the Dexcom is cleared for making dosing decisions (hey, be careful to wash & dry your hands for an accurate reading!) but I found it somewhat annoying.

There are also permanent links at the bottom of the screen to “Events” and “Settings” that take you to screens that are just… well, more text-y and fussier than the layout in the G5 app.

The Alerts options, found under Settings, are much the same as before, except for the addition of the much-heralded new Predictive Low Alert – that’s supposed to let you know when an urgent Low is on its way. I really wanted to test that, but was unfortunately (or happily?) unable, even when I was in the low-hundreds with a straight-down arrow sitting on a spin bike. Turns out it will only alarm if you’re falling VERY FAST and heading for 55 mg/dL within less than 20 minutes. Maybe I should’ve held off on the Skittles just a little bit longer.

Note that the “stop sensor” command is kind of hidden at the very bottom of the Settings screen, so it may take some searching when in need of an abort-mission on a sensor that’s popped off.

Adhesive Challenges

Speaking of sensors that pop off… this may be just me, but my first two sensors just refused to stay stuck. The first lasted only 5 days, and the second one fell off on day 9. I am using the same Skin Tac adhesive as before, so… ?

The company tells us the adhesive hasn’t changed from their “pressure-sensitive acrylic adhesive coated on top of a polyester spunlace fabric.” But I am struggling. Anyone else?

In that sense, the fact that you can no longer re-start a sensor to extend wear time beyond what’s FDA approved is a complete non-issue for me personally. My G5 sensors regularly plopped off on day 10 anyway, and I always found the accuracy starting to decline on my last few days.


Speaking of accuracy: so far I’ve found the new system to be astoundingly good. I’ve only once seen a 30-point difference between the CGM and my OmniPod meter. I’ve also had far few “lost connections” which was an ongoing problem with the G5 app even when I had my phone on my bedside three feet from my belly at night.

Overall, I would say switching from the G5 to G6 is not a huge life-changer in terms of form factor. But the need for fewer fingerstick calibrations and improved reliability sure are NICE.

I guess what I’m saying is: Yes, you’ll want to upgrade, but if you have to wait a bit, be patient. If you’re already using and liking the G5, then G6 is not going to blow your mind or anything.

So, the G6 arrived on my doorstep the day before my vacation began at the end of April. Rather than putting the CGM on and turning my time-off into a G6-chronicling experience, I held off on connecting it for a week until returning home.

Much like Amy, I didn’t read the instructions because I’ve been a longtime Dex CGM’er and I thought, “C’mon, I already know what I’m doing!” Yep, as expected: I found the G6 pretty self-explanatory from the start and didn’t really need any guidance on getting it connected.

At first, I wore both the G5 and G6 at the same time to compare them side-by-side even though Dexcom later told me you’re not supposed to do that, because apparently the Bluetooth signals can get crossed and interfere with each other. (I have not experienced that issue to date, with my first two sensors).

Honestly, as a previous G5 CGM’er and a longtime G4 user before that, this latest CGM tech didn’t WOW me or knock my socks off. But I do like it and think it’s a great new piece of CGM tech. Here are my first impressions, in list form:

Not Universally Smartphone Friendly: First off, it’s awesome that Dexcom tells us the G6 is compatible with both iPhone and Android smartphones right out of the gate. Unfortunately, it’s not compatible with every type of Droid phone, and my luck: the two Android phones I own are not on the list so don’t work with the new G6 mobile app. Therefore, I was forced to use the new G6 touchscreen receiver for now.

Touchscreen Receiver: Unlike Dexcom’s previous receiver that resembles an iPod, this new receiver has a vertical orientation and is a bit bulker and larger in size. It also doesn’t have a sleek belt-clip like the other receiver, so I had to carry it around in my pocket rather than just attaching it to my waistline as I prefer. We have to assume that Dexcom assumes most of its users are moving to the mobile version, so there’s no longer a big call for belt clips. But if you are using the receiver, you still need an easy way to carry or wear it. So yeah, I MacGyvered my own…

I had a lot of fun snapping the clip off the back of an old Medtronic holster clip, filing it down flat, and super-glueing it onto the back of the black Dexcom skin case that came with my CGM. This worked out well, allowing me to clip it to my belt-line while also being able to take off the skin case and just slip the receiver into my pocket.

Accuracy: The G6 has been pretty darn accurate for me as well, usually within 10-25 points from my fingerstick meter at the most. Overall, the G5 has often run on the lower side while the G6 has been on the higher side compared to my meter readings, so they pretty much balance out. I noticed the G5 has often been more “dramatic,” in showing spikes or plummeting numbers, whereas the G6 appears to show changes in a more measured way, so far. Personally, I have no problem using my G5 or G6 fordosing insulin or treatment decisions as the FDA has deemed OK to do.

Fingersticks: Even though you’re not required to enter daily fingerstick calibrations as you must with the G5, I voluntarily chose to enter calibrations for the first sensor to check the accuracy. The Dexcom didn’t prompt me for any calibrations during my first seven days of the initial sensor. But on Day 8, after entering a calibration, the G6 soon told me that it needed a fingerstick calibration! That was the first and only time this happened, and in calling Dexcom Tech Supoort, I was told I was the only person who’d reported this issue so far after entering a sensor code. (If you start up with “No Code,” the system will prompt you for fingerstick calibrations periodically.)

Personalized Settings: It’s also very cool that Dexcom has weaved customizable alert settings into the G6, meaning you can program your High and Low alarms differently based on time of day or night. Unfortunately, this is only possible with the G6 mobile app and not an option on the receiver. So I wasn’t able to enjoy this new feature. It also annoyed me that the touchscreen receiver did away with the CGM graph descriptions for 1, 3, 6, 12, and 24 hours; instead, you have to tap the touchscreen to see the various timeframes “manually” and it can be tricky to isolate the intervals you’re looking for.

Predictive Low Alert: Fortunately, the new Predictive Alert notifying users when they’re going to cross the Urgent Glucose threshold of 55 mg/dL in the next 20 minutes functions on both the mobile app and receiver. I appreciated being able to know I’d be crashing into dangerous Low levels before long, and a fingerstick and my G5 confirmed this was in fact accurate, giving me more time to treat in advance of actually going that Low.

10-day Wear (No Restarts!): This may be the most bittersweet of all — the fact that the water-resistant G6 has a hard shutoff at 10 days, compared to the previous generations labeled for 7-day wear but could be extended for days or even weeks beyond that by restarting the sensor. That’s not easily doable with the G6, despite a few scattered reports otherwise. Dexcom has actually designed the new thinner transmitter to be snapped into the sensor differently than prior generations. The little tabs that held the G5 transmitter in place within the sensor bed are gone, so this new G6 transmitter can’t easily be removed from the sensor bed without taking it off your skin first. The sensor bed actually bends downward in order to remove the transmitter, making it pretty near impossible to take off the transmitter and re-attach it.

This inability to restart is a big deal for many out there. I tried to restart my first and second sensor unsuccessfully — both leaving the transmitter on and also trying (unsuccessfully) to take it off the sensor bed while it was still stuck to me. At the 10-day point, when the sensor shut down, I told it to restart without entering a new sensor code (agreeing that calibrations would then be needed, like with the G5). But despite a short glimmer of hope, when the G6 started the two-hour warmup, it declined the restart about 30 minutes later and demanded a new sensor. ImI sure DIY’ers will keep trying to fkfigu out ways to back the G6 by removing the transmitter, in restsrt attempts…TBD what happens there.

New Disposable Auto Inserter: The new plastic auto inserters come three in a box, individually packaged in plastic casing as opposed to the little “sack” that G5 sensors came in. These spring-loaded applicators are self-contained so you never see the needle or even the sensor itself, and all you have to do is to press the orange button to inject a new sensor. This made it so much easier to insert a new sensor by myself, single-handed. I personally never shuddered at the thought of the other G4/G5 sensors that some describe as a “harpoon,” as they only rarely hurt. To each their own, and Your Diabetes May Vary. I found the new sensors didn’t hurt any more or less than the old ones. 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.

Not #WeAreNotWaiting Friendly (Yet): OK, this one is written with all kinds of privilege from someone who’s had the luxury of data-sharing through the CGM in the Cloud hacking community. As a Nightscout-xDrip user since late 2014, I’ve enjoyed the ability to access “raw data” (glucose readings that aren’t filtered by the Dexcom algorithms) along with other non-Dexcom features on my Android mobile apps. I’ve been able to share that data with my wife no matter where we’re at. Not the case yet with G6, since it’s not even officially launched yet. But surely, it’s only a matter of time before the hackers start finding ways to liberate the G6 data so it can better fit our individual needs…

In summary, based on my own first impressions, I’m not going to actually upgrade to the G6 anytime soon. Word is Dexcom plans to start upgrading existing customers later in the summer after the official launch, once they go through current G5 supplies. But I’ll hold off as long as possible, mainly since my particular Android phones aren’t yet compatible so I can’t yet take advantage of all the new features.

On Upgrades, and Medicare Coverage for G6

Dexcom has published its initial upgrade plan, but nothing’s final until after the launch begins.

If you’re an existing Dexcom user who’s not anxious to upgrade for any reason, no worries — you won’t be forced to do so. Although Dexcom will likely try to convince you to switch to this latest and greatest tech.

Company execs tell us they’ll continue making the earlier generation G4/G5 transmitters and sensors for the foreseeable future, if only because some still use integrated insulin pumps and need them.

Meanwhile, Medicare coverage is already in the works. The Centers for Medicare and Medicare Services (CMS) initially approved the G5 model for Medicare coverage in early 2017, and we’re told Dexcom has filed for Medicare coverage on the G6 with a hopeful decision on that by year’s end. Of course, Medicare coverage for CGM use with a smartphone app remains a work in progress. Dexcom’s been pushing for that policy change with CMS for more than a year now, and Congress members have even sent letters to CMS demanding a fix to this key issue, we’re told. Dexcom CEO Kevin Sayer hopes it will be resolved this summer, but that’s TBD based on Medicare policy-makers of course.

We also urge Dexcom to continue working with private payers to make its CGM technology more affordable and accessible to the broad D-Community, of course.

So that’s that our scoop on our first impressions. We’ll share more about our experiences later on down the road.