Dexcom G7 - Failed Sensors

I’m on a trip right now to HI for family matters, though we’re taking advantage of some of the time to see some sights. I use a small backpack for all my D supplies (just got a new one with the Trio logo and “#WeAreNotWaiting”: CGMs (three for a 10-day trip, supposedly good for 10-days each); 5 Dash pods plus the one I had on (should need two of them); three pens of Novolog plus the one already in my kit (should need one plus the one I had in use); plus the roll of flexi-fix I use under my pod to stabilize the cannula; plus alcohol wipes, plus extra needles (always have baggy of them). **Of note:**the hotel refrigerator nearly froze two pens worth of Novolog! Yes, I have a Frio bag for them, but have never had an issue and checked to the “feel” of the frig; regardless, the Frio bag was frozen solid, but the pens appeared ok. Tested the Novo with one of my “spare” pods (time for a change any way and the Novolog still works…was dreading the call back to my Endo for a script to the local Costco!. Lesson learned: Unless required use the Frio pouch without the frig!! (I’m an old dog…but I can learn!) And yes, I do use some of the space for chargers, cables, and my iPad!

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This is the season for traveling - and the more complicated our systems get, the more complicated the backup required. We’ve had a bunch of past threads on what to pack and travel stories, and I think I’ve written this one before but I can’t resist … which results in the following advice:

Don’t rely on foreign post offices for any of your supplies

I was on a long bike trip in Europe and thought I would mail my Dexcom / Tandem supplies to myself at places I was staying at in Denmark and in Italy. I mailed the packages about a month before I left the US. Neither of my packages made it in time. So I ran out of Dexcom / Tandem supplies, and ended up using my backup, which were insulin pens I had brought along for the last couple of weeks of the trip.
Interestingly, the packages of supplies that I sent to myself made it back home to the US - and showed up 3 or 4 months after I had gotten home.

I know this is a bit of a hijack of this thread. Sorry.

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How about HAL in 2001?

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Forgot to include I take the pdm’s for both the G7’s and the Dash pods as a backup to using Trio and the Dexcom apps on my phone. I also have the Trio and Loop apps on my wife’s phone! Think I’m covered…until…

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HAL is a script writer attempting to suggest AI. 2001 was released in 1968, when I was 8. ATM we have got there; we have finally managed to develop computers that can do what HAL suggested and way more.

Did HAL get upset, or was that your monkey brain kicking in and saying HAL was?

DarkStar is my goto. I can’t surf, but at the end I wish I could. (I ski instead - almost as dangerous, hey, weight; give me a planet with an atmosphere and a pair of skis!)

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Yeah. Much as I hate Lantus and the marketing behind it I known I can live 25 days with one 3ml pen of Lantus. Forget Jeff Wheeler. Just give me that Lantus pen and, oops, a needle to screw into it (just one of course.)

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A little late to the thread here but so far I’ve had only one G7 sensor make it the full 10 days out of the last 5. I’ll be switching to Libre as soon as practical. I should note that I’ve never had a problem with getting a replacement using the online form. Today I had one cr** out at 4 days followed by one during the warmup time. I phoned those two in and had a prompt response of two more replacements.

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Totally get your frustration, two failed sensors in a day is rough. G7 can be more sensitive than G6. To help avoid issues: make sure the area is smooth and clean, let it dry fully before applying, choose a low-pressure spot, and use a patch (I use NJAP) to keep it secure. You’re definitely not alone in this.

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When I finished off the G7s made in 2024 my next two sensors have been normal. Tried Libre but phone battery suffered from the app, no calibration and no control over alarm, so not for me. I got one that registered 20 points or more low and kept alarming when not necessary. Hope Dexcom can recover their quality control and stop selling marginal product.

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Thanks for the heads up @ErinRods and welcome to FuD ! Your input on any and all topics will surely be appreciated, stick around if you have time to check in and comment occasionally.
That second failure had the dreaded recoiled/kicked back wire…here’s a picture after I removed. That one hit my attitude pretty hard…I was on a 3 day trip to the east coast and had just started my only spare sensor. That sensor failure during startup put me back on fingersticks for the next 48 hours.


Anyway, after getting home and thinking a little more deeply and reading the pros/cons of Dexcom vs Libre in this excellent thread with multiple user experiences I decided to stick with the G7 for the time being (and carry more spares when I travel).

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The Dexcom president/COO did an interview addressing some of these issues (sensor not connecting and bent wire/“goosenecking”), which essentially boil down to they are aware of them, they’ve adjusted manufacturing processes to address them, they supposedly do not tie directly to any particular lots to be able to track them.

In the last month I’ve had 2 sensors with the goosenecking issue and another sensor fail after a day for unknown reasons so I, too, am a bit irritated with Dexcom G7s at present

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Actually he only said this about the sensors that won’t connect/pair. He seemed to imply that the goosenecking problem was becoming more prevalent earlier this year and then was addressed. I had the impression maybe there are specific lots with the goosenecking problem although he was a little vague about that.

Thanks for that link by the way. Very informative interview.

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Are other people submitting for replacements if they fail on day 8 or 9?

Heck yeah. Those are the worst, seems like it always causes a mental kerfuffle when they unexpectedly fail near the end of a 10 day session. I like to plan ahead for the new sensor (trying to avoid vigorous BG lowering activity during the initial 12 hour wonky time) and a failure on Day 8,9 or 10 throws the plan out of whack.

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@John58 About a month ago I had one die (communications failure, then no contact for an hour+). I use the Dexcom iPhone app, & take the PDM on trips as a back up. It died Day 10 about half way thru (not counting 12-hour grace period). I was on an Alaska cruise, had no internet at the time, and was busy enjoying sights and family, so didn’t send the replacement form. It used to happen just often enough to make me question Dexcom’s reliability; but this was the first time in 9-10 months for a complete failure, though I’ve had the dreaded “Wait 30 minutes.” Shouldn’t matter a lot, particularly when Dexcom’s set to release its 15-day sensor any day! (Speaking of it, does anybody “know” if it’s the same sensor with different packaging? Dexcom’s site only lists a slightly lower MARD, wear time, and age requirement, no other differences, and only 73.9% make it to 15 days! Nice but not enthralling!)

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When I travel, it’s typically 7-14 days at a time, with a country change every day (no way to get supplies or have them sent). So, with the G7, I carry two sensors, which is all the room I can afford in my gear; it’s likely on most trips that a sensor replacement will be required. Frequently both sensors fail, leaving me without a sensor.

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No, not at all nice. If it turns out to be that bad for me, I may find it unacceptable.

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Yeah, as I’ve said somewhere in these threads, that is a crazily poor success rate for a product like this. One out of every four will fail! That’s unacceptable especially because getting only 2 a month means that a failure can easily leave you without a sensor for several days if you aren’t careful about when you reorder them.

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My history with Dexcom G6 and 7 goes back about 6 years. G6 would often have issues around 7 days where the BG level would take a sudden drop and then I’d get a message to wait 3 hours before changing the sensor. It might come up in 20-40 minutes, if not it was usually toast.

This problem wasn’t just mine but others reported the same thing, while still others are able to restart the sensor 2-3 times. This tells me that it has something to do with body chemistry or maybe even an immune system reaction.

G7 has been really stable for me. The only issues I’ve had were mechanical. In the time I’ve been on G7 2 fell off. The other failures were out of box failures due to the sensor lead not getting inserted. These are the ones with the loop of sensor lead sticking out of the hole.

The adhesive on the G7 must be Gorilla Glue :rofl: I have applyingt Goo Gone Bandage and Adhesive Remover to the pad 5 minutes before removal helps to prevent damaging my old (75) skin.

I usually get 10.5 days out of a sensor and have little problems with the G7.

As I wrote in the begining about my and others 7-8 day issue with the G6 while many don’t experience the same problem, there may be some who have problems with G7 that don’t affect me.

We are dealing with a product that uses a chemical reaction with bodily fluids to generate an electrical signal which is then sent via bluetooth to another device. It is amazing to me that they work at all much less as well as they do.

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On another forum I bemoaned the residue from the sensors that seemed impossible to remove, leaving black rings and collecting crud for days, defying alcohol and other efforts to remove. Certainly acetone and other things might be used, but on the soft skin areas (inside or back of arm, etc), there’s a high absorption rate, and those are irritants, too.

Someone suggested uni-solver wipes. I ordered some off Amazon, and one wipe does the trick beautifully. I carry a few in my bag when traveling.

When I was looking for a film barrier wipe to try under the sensor, I ended up going with one from the same maker of the unisolve wipe; Smith & Nephew. Skin-prep, I believe they’re called. Two sides of the same coin, I guess; one removes bandage residue and adhesive (unisolv), and the other preps for the bandage or sensor and puts a slight barrier between the adhesive and skin (skin-prep). It claims to improve adhesion, while also making the bandage (or sensor, in this case) easier to remove and clean up. We’ll see when it’s time to come off.

With the exception of the recent sensor that fell off due to lack of adhesion, the others have held on so well I thought they’d tear skin coming off.

I also just received, but haven’t tried yet, some underlayment patches from Glucomart (on Amazon).

They’re shaped like the G7 sensor, have the hole already cut, and I should be able to line it up based on the flat surface at the front of the G7 applicator, according to the directions. No idea if it will need an overpatch. Other than rolling over at night, the most adventurous thing I do in a given day is get in or out of the shower (a towel seems to be a threat to the sensor, catching on the sensor while drying off). I was surprised the last sensor fell off, because everything else sticks like its permanent, and given that a blow torch wouldn’t remove that adhesive, the shower ought not be any threat.

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The amazing thing to me is that while these problems are well known in the diabetics communities there has been no FDA or public notice on anyone’s part about these prevalent problems.

According to my endo, this was Dexcom’s choice. They didn’t want to do a recall and rather wanted to handle these issues on a case-by-case basis. And they had that legal option, so they took it.

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