Dexcom G6 Problem

I realize this is hardly unique: Used the G5 and it performed incredibly well. I’d get an average of 16 days from the G5. The G6 has been a very different story.

I hadn’t noticed anyone comment on the type of failures I’m having, so I wanted to see if anyone else has experienced anything like this.

My first five or six G6 sensors performed decently. I was getting 8-9 days. Nothing close to the G5, but I was consistently getting near 10 days. But then things changed, and I’m having a hard time diagnosing this.

The last six G6 have performed well for about 5 days. But then all hell breaks loose. The sensor starts constantly giving me the 3 hour Sensor Error warning repeatedly, 6-7 times a day. It tends to happen after I inject insulin (Humalog). I never inject within 3 inches of the sensor. (I usually inject on the other side.) I always place the sensor on my abdomen, follow directions to the letter.

I’ve heard people talk about using caution if they restart the sensor, as the algorithm may be much less accurate when restarting vs. new. That got me wondering if, maybe, they adjust the algorithm during the 10 days to allow for the aging of the sensor. Again, my experience has been the sensor works very well for the first 5 days, and then everything changes.

Someone on here have suggested restarting a wonky sensor, clearing the data. I will give that a try. I might move it to my arm. I’m a little concerned about that one, as I don’t have much fat on my arm. But, probably worth a try.

Dexcom has been great and replaced the failed sensors. But their advice has been very standard and I haven’t been able to get very far troubleshooting with them. I’m looking for any suggestions. I’m looking for any theories or advice. I trust you all for answers way more than Dexcom.

Trying this is a good idea, and works for me. I also use inner thighs, equally good results. Some use lower back calf, but I have not tried that.

Officially I think Dexcom support can only recommend stomach. Or they may say alternate is ok if your doctor approved it.

I use stomach for pump, and never sensor there, but could see how sensor BG level may change sooner/faster if closer to infusion set.

1 Like

Thanks for your response! I hadn’t heard inner thigh or calf as locations. The more possible locations to try, the better!

For my situation, the readings on the G6 absolutely crater when this is happening. And it happens fast, within 5-10 minutes of injection. It will drop 20-30 points for a couple of readings and then goes into error. (Comparative meter readings show no drop.)

The sensor just seems to become hyper sensitive to insulin at around 5 days. This doesn’t always happen after injection. Mostly, but not always. It’s just so odd.

Anyway, thank you again for taking the time to reply!

1 Like

This is what did the trick for me. I had been wearing it on my abdomen. Someone suggested using the back of the upper arm and I’m now on my 3rd sensor with 0 sensor errors.

1 Like

How much pressure are you placing on the injector when you place the sensor? The local Dexcom rep (not TS) suggested using very light pressure. Just barely touch the skin during insertion. Then push down against the skin to make sure th adhesive is set. That made a big difference in sensor life for me.


Thank you for the suggestion. Almost always I’ve got indentations from the sensor creased into my skin when I take it off. So, yep, I’m probably putting some pressure on during insertion.

Dexcom phone rep told me last time I called that the inserted tube is longer (and thinner) on the G6 than it was on the G5. Looking at it, that looks to be true.

I believe it is inserted a shallower angle than the G5, so I thought perhaps the two cancelled out, and the depth would be the same. But maybe not.

I will definitely try inserting with less pressure. Thank you!

1 Like

Interesting. I was told much the same thing when I spoke with a tech support person about what differences there were between the G5 and G6. He said those with low BMI will have more issues with the G6 than the G5 because of the length and angle of the filament. That sounds like what you were just told (regarding the physicality of the filament).

1 Like

Yes, interesting. I wondered about this because Dexcom tech support always asked my weight. They said the FDA mandates they ask. I didn’t have issues with G5 sensor failing, though accuracy was much worse with g5.

I tell them my weight is none of their business. Some reps move the conversation forward, others want to argue with me about my weight being a necessary piece of information. The reps that want to argue lose the argument in dramatic fashion, and end up wasting everyone’s time. Since they felt the need to waste my time, I spend an extra 10 minutes letting them know how worthless I think they are. It always amuses me when people think they’re going to win an argument with me about a stupid subject.

I don’t know how important weight is to a discussion of G6 accuracy, but from what I’ve gathered from what Dexcom has told me, BMI is the issue or least the amount of body fat in the particular area that a sensor is placed. For example, I have a little spare tire, but thin legs and arms. I use my abdomen where the G5 works great for me. Therefore, I suspect that if/when I switch to the G6, my luck will continue as long as I stick with the abdomen. But who knows–maybe a skinny arm would work too, but I’m not going to test out that theory as what I do now works well.


I’ve always used my abdomen for my sensors. I did not notice any difference between the G5 and G6 other than the G6 has a lower profile and better accuracy.

I am also looking at the if and when route and will not worry until it arrives.

I am also quite surprised because Dexcom just sent out my Medicare September subscription package and they show that order also includes a G5 transmitter so I guess no G6 for me before the end of this year at the earliest although you never know because they keep sending me transmitters for no reason I can see except to get rid of them. I have 2 unused transmitters now and with the one in transit it will make 3.

Just checked my current transmitter and it is good until end of October 2019.

I’ve never gotten more than the correct number of xmitters. They come every 3rd shipment

Mine appear every 2nd shipment for several months now and I don’t want to complain about it because am afraid of the possibility of going from too many to too few. If this keeps up, however, the oldest ones will not be able to be used as the use by date will be stale.

1 Like

that shouldn’t matter. the clock starts when u first use the transmitters. the expiration is on the box; not hardcoded into the electronics. You just won’t have warranty coverage after the expiration date, or after 90 days from first use whichever comes first.

Besides which, there’s always xdrip… :slight_smile:

1 Like

That was my philosophy too. The G5 was extremely reliable on my stomach. But for me, I’ve found the G6 on my stomach has been much less reliable. (I’m about a 24 BMI. Little bit of belly fat, but not a lot.)

I’ll give the arm a go and see if that improves things for me. YMMV.

I’ve talked to support probably 6 times in the last 3 months. They have never once asked about my weight. Strange how sometimes they insist on it, and other times it’s not a concern.

My BMI is 18.5 so not sure will find any spot that will work which is why I was relieved to hear if G6 does not work, Dexcom will continue to provide the G5 for low BMI individuals. Once they ship to us Medicare patients, we will just have to try a bunch of spots and see what works.

I just talked to them for a sensor that failed to pair. They didn’t ask weight for this issue. So maybe they only ask when the issue is Sensor Error. I don’t mind them asking if they need to, and it will help make the product better in the future. It just made me think that as @Dave44 mentioned, there was a weight connection to the Sensor Error.

Dexcom asks me about weight and/or BMI every time I call as a gauge of whether I have sufficient subcutaneous fat to support a sensor site. But it’s really ridiculous to think either or these numbers will determine if your body has a suitable site. Both numbers say nothing about how much of your weight is lower density fat vs. higher density muscle/bone, and what type of fat is present (subcutaneous or visceral) and where it distributed. My BMI and weight went up when I started working out yet the number of suitable site locations went down.

IMO the only way to gauge if an area is suitable for sensor insertion is by pinching up skin to get a sense of how much subcutaneous fat is present.