Advice for sleeping with defective sensors

I need some advice please. Some ideas for what to do at night when I know the sensor is failing to detect any BG at all, so it’s constantly giving me false low alarms, beeping and waking up my wife, keeping me from getting anything close to a decent sleep.

Should I just turn off Control IQ? That wouldn’t stop the sensor from working incorrectly and giving me false alarms would it?

Obviously, stopping the sensor means I’d need to insert a completely new one the next morning.

I just started a new one at six this evening, because the last one crapped out before its ten-day cycle ended. It just completely stopped detecting any BG at all. Four times yesterday alone! Each time, I calibrated it from a finger stick. It restarted, most of the time, and less than an hour later, the readings plummeted from 200+ to less than 80 in only three successive measurements! Each finger stick reported BG >200, while the sensor said <80!

Now, by 10:00 pm the night I started a new one, four hours after starting it, the new one is crapping out the same way!

I’ll go online tomorrow and report it and I’ll get a new one, but this kind of sensor failure or some other failure is happening to me in almost half of my current three month batch!

Are any of you also experiencing what appears to you to be a frequent deterioration of overall product quality? Not just one off problems here and there, but almost half the time in a 90 day batch something goes wrong? That’s what’s happening to me, IMO. I really think Dexcom has lost its ability to make top quality sensors.

And the most frustrating infuriating about it is that I just don’t trust my health, my life, to Dexcom sensors any longer and I simply don’t know what to do except go back to finger sticks, which for me is 6-8 a day on the average, given my fluctuating sugars.

Sorry for venting, but I just can’t cope any longer with the lousy product quality I think I’m getting on a regular basis and I need to find someone who cares and who can give me some suggestions for what to do.



I have noticed nothing abnormal in terms of Dexcom reliability. My current and last couple of sensors are from lots 5311113 and 7302424.

Is there any chance that you are dehydrated for some reason? I spend part of the year in NM where the humidity is typically very low. I have learned that if I do not increase my water intake when I go there that I begin to see more erratic sensor behavior. Of course, there are medical things that can cause dehydration, but simply failing to drink enough water can be problematic.

Best of luck,


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To avoid fake lows on a brand new sensor (they are quite common in the first hours for me) I do a 12 or so hour presoak on a new sensor before I attach the transmitter. For me it is a world of difference.

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I’ve noticed in my last 2 sensors that they crap out on the 10th day and give erratic readings and then nothing.
It’s irritating.

I would not go to bed with a bad sensor. I would change it and let it warm up while I’m sleeping, knowing it will only be 2 hours of no protection. Sure it might not be perfect at the start but it’s better than nothing.


I’ve done the presoak to improve the sensor reliability for the startup day. A 24 hour presoak seems to work well…but I have noticed that most sensors only last 8-9 days for me. When they fail unexpectedly I lose the opportunity to do a presoak, so lately I have been biting the bullet by inserting the new sensor at the first sign of erratic readings or dropout sensor errors and starting 24 hours later. I’ve probably ended a few sensor sessions prematurely that way but the improved reliability from presoaking seems worth it.

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I find that recent sensors are much more sensitive as to placement. Be sure and place your pump ON THE SAME SIDE OF YOUR BODY as the sensor. If not, I find that it does exactly what yours is doing… waking me up with all kinds of alerts, especially the Out of Range alert. That means that if your sensor is in your right arm, the pump should be on your right side. Same on the left. Another thing that I believe not many pay attention to is to clean the transmitter with alcohol before inserting it into a new sensor. I do both religiously and have not had any problems since.


I don’t have a solution, wish I did. I cannot put Dexcom sensors on my abdomin. There they go completely wonky by day 7. The sudden drops in 15 minutes to a false low. Sometimes that false low is followed by a loss of data for 20 to 40 minutes. When It happens at night I get a really loud alert that will wake me out of the deepest sleep,

I still get some of this when the sensors are on my arms, but not as severe. It happened yesterday on day 10 with both false lows and highs and a data breach.

This sensor behavior has been pretty constant since I first started using Dexcom G6 2 years ago. Early on I made the mistake of trusting the data and over treated a hypo that wasn’t a hypo. I don’t do as many finger sticks as I use to 8 to 12 in a day, but if I have any doubt I will test.

There are some people who don’t have these issues, and some not only have these issues but are able to restart sensors for use up to 30 days. Then there are others like me with wonky readings and disconnects around day 7.

There are a lot of factors in the way these sensors work, biological, chemical, electrical and environmental. I get that. But with lots of people reporting trouble at day 7,8 and up to 10 it would be nice to get an answer.

G7 is touted for extended use. What if it still has the 7 day issues?

I know I am ranting,


I’ve had bad sensor batches. That was really bad when I was using automatic pancreases system. I shut down the system automation. You gotta collect data and send those things back to Dex because if you don’t tell them about failures, then they won’t even know.

I’m not currently wearing my Dex, but that’s problems I have with the adhesive and them just falling off a lot. I have complaints about dexcom over the last year or two, but there is no alternative and my Doc told me to just get over it. I think she was correctly assessing the situation.

I know one guy who wears both a Medtronic and a libre sensor in an effort to overcome the inaccuracies of each.

I wonder if you got a bad batch of sensors (possible manufacturing failure, or maybe they were subject to extreme temps in transit).

Your not over calibrating, right? Have you tried starting them up, “No code?” Your not taking a bunch of ibuprofen?

Luis, don’t apologize for ranting! Misery loves company! I’m sorry you have the same pblms I have but it is very enlightening to learn that you, at least, understand EXACTLY what I’m venting about because PRECISELY the same thing is happening to you too. I hope we both find a good definition of the cause so we can find a good solution!


People something is up with the G6 that we are not being told about. All of the listed complaints have started to happen just after the release of the G7.
I started with the G4 and have progressed up to now. Only in the past 6 months have I started to have issues. I have NEVER had a sensor fail. I’ve had two fail on day nine. I’m now seeing me run a normal level for several hours say 140 then drop to below 50 in 10 minutes. A pinger stick show 140 so I recalibrate . Usually won’t happen for the rest of the day. Other Constant issue is signal loss. We all know BlueTooth is a fickle mistress. I use my phone and Dexcom Receiver both. Again in the last 6 months I’ve noted I can’t leave the room without one or both loosing signal. I live in a small apartment and was able to go room to room with out issue. I wear my sensor on my stomach (like a good boy) I use to have no issues at night as the phone and receiver were on the night stand 1.5 feet away. Now if I roll on one side of the other , it’s signal loss tile.
As stated all of this has started sense the release of the G7.
And the Big question , why was it not released I, the U.S. 1st.

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Here is the link to the Dexcom page about pain medications interfering with G6…Acetaminophan is a problem but they do not list ibuprofen. Does ibuprofen use cause a problem with Dexcom G6?

Interfering Substances and Risks | Dexcom

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Because they withdraw it from FDA consideration. They ran into a problem with the FDA review team. I suspect it had something to do with cyber security, but that was never officially stated, that’s me interpreting between the lines. Regardless, Dexcom expected to be denied their pre-market approval because of said problem, and withdrew their filing until they could address said issue, and will resubmit an “improved” version that will guarantee approval.

It’s not uncommon with medical devices. There’s a lot of discussion during the review process. It’s pretty easy to spot the red flags along the way. Better to withdraw the application and address the issue(s) preventively than to flat out be denied premarket approval.

I don’t know if it’s been resubmitted yet. But when the G7 is finally approved in the US, they are under contract with Tandem (and I assume similarly with Insulet) to continue to manufacture and support the G6 for 3 years after the G7 becomes available in all their pump markets. It’s a guarantee that their patient base won’t be left in the lurch without access to sensors. So it doesn’t make sense to intentionally tank a product line that they’re obligated to make and replace.

I really believe it just comes down to bad quality control, staffing issues, supply shortages, etc… The same problems all businesses are trying to recover from right now. It is possible that they’re scrimping on the glucose oxidase reagent or using lesser quality materials because of those cost/supply issues. My most recent box of sensors was manufactured in December 2021, still deep in the pandemic.

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Are you ever getting reliable data from those sensors? I don’t quite understand why you’re adverse to stopping it if you’re getting such bad, untrustworthy data? Or is it only doing this at night? If it’s only happening at night, I’m wondering about common Dexcom issues, like compression lows or false readings because of dehydration. (Not drinking in the evenings to avoid trips to the bathroom?) Or maybe a nighttime medication that interferes.

You want to turn off Control-IQ anyway if you don’t trust your sensor data. You certainly don’t want it stopping your basal for extended periods of time over a false low, or worse, dosing insulin for a false high. That will only stop about half of the alarms, though. You would also have to go into your settings and turn off the high and low limit alerts, which unfortunately also removes the high and low visualization lines from your graph. Unfortunately, you can’t do anything at all about the critical low (≤ 55) alert. That one is going to wake the dead, unless you bury the pump under your mattress.

Are you aware there are volume options under settings, too? You can turn all the alerts to vibrate only, which hopefully won’t wake your wife. I know I can sleep through the vibrations myself so long as the pump isn’t actually touching me.

I don’t know whether I previously shared my August blogpost about the mental stress of Day 1 Dexcom sensors. I have always had bad Day 1’s but somehow it seems worse recently or I am just more impatient.

I always turn off Control IQ when I am having sensor problems. Since my sensors almost always start “Low” or in the 40’s, I can’t have Control IQ suspending my insulin for hours at a time.

I often turn off my phone overnight for the first night of a sensor. My newest trick is going to try putting the pump in a Faraday bag overnight to stop communication with the transmitter. I’ll have the Out of Range alert turned off. So I’ll have no Dexcom numbers but that is better than constant alarms for false lows. When I talk about doing these things you’d think presoaking the sensor would have the same effect but it doesn’t for me.

A constant battle and I try to remember the days before any blood glucose monitoring….


Thanks for the come back

I definitely recommend “no code” mode. Accuracy is much better for me and I generally get a full 10 days out of the sensor. I also “presoak” for 5-6 hours whenever poss.

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I always go with no code. I used to have lots of trouble with my G6 sensors, but now with no code, soaking for 12 hrs, and wearing the sensor on the front of my arm, where I have very little fat, my sensors work correctly, after the warm up, for the next 10 days. I have only had one sensor that gave me problems recently and I waited and it straightened itself out.

Funny that several report false lows after warmup the 1st day. It’s the opposite for me. As to No Code, doesn’t that require calibration by finger stick once or twice daily?

I tried presosk but it didn’t make any difference about the 7 day problem.

I am more irritated about this than in the past. I buy my test strips out of pocket. They have gone up slightly more than 50% in 3 months.

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If you use “No Code” then are you required to calibrate twice a day for the life of the sensor? I’ve never used No Code.

For me although my Day 1 is horrible, all of my sensors last 10 days with mostly good accuracy.

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I get that. My 1st day numbers are high, yours are low. You get 10days minus the 1st perfect, while I have trouble regularly starting at day 7. And then there’s those who can restart sensors.

It’s the inconsistency across the community of users that baffles me. I spent most of my life measuring metrics, diagnosing and repairing faults in complex electronic systems.

The only thing I can think of is a possible immune response or a biochemical effect of some people that degrades the sensor reagent.