Do you go no-number to extend your G6 sensor life?

Is this a hassle when you restart your existing sensor? I just tried it for the first time and noticed in said I would have to calibrate every day. Any other things I should look out for? The current sensor seems stable, but I have had them go wonky prior to expiration, so I’m not sure what kind of life I can expect from trying to stretch one out.

Perhaps my question is moot because I am getting messages that I must replace my sensor, so trying to restart it as a no-number sensor does not appear to work. I thought I had read that people were doing that.

I use the G5 so I’m probably not on the right page here, @Jim2. I’m taking a stab in the dark here … is a no-number sensor one that isn’t giving a reading or any blips (dots) on the screen?

So just to be clear, in case anyone doesn’t know: the restart involves starting a “new” session, interrupting the warm-up after 15 minutes, then doing it over again. The first time through is intended to clear the code from the original session, otherwise the system won’t accept it, so you have to do it with no-code, but the second time the code has been cleared so it’s ok to re-enter it if you have it, and that allows you to go calibration free. I make a habit of taking a pic of the sensor’s code when I insert one so I have it handy when I do the extension re-start.

For my part I’ve found no problems with going calibration free during the extended session. Right now I’m halfway through one of those—day 15. I haven’t done a single calibration since the restart and as I’ve come to expect it seems to be just as accurate as during session 1.

As a side note, this particular sensor did go completely haywire in its initial 24 hours, I think possibly from a bad insertion, but instead of yanking it out I tried the restart thing on day 2 and it completely recovered. So this is actually the second restart I’ve done on it and it has been fine since the first one. Definitely seems worth a try before giving up on a wonky sensor.


Not sure if it’s the no-number that’s the problem. Like you say, lots of people have done it that way. The one time I had a failed restart it was because I hadn’t given the first warm-up long enough before interrupting it, and it did the same thing you’re describing. I wasn’t sure I’d had the timing right, so I did it again using the stopwatch on my phone to make sure and it was fine. It really seems to need that full 15 minutes to clear the code.

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Unlike the G5, G6 sensors have a code you have to enter that is basically there to lock the sensor to a single session. The extension process is thus all about getting the system to clear the code so it will accept the restart as a new session. Early accounts of the method assumed you had to run the extended session in calibration mode, but it turns out you can re-enter the original code in the second half of the restart process as long as you’ve noted it down somehow (they print it on the tear-away bit that covers the business end of the inserter, so you’re out of luck if you throw it away without doing that).


Thank you for clearing that up, @DrBB! I was way off in my thought process!

5 days is the most I’ve ever been able to run a G6 sensor after restart, but I know others have run them far, far longer. I could almost always get 14 days out of my G5 sensors. Either one gives me about 14 days.

I restart the sensors all the time, Since starting to do it, and ones I didn’t have to pull off because of MRi, etc I have gotten 4 to go over 26 days, with one lasting 37 days. I have been able to extend all of them and only one went 14 days.

Here are instructions from Aaron originally
You can stop it earlier if it’s more convenient.

  1. Let your sensor expire.
  2. Start a new sensor session and choose “no code”. You do not need to remove the transmitter.
  3. Let the warm-up session start and run for about 15 minutes. I set a timer on my phone.
  4. After 15 minutes, STOP sensor. It may warn that you cannot start a stopped sensor, but this is not true.
  5. Start another new sensor and enter your existing sensors code. (or no code if you don’t have it)
  6. The sensor will warm-up for two hours and start giving readings after

The last one I did had a couple restarts on it.
And like I have said, I just let xdrip do it. I don’t even think about it anymore. It’s that easy!

To a degree.
I don’t understand why the restart works but we certainly have done it a number of times.

However, it is also possible to use two different physical sensors with traditional and documented session start procedures where each sensor has the identical code.

BTW - When we do extend the G6, we check often with a meter (Contour Next One) and are not shy about adding calibrations.

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Something to think about, I never enter a code into xdrip. And it can restart the sensor without issues.
This leads to believe there is another way to do this?
Or maybe xdrip is using the last known code, and keeps using that one until a new one is entered?

In that case, I think physical removing of transmitter clears code, and you reenter after adding transmitter to new sensor.

In the Extend sensor document, removing transmitter (using BG strip), then insert to same sensor is recognized as new sensor, so likely the code was cleared.

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I think I understand now why it didn’t work for me. I wasn’t doing the 15-minute thing. I also had not saved my code. If I am understanding this correctly, you can restart without the code, but you will have to calibrate, or you can restart with the code and you won’t be asked to calibrate. Both methods using the 15-minute trick.

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That’s exactly right.


I tried to restart a sensor last night using the 15-minute method and the current code, but I still got the message that sensors can be used only once. It was late, and I didn’t want to get warnings all night, so I just removed it. This was a sensor that I had just put on to replace one that was giving trouble. I think I screwed up by putting the transmitter in the new sensor before stopping the session and starting a new one, so after awhile I got the notification to replace because sensors can be used only once. At that point, I started a new session with no number, and after 15 minutes, I stopped that session and started a new session with the sensor number, but that failed.

The Dexcom G4, G5, and G6 each represent advances in algorithm technology, with the G6 also benefiting from improvements in the sensor itself.

While the algorithms may differ, what each of the transmitters have in common are correction curves that tweak the raw signal differently over the initial 24-48 hrs vs the remainder of the 7 or 10 day approved usage. Hence the wonky readings for the first +/- 24 hours (especially G4s and G5s which used an inaccurate 72-person “best fit” correction curve that’s proven to be out of range for many people.)

No surprise here either: Dexcom seriously frowns on users extending G6’s beyond 10 days. And they continue to look at all ways users are bypassing their protocols, and taking measure to eliminate code loopholes in updated product versions.

The Dexcom G6 CGM algorithm is designed for optimal performance for up to 10 days of sensor wear. Intentionally altering, modifying or hacking the G6 system to extend the sensor usage beyond the labeled 10-day wear period may compromise the system. This can lead to inaccurate CGM readings, resulting in missed hypoglycemia or hyperglycemia.

The Dexcom G6 CGM System was granted De Novo clearance in March 2018 by the US FDA as the first of its kind interoperable CGM (iCGM) System. The FDA also published several special clinical performance metrics for an iCGM. One of these special controls requires manufacturers to demonstrate that The device must include appropriate measures to ensure that disposable sensors cannot be used beyond its claimed sensor wear period. Dexcom is obligated to take measures at all times to prevent sensors from restarting and as such must continually evaluate design mitigations to ensure adherence to this special control.

A link to the entire paper is HERE (published Feb 2019)

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Thing is, Dexcom already wanted to make the G6 a 14 day period, but cannot get adhesives to work that long.

Just in case it helps next time, I find I start mine on my reader the most, but I have to turn off my phone until it’s past the 2 hours warm up period and then the phone picks it up as a new sensor. Otherwise the phone reads it as an old sensor and will stop the process.

If I go past say 25 minutes wait period, I have to start the process over again.

I don’t know what happened wrong a couple times, I believe it was between my phone or the wait period too long, but you can try restarting it several times and it doesn’t seem to matter. It seems to eventually work if done right.

The definitive solution to my adhesion issue on the Dexcom G6 was to use SkinTAC adhesive barrier wipes… Rub it all over the area that the sensor is going to be applied on top of, apply the sensor quickly (before the SkinTAC becomes too “tacky”), and then use SkinTAC remover pads to clean up the sticky mess.

I apply my G6 sensor to my belly area with SkinTAC… and do not use ANY over-bandages or adhesive patches, and the G6 sensor sticks on for 20 days perfectly with no loosening of the original patch…

If you’re willing to put up with the mess, SkinTAC is THE solution to sensor adhesion problems…

Link for the adhesive wipes:

Link for the cleanup pads: