Restarting Sensors

Hi Everyone,

New guy question here. I’m on my first ever sensor, and I keep hearing about everyone restarting after the 7 days and keeping the same sensor to save supplies and get better/more accurate readings. Could someone please run down a little checklist of how to restart with the best results and not lose data? Do I need to stop the session early, or leave it run until the end? Do I actually take the transmitter out and then put it back in? Etc.

Thanks so much for your help. I’m so super pumped that I’m finally getting to see the CGMS data!



Hi Brett.
I have been using my CGM for about 3-4 months now and love it.
For my first few sensors I replaced them at day 7, as I became more comfortable with the idea of extending their life, I have begun to do so.
I have seen posts with methods of not loosing data, I find it easier to forgo this 2 hours of readings.
Here is what I do, this works for me, your results may vary:
Day 7 as the sensor counts down, it will stop reading and say "change sensor now"
I do NOT remove my sensor, but rather simply “start sensor”.
In 2 hours, enter your two BG readings and you are back on track.
it is only 2 hours out of the entire week,
I have mine “scheduled” to expire on Sunday late mornings.
Usually on day 7, I apply medical tape to the edges of where the sensor adhesive meets my skin. I find this helps it stick longer.
I have yet to go longer than 14 days, but may try to do so at some point.
Good luck and enjoy the obsessive viewing of the graphs!

Brett, Like Scott I also wait until it says “change sensor now”. It will start warning you that the sensor is about to expire hours before hand (I think 6 hours). You can, of course, stop and restart the sensor at any time that is convenient for you but I’ve found that waiting until it says “change sensor now” keeps me at basically the same time every time I start a new sensor, if I started it as soon as I got the expiration warning then it’d be 6 hours earlier every time and would definitely interfere with my life and/or sleep. So pretty much you can wait until it says “change sensor now” (at which point it automatically stops the sensor) or you can stop the sensor and restart it whenever it is convenient for you. Either way you will lose the 2 hours of data for the sensor to “warm up” but then you’ll be back to reading just fine.

Thanks Bryan!

I know what you mean about the obsessive viewing! I’m on information overload, but it’s so cool to see actual trends instead of just points!

Thanks Rebecca! I appreciate the help.

I use the routine described by the other members. I am currently using a sensor for the 17’th day. I had been changing on the 14’th day. Like some have said in other discussions, the agreement between Dex and meter is better the second week. So far, the third week is just as good as the second week. I read somewhere a Dexcom user used a sensor successfully for 24 days. The reason I had not gone this long previously is that I am concerned about developing scar tissue. I have a lot of scar tissue in my upper abdomen from more than 60 years of injections. I cannot use my pump or a sensor there. I want to avoid scar tissue on other body parts. There is very little agreement with my meter when my sensor is in scar tissue. I tried a sensor in scar tissue to experiment. i won’t do that again.

Great advice about the scar tissue, your posts are always super-informative!

IIRC, the Record for highest number of Dexcom days, before accuracy declined, is 32 (or maybe 33) “good” days.

Rick, I am not going to ever break t record. I don’t even want to. I am not conviced that leaving a sensor in my skin for so many days will not cause scar tissue. I am already unable to use my upper abdomen because of 60+ years of injections, most of which were in that part of my body. I cannot afford to lose more real estate because of scar tissue. My numbers are not so good today, the 18’th day for this sensor. I am starting a new one tomorrow.

That’s a good reason. I’ve taken to quitting at the end of the second week for several additional reasons, which I’ll list here:

First, it avoids the risk of failing to recognize “not so good numbers” as the Sensor begins to fail. (Which could occur at night, and could also happen away from home.) Second, it’s unlikely that I’ll have the replacement Sensor just “lying around” away from my home environment. I might not have a skin-prep pad either, and I definitely won’t have a portable hairdryer keep the drying skin-prep from flowing downwards as it dries. (That leads to an inconsistent layer of skin-prep, thinner at the top of the area. The top edge is the place where Dexcom Sensor pads usually fail.) And I definitely won’t have the big bottle of Povidone-Iodine which I use to disinfect.

Finally, of course, messing around with the 2-hour startup for only 2-4 days of additional readings isn’t worth the hassle, and it’s likely to occur at a time when you really wanted to be getting good readings.

Switching from one week to two cuts my co-pay costs in half, but switching from 14 to 17 days (typical) provides only 18% more savings-- which isn’t worth the risk and hassles for me. People with worse insurance, and/or less income, might want to push their Sensors to the very end; but for me, it isn’t worth it.

Thanks for the info guys. I’ve only been on the dexcom for a week, but it’s amazing. I’m really hoping to get my A1C down and cut down on nighttime hypos.

Thanks for the instructions Bryan, I am 4 weeks into the dex and restarted my sensor yesterday for an extension for the first time. So far right on target. Happy to be with Dex …mid nite wakes are annoying but comforting when the digits start to drop.