I am due for a 90 supply of Dexcom sensors. I am on a TSlim Tandem pump. I requested the new 15 day Dexcom sensor but was told it has not yet been approved for use with the TSlim pump. I called Tandem to confirm and was told it was true and they did not know when it would be approved. I was anxious to try it but will have to wait.
Thanks for letting us know. I asked my Endo and he advised to wait and see what the results are; I concurred based on the small print Dexcom finding only about 75% of users get the full 15-days offered. That I recall, only one other person here on FUD has the 15-day variety. What say other’s? If you’re a G7 15-Day user, please let us all know your experience…good, bad, indifferent?
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My experience is here:
Bottom line was it was functional for 12 days, so no major gain over the 10.5 days I get from the current G7.10 and potentially lots of pain.
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I ordered them for my next shipment, which I should be getting around the end of the month - I will report back after I try one! Thankfully I’m MDI so don’t have to worry about pump compatibility.
Part of the reason I stopped using my Tandem pump was because the Dexcom G7 sensors were so erratic, it was negatively affecting the pump’s ability to function well. Life has been MUCH easier and smoother using Lantus & Fiasp!
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I am still using the G6 but recently received a message they will not be available after June 2026. My Endo recommended remaining with the G6 as other users in his practice were always reporting problems. I plan on moving to G7 10 day until insurance says I cannot use them or they discontinue them too. I have several reasons for this. 1 - the literature only shows a very slight increase in accuracy of the 15 day vs 10 day sensors. 2 - I find the adhesive tabs on the current G6 are generally ready to come off by day 10, and sometimes have to apply an over patch to achieve that. 3 - On occasion, I place a sensor in an area that is more tender or more likely to give compression lows and know I have to live with it for 10 days, but at least its not 15 days. 4 - the literature shows that the warmup time for the 10 day sensor is 30 minutes vs 60 minutes for the 15 day sensor (still, both are better than 2 hours) but I don’t like the extended warmup time. 5 - For me, the cost will be the same regardless of 2 per month or 3 per month.
I know the G6 was only approved for use on the abdomen. However, I found out that sensors placed there only lasted 7-8 days for me. After many replacements I decided to try the back of my arms and had much better success keeping them on for 10 days there and with improved accuracy and fewer signal losses.
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If you do it right, the warmup time is less than 5 minutes. Just insert the new G7-10day a half hour before you want to start using it, but don’t start it in the app. The old sensor will continue reporting BG. After the half hour has passed, you can start the new sensor and it will start reporting BG within 5 minutes because it already has been warming up for a half hour. Similarly, for the G7-15day put it in an hour before you want to start it in the app, and it will warm up all by itself while the old sensor keeps giving BG readings.
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I second @bkh’s method! I’ve been doing it like this for some time, using part of the grace period. Believe the 15-day version will allow the same thing, though would have to provide for an hour, vice 30 minutes. Have to admit this last G7 has had issues, time outs and sudden drops (20-50 pts) that correct on the next read (almost always at night so alarm wakes me up; almost swapped it out last night but wanted to sleep more!). Have enjoyed not having many issues for several months, hope its not a trend!
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What if I insert the new G7 (I don’t think 10 or 15 day matters) 12 hours before I want it to become “active”? Will it have been warming up for all of those 12 hours? (I think both 10 + 15 day G7s give you a 12 hour freebie?) I simply do not trust any Dexcom sensor to go into my body and immediately begin reporting correct numbers – I am guessing I will always need a half-day warm up (“soak”). Thanks - j
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Yes. Presoaking uses up some of the lifetime of the sensor, but for me it’s worth it to get past some of the worst portion of the sensor data.
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I don’t understand why - if you haven’t yet activated the newly placed sensor - you will be using up some of the new sensor’s “lifetime”. Can you explain? Seems that the 10 or 15 day plus 12 hours countdown should begin upon the activation rather than the insertion moment.
The G7 sensor has a magnetic switch inside, which triggers when the sensor is removed from the inserter. You can see the small silver magnet that remains in the inserter. When the senser leaves the magnet in the inserter, the electronics in the G7 starts a clock, and the sensor stops itself after that 10 days + 12 hours has passed (for the 10-day version of the G7, of course). That timer in the sensor doesn’t care whether any app on a phone or in a Dexcom receiver is listening or has “activated” anything.
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Just started my second G7-15 day sensor. This time I placed it in my abdomen at 7:39am but did not activate it until about 8:18 am (when prior 12-hour grace period ended) at which time Dexcom stated that I had only 15 minutes remaining in the warmup period! So I guess that the sensor was already being recognized by the app despite its not having been activated yet?!
Got it, thanks - I neglected to look for your reply before placing my last reply (oops)
I ran into something similar when newer sensors came out, and yeah it’s frustrating when they’re not compatible right away. Good thing you checked first, that probably saved you a lot of hassle.
Hopefully approval comes through soon since the longer wear sounds really convenient. Anyone else waiting on this?
From what I understand, the Dexcom G7 has about a 30 minute warm up before it starts showing readings. It doesn’t really “pre warm” if you insert it early, it only starts working once activated.
That said, a lot of people feel like the first few hours can still be a bit less stable, so some prefer to start a new sensor when they’re not relying on it as much.
Curious if anyone has found a routine that makes day one smoother
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The word most use is "presoak"or just soak the sensor, not pre warm. This is inserting it 12 to 24 hours before starting. The idea is to limit the wonky readings that often occur on day one after starting. This was a common practice with G6 and maybe earlier models.
It was not something I could do because my G6 sensors often went stupid around day 7-8. I did your soaking a few times and had sensors go stupid a day earlier.
Now I am not sure if you soak a G7 if the timer starts upon insertion or if only when started. The circuitry for transmitting bluetooth begins immediately upon insertion, but the clock may not start until paired.
I don’t presoak G7 as well. It would be an interesting experiment to try it and see if the sensor and app begin to intermittently lose connectivity as day 10 or 15 approaches. This could indicate that the battery strength was weakened by the presoak time.
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Folks, as long as the G7 is working as designed, it starts a timer when the sensor departs from the applicator as @bkh described it. If you look at the applicator post application, you’ll see a small silver magnet, when the sensor is in the applicator, that magnet prevents the sensor from activating. When the sensor is applied (i.e. the sensor is separated from that magnet), a timer count begin’s and the sensor is good for 10.5 days or 15.5 days (depending on whether a 10-day or 15-day version). It doesn’t matter whether you “let it soak” before inserting the sensor code or insert the code immediately to your phone/pdm, the timer/counter will still be operating and when the 10.5 or 15.5 day count is reached it will stop working. The “soaking” time and the code insertion time just don’t matter, the sensor is using battery life to make readings whether used or not. As long as everything is working as designed, activation is automatic and has nothing to do with the phone or pdm. The phone/pdm are reporting mechanisms only.
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TomH is right. The timer starts on insertion and the readings start 30 minutes later unless there’s a malfunction with the magnet which used to happen but seems rarer now. The readings are active whether there is a reading device connected or not.
My routine is to insert at night on the last night my previous sensor will give readings. I don’t connect to the new sensors readings because I don’t want to be woken in the night by a false low and instead rely on my expiring sensor. In the morning, I connect to the new sensor as my old one expires sometimes having them overlap a bit to see if they agree (by having my Dexcom app connect to the new sensor and my Tandem app still read the old sensor). In this way, I use up my 12 hour grace period with an overnight soak and still have a 10-day sensor.
If I switch between a G6 and a G7 as I’ve sometimes done, I can see all the G7’s overnight “silent” readings retroactively on the Sugarmate app which is sort of interesting and proof that if a G7 is reading in the night and there’s no app there to hear it, it does indeed make a sound (ie measure your glucose).
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Yeah, that’s frustrating. Pump integrations usually lag behind CGM updates. Hopefully Tandem approves it soon. Would be nice to get that extra wear time.
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