Dexcom back to finger-stick: tips

T1D, MDI CGM user here. Once or twice per year, my last Dexcom sensor expires before my supplier can complete my replacement order. Several times I’ve had to use finger-stick tests for a couple of weeks. Here are my tips for you if you too need to do this:

  1. plan to test 4 times per day: breakfast, lunch, dinner, bedtime;
  2. inject a calculated dose of short-term insulin (e.g., Novolog) before each meal, and possibly at bed time.
  3. count carbohydrates;
  4. use your carbohydrate ratio (grams of carbs that 1 unit of insulin will handle) to calculate the doses;
    basic dose = grams of carb / carbohydrate ratio
  5. try to maintain a target glucose reading; for me it’s 120 mg/dl.
  6. at bedtime, you can take an additional dose if your glucose reading is too high above your target. if your glucose reading is below the target, drink some orange juice.
  7. if you use a long lasting insulin, such as lantus, only change your dose to respond to daily change. such as surprisingly high or low readings in the morning.

Or. You could restart your last sensor.


However also good to have backup plan to handle case without dexcom!!

@celdridge search this site for more info on sensor restarts. This can allow you to continue dexcom use, during order/supply gaps.

Will Do!


Here is the information for restarting.I have a huge back up supply now and I actually prefer a restarted sensor’s accuracy.

Here’s a link to the videos, a guitar pick is actually the easiest thing to use to remove a transmitter, it pops it out really easy.

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I agree, it makes sense to be able to function with meters. That is something I did for over 50 years, though fortunately that is now just a memory.

By the way, if your insurance gives you a hassle about buying test strips now that you have CGM, I suggest you get a OneTouch Ultra meter and purchase really excellent 3rd party affordable test strips " GenUltimate Blood Glucose Test Strips 250 Count" – on Amazon at this quantity they cost 36 cents US per strip, so many people can afford to purchase them without depending on insurance. As long as you set the meter code to what’s on the test-strip bottle, they are every bit as accurate as strips from the manufacturer.

In my experience, most G6 sensors are inaccurate during the 1st 24 hours, while restarted sensors are much more accurate after waiting the 2 hours and calibrating. While I like to build up a small supply of sensors in case there are delivery problems, the actual reason I do 1 restart per sensor is being able to avoid the 1st inaccurate 24 hours of a new sensor.

I am impressed that Dexcom has been able to fool the US FDA into believing G6 no longer needs calibration. Good for their shareholders. Not true, in my experience, most of the time, though I am always pleased when a new sensor needs very little calibration, which is about 10-20% of the time.

All that said, I just love my G6 CGM and view the above as a small price to pay for a far better technology than what preceeded it.

But for sure, I also recommend restarts to build up a small sensor inventory in case there are supply delays.

I just wish I could get at least one transmitter ahead for the same reason. I have seen the video on how to pry apart the G6 transmitter, unsolder the batteries and solder in new ones, then glue it all together. I actually could do that – been a ham radio operator for years and all that would be easy – but I just have not taken the time to extend the life of a G6 transmitter.

Based on reports about the upcoming G7, it appears they will thwart all restart attempts with that version, where the transmitter and sensor are combined and thrown away after 10 days (though they hope to exend that to something like 15 days).

Too bad about the G7 reports. Still, I love my Dexcom CGM. In the US, the problems are the very high non-insurance retail prices and how the insurance companies will not allow purchasing a backup inventory.

I am not naive – I know people get glucose monitoring products, don’t use them and sell them to make money. That is sad, and it spoils things for the rest of us…

This is only valid for the early transmitters, with ID 80 and 81.

I have had problems with my supplier refusing to mail my 90 days supply until day 91, which of course means that there is a gap in therapy of a few days while I wait for the order to process and ship. It’s absurd.

The good part is, this problem is easily fixable.

  1. There’s the sensor restart option, which is a bit tricky but widely considered an excellent workaround. (You have to save the 4-digit sensor code, but otherwise it’s pretty easy to do-- there are instructional Youtube videos about this)

  2. Dexcom is generally very good about replacing sensors, so if you have a sensor that “fails” (this can be anything from sensor error to not providing accurate results to simply causing you irritation under your skin), they will send a new one to you free of charge.

I’ve had new sensors provide wildly inaccurate readings for 24-48 hours and then stabilize, but Dexcom will send you a new sensor if you call in about this. So consider that if your sensor “fails” on day one, and then Dexcom gets you a new sensor on day 4, you’ve just bought yourself 6 days of extra sensor wear that can bridge the therapy gap that your DME refuses to address. If this happens a second time, you’ve bought yourself 12 days of buffer time.

I’ve replaced several sensors now, so I really don’t have this day 91 problem anymore. I’ve usually got a full sensor in reserve when I place my renewal now.

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Dexcom has gotten better (read worse) regarding restarts. At first I could often get an additional 10 days by restarting the sensor - sometimes more. Now I get 2 to 3 days, sometimes more, sometimes less, but I restart every single one and slowly build up a supply of extra sensors. I now have about 6 months back-up but it requires diligence.
The transmitter was easier. I just called my supplier and requested an extra to have on hand and they charged me $63.00 but no other hassle.
I also keep my infusion sets/reservoirs in longer than the 3 days and now have lots of those.