Extending a Medtronic Guardian Sensor

There’s no doubt that CGMs are amazing, but unfortunately they are also mind-blowingly expensive. In Germany, one box of five (5) sensors costs 349.50 EURO. That’s 69.90 Euro per sensor that only lasts six days. Anyway, one box of five is a one month supply – and that’s if you’re lucky and ALL sensors set correctly and are accurate for the full six days.

Even though my insurance covers 100% of the costs of my CGM, I still want to extend the use of my sensors each time in order to build stock. With that being said, the sensors are recommended and only approved for six days of use. 

Here’s how I extend the life of my sensors: 

1. Once the six days are up on my sensor, I let the pump tell me the sensor is finished.

2.  Now there are two options:

OPTION ONE: carefully take the over tape off and disconnect the transmitter from the sensor port. Recharge the transmitter. Once fully charged, simply reconnect it to the sensor.

OPTION TWO: carefully, as to not disturb the actual sensor area, separate the transmitter (clam shell) from the sensor port. Separate them by a few milliliters. I only had to slightly separate and then reconnect, all while the over tape was still in place.

3. Green lights should start flashing on the transmitter (clam shell)

4. Tell the pump that you’re starting a NEW SENSOR

5. Wait for the warm up to complete and calibrate as directed

That’s it. Depending on the battery life of the transmitter, or how much longer it will be used, I don’t even need to recharge it before starting a “new” sensor. The longest I’ve used a Guardian sensor so far is 15 days. Apart from obvious inaccuracy, I find that once the sensor starts giving error messages that it has no sensor glucose value, and when gaps show up on the graph, it’s time to change the sensor.

Do you use your sensors longer than six days? What techniques do you use? 

P.S. Use your own discretion, as mentioned, the sensor is only FDA approved for 6 days in the United States.



    1. I have also done this, usually for 10 – 14 days. Sometimes in the middle of the second week, I’ll get
      a calibrate message for a 6 hr calibration, like on the first day. Results tend to get wacky sometimes after that. But, here is the reason it is not recommended. The part of the sensor that goes into your body is a probe that measures the interstitial glucose level. Normally the body would destroy this probe, but Medtronic put a coating on it to protect it. The rub is that the body also starts to attack the coating after 6 – 7 days. I assume they built some safety margin into there use estimate. So extend at your own risk. In this case I think finance needs to trump safety.


  1. Thank you. Have had 2 weeks on Medtronic 370g and generally loving it. (Pumping with Animas/Dexcom for years) Will try the slight disconnect when sensor expires. Vielen dank! (Auch lerne iich Deutsch.) Like the sound of your health care system. In Australia those on welfare can get free pump/CGM but others pay. Works out to $50 a week plus ‘consumables’.

    Liked by 1 person

  2. I have had great success extending Guardian 3 sensors with my 670G. However, there is a probability of generating scar tissue by not moving sites.


    1. I use the medtronic 670g, and have been able to extend the sensors every week since Jan. this year. I always get 7 days out of the sensor and have been able to get between 5-6 days consistently on the second week. A few times I tried a third week and run it an additional 3-4 days but it did error a few times and requested a bg fairly often. I have also noticed that sometimes when I’m on the second week towards the end of the 2nd week it makes me calibrate every 6 hours instead of 12 but that seems like a small price to pay for an additional week of wear.
      I’m envious of the gentleman in Germany. I made it to 100% once but I doubt I’ll get there again this year. It’s discouraging. My FSA money is nearly gone and it’s only the end of April. I doubt I’ll have enough sensors to finish the year even at 2 weeks for each. Although it helps a TON!!

      Liked by 1 person

    2. I have also been able to extend a 670G Guardian sensor sometimes for another 7-10 days however, as someone else stated, you risk developing scar tissue which has a nasty way of biting you in the future.

      You need to remove the transmitter and recharge it fully. Then treat it as if it were a brand new one.


    1. I take that back. Tried again and it looks like it’s working. I disconnected transmitter and then reattached. Selected new sensor option. It made it to warm-up stage.


  3. Glad someone else has done this. Going to try this tomorrow when my sensor “expires” but I wanted to see if the pump would throw a fit.


  4. Thanks for the info. I just switched to a new Minimed pump and from the Dexcom CGM system. I used to get up to three weeks with the Dexcom sensors – also very easy to restart. Sure could use a way to extend the guardian sensors.


    1. Hello I have the 670G pump and my Guardian sensor lasts 7 days not 6 days. I too from day 1 have tried to extend life with sensor. Tried reusing did not work.


  5. Wait your insurance covers your CGM 100%
    Do you put tape over your transmitter? I tried but then can’t remove the transmitter to charge


    1. Yes, mine is 100% covered in Germany. They healthcare system is truly amazing. And yes, I use two pieces of the tape that it comes with. I don’t remove mine to charge until I get to the second reset on day 12. Mine has 70%+ battery left for the first reset so I don’t bother to take it off, just slightly disconnected like I wrote.

      Liked by 1 person

    2. we bought nail cutter scissors and cut around the transmitter and took it off. they are nice and sharp.


    3. Put the supplied tape over sensor. Put a piece of regular paper medical tape over transmitter plus attached tape. Makes it easy to remove transmitter. I like to recharge it before reinserting.

      Liked by 1 person

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