Medtronic 780G and Guardian 4

I have been using Medtronic pumps for over 20 yrs, currently the 630G and Dexcom sensor. My A1C is consistently around 6. I am on Medicare and due for an upgrade in 3 months. My physician is suggesting the 680G and Guardian 4. i am not so sure about the Guardian 4. Am I correct that you have to put in on your arm and it is hard to do without someone helping you?
It has to be changed every 7 days instead of Dexcom 10? I realize the Dexcom and Medtronic 780G are not compatible.
Should I forget my concerns about the Guardian 4 sensor or explore other options? Appreciate any thoughts.

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I suggest you always consider other options. I can’t speak relative to G4, but if you’re not happy with it, and want a pump that uses cgm input to adjust insulin, there are other options to explore.

I am happy with my Tandem X2 after many Medtronic pumps (50x to 523, no cgm integration). Omnipod is another option.

Maybe this option:

Its nice to have choices.

Hey there, I can only share what I have discovered over the last year. I’ve been reviewing Medtronic 780 comments from all over, including Europe.

I’m currently using a Medtronic 670G with G 3. I have had issues, but mainly good service since March. I have read so many great things about Medtronic 780 and G4! Some are getting 95% plus TIR! I would be glad with 80%. They tell me they love it and the G4 is fantastic. I just got mine and am preparing for the training now. It does take a couple of weeks to get it acclimated. I can’t speak for myself until I’ve used it a little while.

I’m sure other systems are great too, but after reading a lot about them all, I ended up with 780. I hope it’s all I anticapate.

With practice, I have learned to insert my sensors and attach transmitter with adhesives to my upper arms with one hand. I can even do it with my left, nondominate hand on the back if my right arm. It just takes practice. Granted, if you have any arthritis, it might be more difficult. I have read Medtronic has plans to modify the insertion, to make it easier. Not sure when that might happen though.

I hope you find one you really like.


The 780g system is unbelievably good! I’m not even using the G4 sensors yet. I still have G3 to use up. But the difference in this and before the upgrade is remarkable. I have days I’m in range 100%. And I went down from an A1C of 7.2 to 6.5 in a short time. I have same concerns with arm insertion but I’m sure if others can do it I can too.


I am on the 780 and G4. It works fantastic! You can wear the sensor wherever it works for you. I wear it in my stomach. Medtronic needs to say the arm because that is where it was testes for FDA approval. If you like to keep your control tight, this pump is for you. I was looking to move to T-slim and followed the facebook site on it for a long time but I’m glad I didn’t. Look on facebook for the 670/770/780 group. Keep in mind most people posting are having an issue, I would suggest you ask how people like it, they will come out of the woodwork with accolades for the pump.


I’m so glad to see these positive responses. I can barely wait to get trained and set up. Anyone want to describe their training?

Tried the G4 and just plain had to give up. I do not believe one person can possibly get the sensor & transmitter taped onto arm. Two of us attempted a number of times and finally had to give up. I had very high hopes/expectations for the G4 sensor and transmitter but had to go back to the Freestyle Libre 2.
Medicare must make improvements before I will ever try again.
I would definitely not recommend!!!

I suggest contacting Omnipod. They will give you a free trial and this won’t burn up your once every 5-year update. Going tubeless is a total game changer and much less studs to deal with when changing pump. Auto prime and auto insertion. Minimal supplies to carry around. I’m using Dexcom G7 with Loop on iPhone and it works great.

To answer your question, the G4 is much more difficult to put in relative to the other CGMs out there, ie, Dexcom and Abbott. Can it require a second person? Yes depending on your ability and dexterity to place on the back side of your arm.

The G4 main problem is application difficulty and the dreaded sensor updating problem. A large number of users have reported the sensor updating problem which ultimately causes your to remove and replace. This is quite annoying because it can happen at any time and can also occur well before day 7.

The cons of the G4 are the following:

-difficult application
-bulky application
-length of time to use
-does require finger stick at onset of entering Smartguard
-sensor updating problem
-30 minute charge added to 2 hour warmup

The sensor combined with the 780G is a very good pump system and you will see good improvements. Just keep in mind there are also other very good options out there.

The G4 sensor application appears identical to the G3. I’ve looked at a couple videos on it. Here’s a link for one.

i will say that the one tricky part that I addressed after seeing the tip online (not in this video, but one I saw years ago), is removing the second film of adhesive on the sensor while it’s still in the Serter device. While it’s still inside the Serter, before I insert into my arm, I gently lift the extra adhesive off the base adhesive…the flap adhesive remains, so you can remove it, just before you wrap it over the transmitter. That way, when it goes into my skin, it immediately sticks and I don’t need to gingerly pull it off while stuck on my arm. For me, that’s a super easy way to do it.

The rest, I got with practice. If I had dexterity issues, I could understand how that might be a factor. Hopefully, I’ll be able to report on my G4 experience before too long.

I am now on 780g and g4 sensor but have used g3s for years. I am able to use the back of my arm (either one) because I don’t used the provided tape. I use Simpatch that is easily applied with one hand by not peeling the backing off the two sides until the center is on over the sensor and transmitter. It doesn’t hurt to apply a bit of Skin Tac to the arm first. I wear a cut off athletic sock at night to protect the edges from rubbing on the sheets and unpeeling. I also set the inserter to place the sensor just on the inside of my arm to keep away from squeezing it between my arm and the bed. It doesn’t even reach my side if I lie on that arm.
If anyone is interested, I can detail how I am able to get more than 7 days with either g3 or g4 by restarting it without removing it. I easily get 10 days and more and don’t RandR until the sensor starts being inaccurate.
I love the 780’s auto mode (Smart guard) at night for sure and after only two months my a1C has come down to 6.7 from my previous low of 7. My only gripe is no correction boluses without lying about eating.

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@Mike3 ,

I extend my sensors too. I use the Medtronic adhesive piece for the sensor, but use a different SmithNephew IV frame adhesive to put over the transmitter. It allows for easier removal when I remove transmitter to recharge.
Is it possible to extend the G4 as well?

I used to get 2 weeks, maybe more, but not any longer. Now I only get about 10 days before odd things start happening.

I was super nervous about upgrading to the 780 and G4 transmitter and sensors. First off, they say the back of the arm because that’s where the fda testing is approved. You can put the sensor wherever you feel comfortable. (Just tell Medtronic it was in the arm if you have a failure!) I had to go 2 months with the 780 and G3 transmitter before I finally received my G4. No blood sugars!!! I couldn’t believe it. Of course I had to do a bs just to verify the sensor. But it was with in 10 points! I’m only a couple weeks in with the new sensor but so far very happy.


I have been using the 780G for a few months now and, in my opinion, it is really good. However, I am in Canada and the G4 is still not available here so I am still using the G3. I do agree with the comments of others, though, that application of the Medtronic sensors is nowhere near as easy as other sensors. In my opinion, the Freestyle Libre 2 is by far the best sensor and the simplest to apply. I really wish Medtronic would improve their sensors to be the simple “one click” application that Freestyle has.

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Hello, HighHopes. Does your SN IV come undone prematurely? If not, I’ll give it a try. What I do currently is as I apply my Simpatch, I cut to the shape of my transmitter a piece of the backing (middle that I remove first) with the shiniest side toward the transmitter to help it slide without sticking to the patch. When my week is up I first take my thumbnail and try to separate the xmitter from the sensor w/o moving the sensor. If I can’t separate it far enough to cause my pump display to go from BG value to dashes (indicating disconnected xmitter) I use a thin bladed screwdriver to continue the separation until that does occur. Total disconnection isn’t necessary or desired. It’s probably a bit less than a quarter inch. I then turn off my sensor on my pump and then turn it back on. Then I squeeze the xmitter back onto the sensor (again trying not to disturb the location of the sensor.) Within a minute the pump will alert and be sure you “start new sensor” and you’re on your way to a 2 hour warm up period. I find that it usually will last for 3,4 days or more until the sensor starts to give wonky readings. At the costs of sensors (even with insurance) it is definitely worth the little bit of extra effort on my part.
Any one else have ideas or work arounds. BTW, it works for either G3 or G4 sensors.

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I get what you describe in the extending. I guess my transmitter would last that long.

I think my SN IV frame adhesive hold pretty well. The plus is that when my 7 days is done, it can be removed without dislodging anything. For me it works. If I swam everyday, it might be different.

Years ago, I actually got over 2 weeks use out of one sensor. They don’t last that long anymore, though.

I just upgraded to the 780G yesterday and still have some G3 sensors to use up as well. Dumb question. Can you use Smart Guard with the G3, or do I need to wait until I transition to the G4 sensors? I have information overload at this point and can’t seem to pinpoint this!

You can use them as long as your pump has transmitter still in its settings. They work fine but with the G3 transmitter only. Pump upgrade improves the sensor experience in G3 too.

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I currently have the 770, and using Dex G7. My A1c is 5.8>6.0, TIR 88%. I tweak my temp basels and correction boluses based on trend arrows and rise rates. My DiaDoc suggested I switch to the 780 G4 system to make things easier. I have been skeptical, having read complaints and etc. I sometimes get tired with the constant attention to micromanaging my BG.
So I have some questions.

  1. Can you input your current basel settings? Or does the pump have to learn?
  2. How long does it take for the system to learn your basels? My basels change seasonally, and I have set basels for those changes.
  3. How often do you micro manage your temps and correction boluses?
  4. How does it control for exercise? I do a temp basel of 0% and will carb load before hand. I currently anticipate what my activity will be, and adjust my basel.
    Do suspend the program and take manual control for those times?
  5. Can you receive your readings on your phone?
  6. Does it work with xDrip+? I get my BG readings on my Galaxy watch from Dexcom via xDrip, and don’t want to give that up.

Can someone post the link to the facebook forum?

The comments here are the first really positive comments I have read. So I am willing to give it a try.


I am on the 780 and the g3. I find inserting the sensor in my thigh works best. I also don’t use their overtape. I use Hypafix transparent tape. I cut a piece big enough to cover the whole sensor. I round the corners so that they don’t fray. It is easy. I also am getting 85-100% daily on this pump.