Medtronic 780G

When you describe the 48 hour warm up that awakes you at midnight, do you mean that only happens once, when you first start the pump? Or, will this happen on a regular basis?

I hope the reservoirs I am using with my 670G will work with 780G.

I’ll look forward to seeing your progress!

@HighHopes … it is my understanding is that the 48 hour thing is a 1-time happening. After that, it is just the normal sensor warmup (2 hours for the G4).

While i cant say 100%, i believe that the 670 uses the same physical chasis, just different ‘guts’ from the 770G/780G. So I believe that 670 reservoirs should work fine, but maybe someone else has more recent experience moving from a 670G to a 770G.

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I hope so. I got a good deal on the reservoirs and hope to use them. If not, I can keep them to use use as backup with my 670G. I intend to keep my old pump as backup, instead of turning in for $500. Credit.

I have a tslim x2 through my pharmacy benefits, and a 780G through my medical benefits.

I have been using the 780G to see if the experience is better since the 770G and the horrible CGM G3.

I would say the experience overall is much better than the 770G mostly due to the G4. I would say the algorithms ability to drive you down to the target is an issue of contention. Smartguard will start off so safe and you will spend lots of time in undesirable ranges, 130 to 140. Eventually it begins to work more efficiently as it learns your basal needs.

I don’t think the target 110 versus 100 is much of an advantage because Smartguard is so safe about getting you to the target that you rarely spend time there except when sleeping.

The G4 still sucks in comparison to the Dexcom. It’s harder to put on. Typically still needs 1 to 4 calibrations through the 7 days. The transmitter has to be charged for 45 minutes, and then you have a 2 hour warmup.

The 48 hour warmup period is required anytime the pump has been turned off for greater than 2 weeks. If turned off less than 2 weeks it requires a 5 hour warmup. This does seem ridiculous, and actually is somewhat but the algorithm is gathering data on your insulin needs. You have to understand that Smartguard literally does not use your basal profiles for anything. It develops its own basal profile. The only thing the algorithm users which is user defined is carb ratio and active insulin time. The lower you go the more aggressive it will be. Example, 2 hours active insulin time will be more aggressive than 3 hours.

The true advantage of the Smart guard algorithm is that you don’t need to build out basal profiles. It determines your basal needs automatically.

Control IQ needs improvements as it’s becoming more dated, however, I still think it holds advantage of you are willing to get your basal profiles right.

My last A1C after using control IQ for 3 months was 5.6. I’m going to use Smartguard for 3 months to determine if I get a lower A1C. I doubt I will achieve that because Smartguard cares more about time in range than the drive towards the target.

Interestingly enough, when I was on MDI my A1C was between 5.6 and 5.9. To me pumping does comes down to convenience and more time in range. Which one is the most convenient for you? They both have great advantages. In the end, the algorithms are essentially the same in regard to control and Time in Range so begin looking at other factors in my opinion. Dexcom vs G4. Size. Charging va batteries. Mobile bolusing. Extended infusion sets. IPX7 vs IPX8. Price. PEACE OF MIND.


@Rav8es , I don’t intend to turn my pump off at all, so a long warm up doesn’t bother me.

Are you saying the cgm requires calibrations throughout the week or the pump request that you enter a BG? I thought G4 did not require calibration except after the change of the sensor.

I’m using G3 now and it’s great. Numbers are close to finger stick and I get full weeks service and even extend mine. I think different people get different experiences. I used to have issues with 670G, but then it settled down. I’m not sure why.

How about Temp Target…is that available? I like auto-control, as I don’t do well on set basal settings. I do need a way to lighten up if I’m exercising or drinking.

Are you saying there is no way to exit auto control on 780G? Can’t you just stay in manual mode?

I still can’t find enough cause to lead me from Medtronic 780G and G4 yet. I haven’t ordered it yet, but expect to any day. What is your biggest issue with it?

Regarding calibrations. I use Dexcom G6 for my tslim x2, and G4 for my 780G. When I decided to give Medtronic another shot with the 780G, I was actually wearing a G6 on my right upper arm and a G4 on my left upper arm. In the 1st 3 days, there were multiple instances where the G4 was reading up to 40 mg/dl higher than the G6, and then I confirmed it by taking my blood sugar. I had to calibrate up to 4 times and then it was fine after that for the remaining days. The calibration wasn’t required by the pump though, that was something I did proactively. I honestly had the same issues with the G3, except it required multiple calibrations up front and then once every 12 hours and I just couldn’t stand it. Plus there was no way I was willing to use 120 mg/dl target with the 770G, so I was in manual mode constantly getting suspend before low alarms.

The 780G can be ran in manual mode and you can exit auto mode. Manual mode will use your basil profiles as normal, Smartguard does not use your basal profiles at all. It actually takes time for it to be able to control your blood sugar because it has to log trends and then react differently to those trends day to day as it updates at midnight. If you turn the pump off for less than 2 weeks, you will have a 5 hour Smartguard warmup. If it is turned off for more than 2 weeks, Smartguard requires a 48 hour warmup.

In my opinion, Control IQ and SmartGuard give you pretty close to equivalent control and TIR. They both have advantages. The main factor for me wanting to give the 780G/Medtronic another shot is the 100 mg/dl target. However, you will soon find out it is very cautious about taking you to that target that I highly doubt I will get any advantage. You have far more control with control IQ because it does consider your basil profiles. If you have really good basil profiles like me, you may tend to want to use control IQ and combine with dexcom. Again I find they both have different pros and cons that make them stand out, however, bottom line is peace of mind and unfortunately cost. On the flip side, for people who never really built out good basil profiles, Smartguard will help.

My biggest issues with the 780G are these:
-The G4 is better but still no comparison to dexcom. It’s better only because no calibrations are required (but that doesn’t mean they aren’t necessarily needed). The tape process and the lack of precision and accuracy make it bad. Sometimes I find myself having to ask my wife for help quite often. You have a 2 hour warmup, 45 minute charge. The G7 upcoming with tslim you have 30 minute warmup, but since the transmitter is built in you can overlap and have no warmup. To me Medtronic forcing the G4 on users is about money and profit rather than actual benefits for T1Ds.
-The pump has a large form factor. I enjoy the reservoir and the IPX8 rating, but it’s just a little big honestly.
-No mobile bolusing. I can’t tell you how much I love this feature with my tslim x2. It’s already bad enough have to press buttons to go through the menu to bolus, especially when you have a lot going on. With the mobile bolus feature it usually creates less stress on me and I can be discrete. Sometimes you just don’t want to to talk to others about your health condition. When they see a pump and tubing, many people are curious and ask which isn’t necessarily a bad thing, but sometimes you just don’t want to go through it and just be discrete.
-Lack of dexcom or other cgm integration. I find most pharmacy benefits cover dexcom, but won’t cover G4. I always have to run G4 through DME. More cost, average deductible in USA is between 2000-2500.

The things I like about the 780G:
-Smartguard is really great in the sense that you don’t have to worry about it. It will figure you out and keep you in range at least for me. It gives bolusing every 5 minutes as needed when sugar are above 120 mg/dl and as I’ve stated the basal rates are automatic.
-IPX8. I shower with my pump on and get in the hot tub etc. tslim currently is only IPX7.
-Extended infusion sets. I change the CGM and the infusion set every 7 days together.

Again they both have advantages and are really good pumps. What a time to be alive for T1Ds.


@Rav8es ,
That’s a really good comparison. I appreciate it. I will explore the points you make, especially after the warm up. For some reason I spike when waiting for warm up. It’s weird.

I can’t imagine ever doing a remote bolus, so luckily that doesn’t bother me. I’m proud of my pump and cgm and embrace the chance to share, if anyone ask. With my work, a medical device is accepted, but using a phone would get negative attention.

I liked how you wore both cgms at once. I did that years ago when I first got my pump. I had been using Dexcom G5 and still had a sensor, so used it for as long as I could along with the Medtronic G3. They were about the same almost all the time. Over the last 4 months, even though my transmitter is old, it’s pretty accurate. So, I hope the G4 will be that way too. And, from what I read, Tslim isn’t that great, so, I’m still leaning towards Medtronic.

Thanks again for your thoughtful posts. Please continue to report your findings.

This is my third Guardian 4 that I have used so far. No dexcom this time. After going through the warm up, I have a blood sugar reading of 51. I knew for a fact it’s not true, because I didn’t feel it. I took my blood sugar and it ran 135. It didn’t accept the calibration, and said wait 15 minutes to calibrate again. I took my blood sugar again, and it was 139. I calibrated, and it rejected. Now it says wait 2 hours, and then calibrate again.

When this happens with dexcom, I usually do partial bg calibration.

For example, if off by 60 points, first do +/- 30 points. Repeat after 5-10 minutes.

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@Rav8es , thats so frustrating. I hate it when that happens. I really wish they could figure out a way this type of thing wouldn’t happen.

One factor is how hydrated you are. Be sure to drink enough fluids/water, especially in hot weather.

@MM1 ,
That’s a good point. I try to keep that in mind and drink lots of water. In fact, I drink only water now, with the exception of limited coffee and almond milk. (Juice for lows) How much water is enough?

Google search!!!

I loved reading this! It is my experienced exactly! I hope to have a 780G within a couple of weeks. Thank you for your posts!

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Well, I started this thread 3 months ago, and haven’t been back much since. Life does tend to take over sometimes, doesn’t it?!?

It’s probably turned out to be a good thing that I waited a bit to give impressions of the 780. SmartGuard is a learning algorithm … it gets better at it’s job the longer you use it. And I found this to be true. At the start, my readings were fairly inconsistent, and hard to predict. It was frustrating, and I was about to give up on it, as I had pretty good results with my t:slim-x2. But, the longer I stayed with it, the better my results. For the month of August, my TIR was 94% (10-15% higher than my t:slim days)! And, my GMI (Glucose Management Indicator … essentially the equivalent of your A1C) has been running a few points lower than when on the t:slim. Obviously, both make me (and my endo) very happy.

For me, the accuracy of the G4 sensors have been great (have had a couple of problems, on which I’ll elaborate in a bit). As soon as I attach the transmitter to the sensor, the pump almost immediately recognizes it. I have only had two sensors that required a calibration after the initial warm-up. I periodically have been checking the sensor readings against finger-sticks, and they are right on for me. Most of the new G4s that I have used have not required any calibrations. Very pleased with that.

While accuracy has been great with the G4, I still hate how cumbersome it is to put on a new one … pulling out the needle (without pulling off the new sensor), multiple tapings, pulling multiple pieces of paper off of the various ‘sticky’ parts. This is especially true due to the only supported location is in the arm – very, very difficult (virtually impossible) to do with one hand by yourself. I know that some have been able to do it alone, but it ain’t easy, folks. Guess I got spoiled by the ease of use for the Dexcom … but the amount of wasted materials that you just throw in the trash with the Dexcom was disappointing. Very little waste with the G4. This insertion hassle should be taken care of once the upcoming Instinct CGM finally gets here.

During August, I have had three instances when the pump lost connection to the sensor/transmitter 1-2 days early. I do not believe that it was a radio communication problem (as happened a lot with the t:slim), since moving the pump closer to the sensor didn’t improve anything. The first and third time, I had to un-pair the transmitter from the pump, and re-pair it. Everything was just fine after that. Medtronic is sending me new sensors to replace them … even though the failure happened with just 1 or 2 days remaining, so good on Medtronic for that. If it happens again, they will replace the transmitter.

I do miss the remote bolus from the app … when it worked with the t:slim. The Bluetooth on the t:slim is so bad/weak, that the app lost communication to the pump (and the pump to the sensor) quite often. The weak Bluetooth is a huge knock on the t:slim, IMHO. You practically have to duct tape the pump on top of the Dexcom sensor for connection to not be lost between the pump & sensor. If you wore the pump on your belt on the left side of your body, it would not consistently communicate if the Dexcom was inserted on the right arm. Bluetooth on the 780 is much better, and connection between the pump and phone (and the pump to the sensor) has not been an issue at all.

So far, I am quite pleased with the 780G. While Control-IQ was a big improvement from the Medtronic 770G, the auto-bolusing of SmartGuard on the 780G makes it far superior for me. Despite the impression of some of Medtronic’s marketing materials, the 780’s auto-bolusing feature it is not a substitute for manual meal blousing. But it is still a tremendous step forward. I also wish that the auto-bolusing was a bit more aggressive than it is.

The comparatively low amount of material waste and no insulin waste (compared with the t:slim & Dexcom … which had huge amounts of both) is also a big winner for me.

Will be very happy once the mobile app gets upgraded to allow remote blousing, and the new Instinct CGM hits the street (both sometime late 2023/early 2024, or so I have heard). So far, quite happy with the switch.


This thread was helpful to me as a former Medtronic, now TSlim, possible return to MT. It is such a tough choice - for me.
On the small white dot for the needle, I too find I need to find “the spot” or my insulin syringe won’t budge to push insulin into the cartridge. As I have said before, I pull out the air before filling the syringe with insulin. Seems silly to do it with a syringe full of insulin. So that is two insertions. I hope to talk with a Medtronic staffer before long. I wanted the CIQ to work but it doesn’t do well with my lows.
I appreciate the details of the 780 users.
The cgm is the big issue for me. I do like the Dex. If only we could take parts of each system!!

I have always had fairly good success with the Guardian sensors, but i know i am in the minority. It seems thst Medtronic has always had a tough time making sensors successfully. Especially when starting to develop the 780, I always wondered why Medtronic didn’t just give up the sensor struggle and just partner with Dexcom. I really wish they had done so.

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@RLR56, i appreciate that update. I have decided to get the update of the 780 and G4. I do wish there was an online demonstration of the sensor installation you describe.

Congrats on your improved TIR. That’s what I’m looking forward to.

@HighHopes Here are a couple of videos. The first one is from Medtronic:

This next one is from a real person that is doing it by himself. He makes it look really easy. But I can tell you from experience, it is not easy at all (and almost impossible for me) to do it by yourself. His hands are obviously much more dexterous that mine are. Good for him, but I think that most people over 50 will have much more trouble than he does is performing this task alone. I know that my hands do not work as smoothly as his!

Good luck.

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