Metformin and t1

When first diagnosed with diabetes I was on metformin, shortly was found to be type one and bargain a life on insulin. I love to read and research and liked the fact that metformin helps us use insulin more effectively, so I stayed on metformin and insulin and had pretty good control but ultimately stopped. 20 years later my t1 is not so easy to control (understatement) and have not thought much about metformin in awhile. Anyone using both and what is your opinion as well as anyone else who has one. Dont see my CDE until February would like to have an opinion by then.
As always thanks for ANY imput.

im on an insulin pump and on metformin. i see it helps me use less insulin than before. my basal rates has decreased as well. so i see a big difference in my using it.

I was on pump but lost transmitter (fell off at work somewhere) 530g with enlite. Am trying to get new and start again, a member here found me one on eBay that I am going to try and get (so thankfull) think I am going to email my code tomorrow and see about giving it a try (metformin) thanks for the input an have a safe, enjoyable and steady new years.

I am long time T1D, and started using metformin after cancer diagnosis. Some studies show benefits related to cancer. I have noticed since using metformin that BGs respond more quickly to insulin and easier to control weight. A1C about the same, but increased time in range (less highs and lows).

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I stopped using about 5 years before cancer and heart attack. Will have to check out that article. Thanks, have been fighting trying to get back in range and unfortunately have forgotten most of what I knew about diabetes, think 900mg of gabapentin a day for last 4 or 5 years didn’t help. Like to say I can’t remember when I lost my memory. My cde last time I saw her said I need to carry a little notebook to Wright things down and I told her I did but I keep losing them so I put everything on phone now. Any ways I am going to try again and check out that link, thanks

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I’m in my 30s and have had T1D since childhood and started taking metformin a couple years ago. I started it in hopes that it would help with extreme swings in insulin sensitivity/resistance caused by hormones. I haven’t noticed any benefit there, but I do think the metformin helps insulin to turn highs around a bit faster, it basically eliminated my dawn phenomenon, and for the first time in years I was able to lose a few pounds. I haven’t noticed any change in insulin dose, but whenever I miss a dose, I do run quite high for that day, so I think it must be having some effect. I have heard it has positive benefits on cancer, heart disease, aging, so I plan on continuing to take it. I even had low Vitamin B12, which is a known side effect, and asked my endocrinologist if I should stop taking it. I thought he would say yes, and was quite surprised when he said that I should continue to take it if it was helping my diabetes control, and just take a daily B12 supplement.


I am hoping for help with swings at 7:00pm after dinner I was 239 just now 397, but I am also dealing with flu/bad cold so that really helps out.

I’ve heard some people say that they find metformin allows them to never go above 300 mg/dl. That hasn’t been the case for me; I’ll still hit 500+ mg/dl if I have a bad site… But with Fiasp, I do find if I can correct a high as it’s just crossing the upper bounds of my target range, it turns around nearly instantly. I did start Fiasp at around the same time as I stated metformin, so it’s hard to tell for sure where the effect comes from, but I think the metformin helps given that I go quite high if I forget to take it.

Just want to say THANK YOU to everyone for replying it means alot, can only hope I can some day help someone in there wheat to control the deacon we all love.

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I have used both for years. When I take metformin the same time as the insulin, I see a positive effect. Metformin taken later or earlier than insulin not much of an effect. You should have your liver checked to be sure that metformin is not having a negative effect. I take 850 3x a day. The metformin ER did not work well for me.

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I started taking metformin about 3 months ago because my cde thought it would help me lose weight. I started at dosage 500, and saw no difference in anything, no weight change or insulin change. They upped the dosage to 1000, and I instantly cut my tdd from 50 units to 40 units, and i lost 5 pounds over the next 5 weeks. The sugars seem to be just as difficult to manage, but I’m happy with the weight and insulin reduction. I just hope it stays this way (fingers crossed).


I’m LADA. I took metformin ER when I was originally misdiagnosed as T2, and it was really screwing up my energy levels. My understanding is that part of how metformin works is by interfering with the liver supplying glucagon/glucose when the body needs it, thus reducing BG. This strikes me as a bad idea for T1s, where the liver is needed in case of a hypo.

I felt much better after I was correctly diagnosed and switched from metformin to insulin.

My liver hasn’t responded to a low in a very, very long time. For many type 1s, the pancreas no longer dumps glucagon to signal to the liver that glucose is needed. The alpha cells that have this job are either not working properly or died along with the beta cells. If this still worked properly, we wouldn’t need to worry near as much about lows.

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T1 for 35 yrs, I started taking Metformin back when I was on MDI to help deal with dawn phenomenon. Helped a bit. Thought I might go off it when I switched to a pump (the real fix for DP) but my endo said to stay with it, because it helps reduce TDD and the less insulin you have to take the easier it is to deal with. I’ve recently started taking Jardiance as well, also off-label for T1, but it has been pretty amazing in steadying my BG and (also) lowering TDD.

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Same here. My understanding is the longer one has diabetes, the less the liver tends to respond to lows. I certainly would never rely on mine to save my life. I’ve had lows last up to nine hours on my CGM without a blip of help from my liver (T1D for 27 years, though even as a kid I had bad hypoglycemia unawareness).

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I’m not trying to be argumentative. I’m relatively new at this and want to make sure I understand. Isn’t the stereotypical hypo response of jittery and sweaty the result of the liver dumping glucagon? If so, and you are no longer having the liver do this for you, does that mean you have hypo-unawareness?

Separately, if a T1 is using a CGM, it should be less important that the liver be able to respond to a hypo, as the CGM can alert the user to manually intervene (and eat some carbs).

Am I still missing something?

My understanding is that the symptoms of hypoglycemia are actually caused by epinephrine from the adrenal gland.

I haven’t read this whole article, but the first few paragraphs seem to explain the situation pretty well:

"People who don’t have diabetes have a number of defense mechanisms against hypoglycemia. First, the pancreas decreases its insulin output, allowing blood glucose to rise. Second, the alpha cells of the pancreas secrete the counterregulatory hormone glucagon, which signals the liver to release more glucose. Third, the adrenal glands secrete epinephrine, which signals the liver and kidneys to produce more glucose; in addition, epinephrine keeps certain body tissues, such as muscle, from using as much glucose from the bloodstream, and it acts to reduce insulin secretion. Epinephrine is the same “fight or flight” hormone that revs the body up in response to danger, and it produces the symptoms that normally herald an episode of hypoglycemia, such as hunger, sweating, trembling, “butterflies,” and heart palpitations. In some cases, especially when glucagon and epinephrine fail to adequately raise blood glucose levels, the body releases cortisol and growth hormone, which can also increase blood glucose levels.

After years of having Type 1 diabetes, many individuals lose most of these defenses against hypoglycemia. To begin with, they are not able to benefit from reduced secretion of insulin by the pancreas; the reason why people with Type 1 diabetes must use injected or infused insulin is that the pancreas no longer makes insulin at all. Also, for reasons unknown, people with Type 1 diabetes usually lose their ability to secrete glucagon. In addition, after recurring episodes of even mild hypoglycemia, the epinephrine response gets blunted — in other words, blood sugar must drop lower before epinephrine gets secreted."

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I don’t really know how much glucose the liver is supposed to secrete when epinephrine sends this signal though. I still have hypoglycemia awareness, but that doesn’t seem to help raise my bg at all when I’m low.

On the other hand, a shot of glucagon would raise my bg substantially.

I agree that a cgm can help significantly. I feel so fortunate to be able to use one of these so I can prevent/limit severe lows.

I took metformin for about a year. I finally gave it up. I didn’t lose any weight and it did nothing to help my control. I got so sick of running to the bathroom. I feel a lot better without it.

I was on insulin (MDI) and metformin for 9 years, while I was still being treated as T2. It didn’t seem to do anything for BGs. It apparently gave me fatty liver, but before I started insulin. Was also taking Victoza much of that time. Victoza did help level out BGs.

CGM and insulin pump has been much better, especially since changing insulin to FIASP.