Metformin and ketosis issues

I ate loads of carbohydrates, and very little else, as a child and young adult, and was sedentary. As a result, I got type 2 diabetes. Now, as a 74-year-old, I am dealing with high BG in the mornings, but more reasonable readings later in the day.

I think the problem is with Metformin, which I’m currently taking at 1000mg per day.

In addition, I’m eating a ketogenic diet and it should be working. My BG readings should be lower. They are never below 110.

About a half year ago I was on the maximum Metformin dosage (2000mg), and my BGs were high all the time. My doctor wanted to move on to stronger medicines, eventually ending up with insulin.

I decided this couldn’t go on, and I went on a ketogenic diet.

With my doctor’s permission, I reduced my Metformin over a month or so while starting my diet. It took 3-4 months, so I had to be very patient, but I achieved readings from 110-120 in the morning, and normal A1C readings. My peripheral neuropathy (tingling and numbness) began to reverse.

I decided to add Metformin back after awhile, but I’m wondering if it is causing long-term insulin resistance and causing morning readings as high as 163. My doctor wants me to take more Metformin.

Yes, I’m in ketosis. My net carbs are below about 20 per day. My doctor says he doesn’t really understand ketosis, but he knows that Metformin is good for me.

I’m also worried about Metformin damaging my kidneys, as they already are at 50% functioning, probably due to cancer chemotherapy a couple of years ago.

Anyone have any expert insights into whether I should take Metformin while in ketosis and with kidney disease? No guesses, please. I can guess enough by myself :slight_smile: .

The best anyone can do is guess unfortunately David. Having given that caveat, I have heard that being in ketosis can actually raise fasting blood glucose. What I’ve heard as the explanation is insulin resistance, a term or concept I do not 100% agree with, in this case. Rather, I might put it another way. Since you’re not on insulin or anything else, then you are probably still capable of producing some insulin. On a ketogenic diet, you are not needing so much insulin so your pancreas is not putting it out like you would be, probably, on a non-ketogenic diet. No matter how “deranged” (it’s actually a medical term!) your metabolic system may be on a non-keto diet, it would still likely be producing some insulin. Therefore, you have nothing with which to clear your blood glucose.

And that’s my best (educated) guess.

Go see a doctor or another medical professional who understands about ketosis

Thanks for your guess. What does it mean for taking Metformin?

I suppose that makes sense. But I suspect that the only real expert on these topics who is a doctor or researcher is either impractical to locate or expensive to visit, because there is just one of them! Besides, we’re not supposed to travel these days. I doubt that an expert would just happen to live in my home town.


Not professional opinion, just a 74 T2 diagnosed 11 years ago at 12.0 now well controlled diet and exercise only A!c less than 6.0. 30 carbs of less. This relates only for me, but after two years of metformin I dropped it and my management leveled off and continued stable fo 9 years. Yes talk with your doctor, but listen to your body. A

Well, it is easy to write one word, isn’t it? I run Zoom meetings myself, so I’m ready to interact with an expert. The problem is finding one, isn’t it?

T2Tom, Thanks, this is very useful because it is an actual experience of a person taking Metformin. I consider your experience a support for my idea of coming off of Metformin, in opposition to the advice of my primary care physician, who is not an expert in these matters.

Sometimes, as TV dramas teach, doctors have fixed ideas that don’t take all the specific factors of a situation into consideration. I say this even as someone who has a great respect for doctors, my father having been one.

I am not in your category, good luck figuring out your diabetic puzzle.
Have you considered after all this you see an endo? Be safe. Nancy50

Yes it is easy to write one word, and because of your comment – “we’re not supposed to travel these days.” – I uttered it

Best of luck.

Do you mean endoscopy? What does that have to do with my question? None of my doctors know much about ketosis; I’ve asked them.

No, I am referring to an Endocrinologist who specializes in disease like Diabetes. As keto is such a popular way of controlling blood sugars I am sure they are informed more than a family practice provider. We are all so unique in how our body responds to this disease . Be safe!,Nancy50

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Your reply not only reflects your experience with Type 1, it also ignores the actual question I asked, which is not “what does Metformin do?” but how do Metformin and a ketogenic diet interact.

Thank you. Best of luck to all of us in these difficult times.

I agree with Nancy50 You need an endochrinologist. A family doctor doesn’t know anything in comparison. I am 61, a T2 diabetic on Metformin (1000mg/day) AND follow a ketogenic diet. In the last year, I have been working hard to eliminate meds and improve my health – including my diabetes and my liver health. The keto diet is about stopping the sugar, stopping the processed foods, watching amounts and I personally (that means LISTEN to your body) because of gastroparesis eat OMAD. I have lost over 150 pounds. I am off the Bydurian shots and Jardience and the next step is to reduce the Metformin. My A1C last time was 4.8 and this today was 4.7. Today my visit with my endo was online with a video meeting. It went beautifully. So yes, it is possible and insurance will pay for it. All my bloodwork was awesome/in the brackets as we say. I recommend an endochrinologist. I highly recommend a KETO diet (I don’t have a gall bladder, and still works very well). I suggest you reduce and if possible eliminate the Metformin – that’s my goal and my endo supports it. Less meds are always good. I am not experiencing morning spikes - with KETO and Metformin I have a consistent 80-90 BS in the morning. I am not an expert, but that is my experience and we match up on quite a few issues so I wanted to share. Good Luck.

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Marcia, Thank you so much for your report of your experiences. I value them because you are ketogenic, which is not yet very common. Since I posted my original question my blood glucose readings have dropped almost down to normal range, even first thing in the morning. For me, the key was eliminating frozen dinners. At 28 grams net carbs each, eating one to two a day was kicking me out of ketosis. Now I snack on very low carb protein bars (Quest brand) which satisfy my sweetness craving, and am avoiding carbs better.

The experiences you and others have reported do not support my theory that metformin was causing my high BGs. I think the more likely reason was my eating frozen dinners, which was preventing ketosis.

Thank you again. I applaud your getting off of your diabetes medications and attaining normal A1C readings. Ketosis really works.

Its those hidden carbs that you have to find and eliminate. While I don’t blame the Metformin, it was me and my eating habits, I do want to eliminate or reduce all my meds if I can. After a year of KETO I am happy and doing so much better.

Ketosis does work and it sounds like the frozen dinners discovery was your key! Good for you!!

Ketones in your blood will cause insulin resistance because it makes your blood ph more acidic.
I am type one, a few times I had my pump tubing come out and I didn’t know I started moving into DKA, which is not likely for a type 2 but still, when that happens I become insulin resistant. I need Tripple to quadruple the insulin to bring down my sugars for at least half a day.
They after a while it returns to normal.
If you are on a ketogenic diet, then you have higher levels of ketones and those levels stay high so it makes sense to me that your fasting numbers are higher.

Dear Timothy, You are correct that ketones make the blood acidic. However, insulin resistance involves much more than the blood, as it is an effect of the liver and the fatty tissues in the body.

Basically, diabetes types 1 and 2 are quite different, and most of the needed advice is different between the two.

A ketogenic diet is primarily useful for type 2. Its effects in type 1 have not been studied and I’m not even sure it is recommended in type 1. In type 1 your body cannot manufacture insulin, so you need it supplied externally, regardless of diet. You cannot survive without external insulin. Attempting a ketogenic diet in type 1 must be done carefully, if at all. I would never recommend it for type 1.

In type 2 diabetes, the body can still manufacture insulin, but not enough to cover the usual modern high-carbohydrate diet, which causes the body to be in permanent glycolysis, the metabolic state where the body is powered by glucose. Doctors consider glycolysis the only healthy state of metabolism. They are wrong.

For me, the management of my type 2 diabetes using medicines alone became a problem, since carbohydrate metabolism causes insulin resistance. This requires increasing medications over time until the body requires oodles of insulin pouring in to avoid the serious long-term effects of the disease, such as losing vision and feet. More insulin means more insulin resistance, so the situation gets worse over time and disaster becomes an increasing possibility.

A ketogenic diet, for type 2 diabetes, switches the body to a different state of metabolism in which fats are the source of power.

In this diet, which requires vitamin and other supplementation, insulin resistance does not occur, and any existing insulin resistance disappears as the liver and fatty tissues return to normal.

For me, my A1C measurements became normal over about a 4-month period of first being on a ketogenic diet, and have remained normal for years since without any diabetic medication other than one Metformin tablet a day which I only take to make my doctor happy, since he believes medication is necessary (it is not). My retinas and other potential neuropathies have remained in good health, instead of tissues continuing to show deterioration. My pancreas continues to put out enough insulin to cover me in ketosis, so I can exercise or not and remain healthy. This factor was important for me during isolation due to the current pandemic.

To summarize, a ketogenic diet can be expected to have very different effects in type 1 and type 2 diabetes, so it is important to remember that ketosis is NOT the same as ketoacidosis.