I have been on Metformin for 6 days (still only 1 tablet)
I have read several different views about Metformin and I can only say that we react differently because we are different. It would seem that one is started on a low dose because of the side effects, the intention would be to increase the dose in the hope that your tolerance would improve with time. I have read on this forum that Metformin doesn't have much effect until one is taking as much as 4 X 500mg per day, the dose I was on.
I have had many problems over the last 20 years, when I refused to take it in 2002, the drug I was then given had an even worse effect on my health and life, even affecting my liver function, which was why I was taken off Rosiglitazone (now withdrawn). I recently stopped again because of the dreadful diarrhea, which isn't compatible with plane journeys and being in foreign parts. I'm using my FS Libre and the one difference I've noted is that so long as I avoid carbs completely I can keep my BG to normal levels, as soon as I cheat with just one slice of bread or a sprinkle of crystallized ginger in my yoghurt, my BG goes mental and can take several hours to come down again.
One interesting thing is that my insulin resistance is less now (having stopped Metformin) than it was last January (private blood tests) which may be down to my attempts at a very low calorie diet, similar to Newcastle, obviously somewhat successful.
I can't suggest anything, I've obviously persevered over the years, but there comes a point when it's intolerable and we have to decided ourselves what to do.
