There are loads of possible side effects other than a bad stomach with Metformin.I was told i had type 2 diabetes in 2015.Although i had it for 6 years without tellin me about it.Anyway the doctor sent me away with a prescription for Metformin. I went to Boots the chemist in york.The pharmacist told me that you will have a gippy stomach for 2 weeks after taking them.I thought i'm not taking that ****.I felt fine at the time.Later that month i went to the Philipinnes for 8 months.I started getting hot aches and stabbing pains in my legs below the knees in bed at night.,so i bought some Metformin .at the the local pharmacy[you can buy most medications over the counter without a prescription].I read the information leaflet There was a list of possible side effects as long as your arm.some sounding quite serious.then at the bottom of the leaflet,it said this medicine will not prevent complications.I started taking 2 tablets a day. about 2 weeks later i notice that the right hand side of my right leg went weak .I could not climb up the slightest step ,there was no strength there.In fact we were in town crossing the road ,i tried to step up onto the footpath.there was no strength there.I was about to fall backwards into the the road .My girl friend grabbed me stopping me falling into the path of an approaching jepney she certainly saved me from serious injury or death.The back of my left leg went weak.A few week later, i started getting severe back pains on th the right hand side.I stopped taking the Metformin.Within 24 hours the pain went completely. but i was still left with a duff right leg .i had to climb steps and stairs one legged with my left leg which i have arthritis in the hip.what a state.It did not end there.I developed a collapsing right knee.It would buckle without warning' i lost count of how many time i ended up on the deck.all becanse of metformin.It has now cleared up .when i got back to the UK.September last year my legs were that weak I had to to get a taxi back home from Manchester airport to York .very expensive.I was frightend to go out of the house,for fear of falling.Thing have improved a bit 6 months ago i went on a 24 hour fasting diet .I lost 3st in weight reduced my blood sugar fasting readings from between 10.8 mml/l and 16mml/l to between 4.0 mml/l to 5.8 mml/l.I have totally reversed my diabetes.i can now eat what i like without adverse effects i have got feeling back in my feet and toes my leg ulcers have healed up no more hot sweats or going dizzy when out and about no more peeing 13 or 14 times in the night.no more falling asleep all the time .I feel very much better i have got my feeling of well being back.Metformin may be ok for some people ,but certainly not for me.