Is there any proof that Metformin works long term? I have read in study of 13000 people worldwide it had minimal effect on long-term onditions such as amputation and eye failure between those who took it and those who didn't. I have taken it on docs orders for 4 years and it has ruined my digestive system (never leave loo paper at home, never pass a toilet- you get the drift). It has dominated my life. Stopped taking it as part of blood sugar diet a month ago. Now no problems on the toilet front at all. Blood sugars between 4.4 and 7.4. So,what is my gain for taking it? Any other stories or comments welcome. Ps: I'm 55 and otherwise fit.