Diabetes, Type 2
"I take 500 mg twice daily.  Initial gastric symptoms passed quickly.  No help in weight loss.  Some help in lowering blood sugar.  Main side effect is extreme tiredness and fatigue.  Never feel like exercising.  Stopped taking metformin a few times due to fatigue, but when sugar levels escalated to higher than before starting it, I got back on it and just put up with the tiredness. "