diabetes, type 2
"I was diagnosed in 2010 as "borderline" Type 2 and given Met 500mg dose 1 x day at breakfast. I was overweight and already being treated for Hypothyroidism with Levothyroxine sodium. after several months on it I started losing muscle strength and tiring easily, sleeping in afternoons, something I'd never done before. 
My husband was also on it 2 or 3x 800 mg per day,I don't remember now, but having been diagnosed years earlier in UK. he was ok on it, despite  also being on French equivalent of 
Warfarin, and something else, since his triple bypass op in 2008. So same drug doesn't always suit everyone, depending on other health factors. I ended up with a swollen spleen after taking Metformin, so took myself off it just B4 scan confirmed it!"