Wow, after reading everyone's side effects I don't feel so alone. I've been taking Metformin HCL 1000 mg/day for a few weeks now for PCOS. First it was the severe diarrhea, which has sort of subsided. However, my other symptoms have been getting worse. Such as: extreme fatigue for no reason, weird sweating like on my palms and chest, and severe thirst/frequent urination. I wake up at least 3 times a night to pee, but then I'm so incredibly thirsty I could drink a gallon of juice or water, but then of course I have to pee again. It's a never-ending cycle and I just want to know, do these symptoms go away after awhile? If not, I really don't want to take this anymore. I'm also bipolar and it's been affecting my moods making me very irritable and depressed.