How old are you? Stats? I have also read a lot from others posting that after long periods of use significant weight gain is achieved (not warranted). Now these postings are from individuals who have diabetes, PCOD, ect.... and are usually on other medications and taking doses of 1000 mg twice a day. Most have also reported severe diarrhea, nausea, dizziness, and painful bloating. Now they claim they have been on the same diet when this occurs as when they were loosing weight, but most of them are a bit fallacious, lets face it all of us perceive our selves as eating good but in reality were not. Wanting and doing one thing are completely different. Until a scientific study comes out stating, Metformin will help with weight gain with no or limited side effects, I would suggest to stay away. When it comes to insulin or anything that effects insulin properties, one needs to be very experienced and well versed on the subject and then it should be a last resort.