I take the max dose of metformin for PCOS. The insulin resistance that goes with PCOS is the reason for the weight gain. Metformin deals with the insulin resistance. You don't have to be fully diabetic to be insulin resistant. When you get the IR treated, the testerone levels drop also, and other symptoms start to clear up. I was never a big eater and very active yet I still gained weight out of proportion to my eating. I have lost 20 pounds over the last six months after taking Metformin. Lots of other symptoms have started to clear up, too. There are other meds for PCOS besides Metformin, but it is used the most. There is a lot to PCOS and I have found a lot of information at [url="http://www.**********s.com."]www.**********s.com.[/url]