Metformin, PCOS, and INSOMNIA!!!!?

It is unlikely to be the metformin, but your body is reacting to the glucose being used in your body properly. I have Pcos and just have found out I am pregnant, I have been on metformin for three months and I have only just stopped being able to sleep well. Most women with Pcos have energy level problems because of the insulin resistance (which is why you take metformin) and the fact your muscles don't burn the glucose properly because it doesn't get there well enough. So it leaves you tired and cranky (I know this one well) but when I am taking the metformin I have energy and I use it and actually sleep better because my body is working more efficiently. It may be a side effect for you, but more probably to do with excess energy not used during the day because of taking the metformin.