Plus other information I know due to having PCOS and taking met formin myself. :) I think I'm on 1000 just upped last july from 500.
From what I have heard, from a friend that does not have any imbalance hormonally but does have trouble conceiving, met formin will cause you to ovulate. Met formin is the generic for glucophage, which is a diabetic medicine. Its primary use helps you digest sugars more efficiently and can assist in weight loss, but be careful it can also assist in weight gain. Make sure you are eating a healthy diet while you are on it, or else it might have reverse affects. (cause sugars to drop too low, gain weight, stop ovulation due to dietary imbalance)
Metaformin is used to regulate hormones so your cycles are more consistant when you have PCOS.