Metformin is a drug used to regulate insulin levels in women with PCOS. The reason being is that insulin resistance (Web Def: n. State in which the body does not respond to the action of insulin hormone although enough insulin is produced.) is often the cause of infertility in women with PCOS.

Its also used by Type 2 Diabetics for the same reason, to regulate insulin which will also regulate blood sugar levels.

They were able to find out my insulin levels by doing a fasting glucose test, and thats why I have only just been prescribed this medication. My Dr also told me that one of the reasons women with PCOS stay on metformin (not just when trying to concieve) is to reduce the risk of Diabetes later in life.

If anyone wishes to elaborate feel free.

HTH's

*hugs*
Cailin