How long should it take for metformin to make the menstrual cycle run?

Not designed 4 that: Metformin is often prescribed for women with polycystic ovarian disease to aid their fertility potential. It is not an ovarian stimulating drug; it is designed to improve carbohydrate (cho) metabolism. For some, improved cho metabolism will increase the likelihood of "kick-starting" cycles... Give it 3 months or so, but if you want to get pregnant, an ovarian stimulator like Clomiphene is best.