30-60 days. This medication has a half life of 26 hours. It takes about 5 half lives to clear it from your system; so that's about 5 days for it to stop inhibiting the actions of the pituitary gland in the brain. This medication surpresses ovulation by inhibiting FSH and lh hormones which are made by the pituitary. There is variation in each patient regarding the pituitary returning to normal functionality.