Oral contraceptive formulation having progestin / estrogen first phase and progestin second phase

摘要

This invention provides a method of contraception which comprises administering to a female of child bearing age for 28 days per menstrual cycle a combination of a progestin at a daily dosage equivalent to 30-150 mu g levornorgestrel and an estrogen at a daily dosage equivalent to 10-20 mu g ethinyl estradiol for 23-25 days beginning on day 1 of the menstrual cycle, followed by administering a progestin at a daily dosage equivalent to 10-100 mu g levornorgestrel for 3-5 days.