Triphasic oral contraceptive

摘要

A method of contraception in which an estrogen and desogestrel are administered daily in a three phase sequence for 21 days is disclosed. In the first phase a combination of an estrogen and a progestogen in a low but contraceptively effective daily dosage corresponding in estrogenic activity to 23-28 mug of 17alpha-ethinylestradiol and in progestogenic activity to 0.065-0.75 of norethindrone is administered for 5-8 days; followed by the administering of the same dosage of estrogen and a progestogen corresponding in progestogenic activity to 0.25-1.0 mg of norethindrone for 7-11 days; followed by the administering of the same dosage of estrogen and a progestogen corresponding in progestogenic activity to 0.35-2.0 mg of norethindrone for 3-7 days; followed by 4-8 days without administering either an estrogen or a progestogen, provided that the progestin dose should increase from the first phase to the second phase to the third phase, that the progestin is desogestrel at a dose in each phase of between of from 0.05-1.0 mg/day and that the dosage of estrogen is kept constant in each phase.