A method of female contraception which is characterized by a reduced incidence of breakthrough bleeding after the first cycle which comprises monophasicly administering a combination of estrogen and progestin for 23-25 consecutive days of a 28 day cycle in which the daily amounts of estrogen and progestin are equivalent to about 1-35 mcg of ethinyl estradiol and about 0.025 to 10 mg of norethindrone acetate, respectively, and in which the weight ratio of estrogen to progestin is at least 1:45 calculated as ethinyl estradiol to norethindrone acetate. view more

The method of claim 1 in which the daily amount of progestin is equivalent to 0.5-1.5 mg of norethindrone acetate.

The method of claim 1 in which the weight ratio is at least 1:50.

The method of claim 1 in which the combination is administered for 24 days of the 28 day cycle.

The method of claim 1 in which the estrogen is ethinyl estradiol.

The method of claim 1 in which the progestin is norethindrone acetate.

The method of claim 1 in which the daily amount of estrogen is up to 30 mcg of ethinyl estradiol.