A method of contraception in a female is provided. The method includes administering to the female daily for a first number of successive days an oral combination drug formulation of a progestin and an estrogen. The oral combination drug formulation is administered in a multiphasic dosing regimen comprising a second number of phases with duration of each phase is a third number of days. The doses of each of the progestin and estrogen in each subsequent phase of the regimen increase by a predefined dose increment as compared to the corresponding doses of the progestin and estrogen administered during immediately preceding phase of the regimen. The ratio of a daily dose of progestin to a daily dose of estrogen is maintained at a constant level during the entire dosing period. The first number of successive days period is followed by a fourth number of days without progestin and estrogen administration.
