The substance cyproterone acetate contained in this medicine blocks the effect of endogenously produced and exogenously administered androgens at the target organs by means of competitive inhibition. The stimulating effect of male sex hormones on androgen-dependent structures and functions is weakened or abolished by cyproterone acetate. Excessive sebaceous gland function is decreased. Apart from the described anti-androgen effect, cyproterone acetate also has a progestational action. The ethinylestradiol in the combination inhibits ovulation and changes the cervical mucus and the endometrium rendering them unfavourable for sperm penetration and nidation of a fertilised ovum, respectively.