The invention relates to a method of hormonal female controlled “on demand” contraception, in which a pharmaceutical preparation comprising a COX inhibitor and levonorgestrel is taken on demand prior to expected sexual intercourse. Further subjects of the invention relate to pharmaceutical compositions and application regimes for “on demand” contraception.本發明係關於一種激素女性控制之「依需求(on demand)」避孕的方法,其中在預期性行為前依需求服用包含COX抑制劑及左炔諾孕酮(levonorgestrel)之醫藥製劑。本發明之其他標的係關於用於「依需求」避孕之醫藥組合物及應用療法。