Controlled ovarian stimulation for in-vitro fertilization treatment using preparations that contain follicle-stimulating hormone has been routinely performed since the 1980s. The early preparations were urinary human menopausal gonadotrophins, containing follicle-stimulating hormone and luteinizing hormone. In the early 1990s, highly purified follicle-stimulating hormone preparations were introduced because of a desire to provide drugs for subcutaneous administration with a lower risk of allergic reactions. Intensive research resulted in the discovery of recombinant follicle-stimulating hormone, which is more potent that the highly purified follicle-stimulating hormone, resulting in significantly higher clinical pregnancy rates. The two recombinant follicle-stimulating hormone preparations available appear to be equally effective and provide comparable results. Gonadotrophin-releasing hormone antagonists, which have recently been introduced, appear to be effective in preventing a premature rise in luteinizing hormone during ovarian stimulation for in-vitro fertilization, as well as improved response to lower doses of gonadotrophins. It is envisaged that the availability of recombinant gonadotrophins and gonadotrophin-releasing hormone antagonists will ultimately lead to shorter, cheaper and safer treatments, using reduced dosages.