Gonadotropins are used during fertility treatments such as intrauterine insemination (IUI) or in vitro fertilization (IVF). These fertility medications are given by injection that contain follicle-stimulating hormone (FSH) alone or combined with luteinizing hormone (LH). During a regularly occurring menstrual cycle, both FSH and LH are produced by the pituitary gland in the brain to naturally stimulate the ovaries to make a single egg each month. When FSH and/or LH are given as an injection as fertility treatment, they work directly on the ovaries to make multiple follicles which are cysts containing the eggs.