A class of medications used to enhance fertility, usually by stimulating follicle growth. These drugs include: HMG Human Menopausal Gonadotropins (Pergonal, Repronex) Equal parts of the naturally occurring hormones FSH and LH. Used for ovarian stimulation and multiple follicular development prior to IVF treatment. FSH Follicle Stimulating Hormones (Follistim, Gonal-F, Bravelle) Has essentially the same function as the HMGs. They are used for ovarian stimulation and multi-follicular development. They contain FSH only and virtually no LH. HCG Human Chorionic Gonadotropin (Novarel, Pregnyl, Ovidrel) Sometimes called the "pregnancy hormone" as this is the hormone detected by home pregnancy tests. In the manufactured form it is used to cause ovulation in insemination cycles and is given for final maturation of oocytes (eggs) prior to IVF. GnRH Gonadotropin Releasing Hormone (Antagon, Cetrotide, Lupron) Used in fertility treatment to prevent premature ovulation during ovarian stimulation prior to IVF.