Gonadotropin Releasing Hormone Antagonist (GnRH Antagonist) is a type of medication used to treat certain reproductive health conditions, such as endometriosis, uterine fibroids, and precocious puberty. It works by blocking the action of gonadotropin-releasing hormone (GnRH), a hormone that stimulates the release of other hormones involved in the reproductive cycle. By blocking GnRH, GnRH Antagonist can help reduce the symptoms of these conditions.