Zoladex (generic: goserelin) is a prescription hormonal implant used to treat prostate cancer and breast cancer. It is also used for other conditions unrelated to cancer such as endometriosis and abnormal bleeding of the uterus. Zoladex implant is in a class of medications called gonadotropin-releasing hormone (GnRH) agonists. It works by decreasing testosterone production in men and estrogen production in women.

This medication comes in the form of an implant that is inserted just under the skin of the stomach every 4 weeks. Some people will receive an injection once every 12 weeks.

Common side effects of Zoladex include hot flashes, sexual dysfunction, and headaches.