Prostate cancer drug. Boxes of Zoladex used for treating prostate cancer. Each box contains a single-use syringe containing the drug goserelin acetate. The prostate is a gland beneath the bladder in men. Goserelin is an analogue of the body chemical luteinising hormone-releasing hormone (LH-RH). Goserelin causes reduced amounts of LH to be released from the pituitary gland, which effectively castrates the patient. Prostate tumours typically respond to male sex hormones (androgens), and goserelin thus starves the tumour. LH-RH analogues are usually taken with an anti-androgen drug to prevent growth of the tumour during the initial stages of the treatment.