A drug used to treat advanced prostate cancer. Under the brand name Lupron, it is also used to treat early puberty in children and certain gynecologic conditions. Eligard is also being studied in the treatment of other types of cancer. It blocks the testicles from making testosterone (a male hormone) and the ovaries from making estrogen and progesterone (female hormones). It may stop the growth of prostate cancer cells that need testosterone to grow. Eligard is a type of gonadotropin-releasing hormone (GnRH) agonist. Also called leuprolide acetate, Lupron, and Viadur.