Uses: Leuprolide is used to treat advanced prostate cancer in men. It is not a cure. Most types of prostate cancer need the male hormone testosterone to grow and spread. Leuprolide works by reducing the amount of testosterone that the body makes. This helps slow or stop the growth of cancer cells and helps relieve symptoms such as painful/difficult urination. Talk to your doctor about the risks and benefits of treatment. Leuprolide is also used to stop early puberty (precocious puberty) in children. It helps to delay sexual development (e.g., growth of the breasts/testicles) and the start of menstrual periods. It also helps slow down the rate of early bone growth so that the chances for reaching normal adult height are increased. Leuprolide works by decreasing the amount of sex hormones that a child's body makes (estrogen in girls, testosterone in boys).