Histrelin is a man-made form of a hormone that regulates many processes in the body. Histrelin overstimulates the body's own production of certain hormones, which causes that production to shut down temporarily. The Supprelin LA brand of histrelin is used to treat precocious puberty in both male and female children. The Vantas brand of histrelin is used to treat symptoms of prostate cancer in men. Vantas should not be used in women or children. Histrelin treats only the symptoms of prostate cancer but does not treat the cancer itself. Use any other medications your doctor has prescribed to best treat your condition. Histrelin may also be used for purposes not listed in this medication guide.