Abstract
A hypersexual pedophiliac sex offender was treated with the antiandrogen medroxyprogesterone acetate for 500 days. During the treatment, his testosterone blood levels significantly decreased, nearly to female values. Pituitary gonadotropin and urinary steroid metabolite levels diminished initially. Medroxyprogesterone therapy resulted in decreased libido, few side effects, and no recurrence of sex offenses, but there was no change in the patient's sexual orientation.