Human growth hormone
Touted as an anti-aging agent, athletes and others are taking human growth hormone to build up muscle and lose fat.
Human growth hormone (HGH) has several legitimate medical uses. It's a treatment for dwarfism in children and Turner's syndrome, a genetic disorder affecting girls that is caused by a missing or incomplete X chromosome. On an experimental basis, it's been used successfully to treat children who have been badly burned and AIDS patients with excessive abdominal fat.