HCG stands for Human Chorionic Gonadotropin. It is a polypeptide hormone made in both women and men. HCG stimulates the natural testosterone creation system of men and is thus viewed as a viable option to the standard Testosterone Replacement Therapy. Many bodybuilders run HCG to keep their natural testosterone production functioning while on a cycle. The Pregnyl HCG comes with 1ml of Sterile Water and 5000iu HCG powder.