Human growth hormone
Human growth hormone (hGH; Somatotrophin) is a peptide hormone produced naturally by humans in the anterior pituitary galnd. The control of hGH release is primarily by the stimulatory effect of Growth Hormone Releasing Hormone (GHRH) and the inhibitory effect of somatostatin, both of which are secreted by the hypothalamus. The primary effect of hGH in humans is the promotion of bone and muscle growth. It also causes lipolysis (fat breakdown) and aids the body to utilise glucose for energy. As a result, in its synthetic form - recombinant human growth hormone (rhGH), or somatropin - it is an illegal steroid which some athletes abuse to increase their muscle mass and agility.