Don't bet against it. Human growth hormone is secreted by the pituitary, a tiny gland located at the base of the brain, not far from the pineal. Human growth hormone has many vital functions, rang-ing from building bones and muscles to strengthening the immune system and helping to heal wounds. Dwarfism is a consequence of lack of hGH, and abnormally small children are treated with it to help them to grow closer to normal size. While growth hormone is secreted in large amounts by adolescents during sleep, in adulthood its production diminishes, often as much as ten to 15 percent every ten years in men.
Women maintain higher levels until they reach menopause, then their hGH production rapidly declines.
Resear-chers have not missed this obvious hint that slowdown in hGH may be related to aging. Low levels of hGH are associated with loss of muscle leanness and accumulation of fat. Worse, as the individu-al's weight increases, hGH levels drop more, setting up a negative feedback loop. Injection of hGH improves muscle strength and leanness, apparently helping the body to build protein instead of fat. Dr. Daniel Rudman of the Medical College of Wisconsin tested hGH's anti-aging possibilities with a group of male volunteers in their 60s and 70s.