Human growth hormone (HGH) is secreted by the pituitary gland, with peak production occurring during adolescence. This complex hormone regulates a multitude of functions throughout the body, some of them still undiscovered. Primarily an anabolic, or building, hormone, its main role is regulating growth and cellular regeneration. The quantity of HGH secreted naturally declines with age, while diet, activity level, stress and gender may also affect amounts secreted. Human growth hormone replacement therapy might be advised if HGH levels are significantly below normal, and adverse effects from this deficiency are apparent.
Although popularly promoted as an almost miraculous anti-aging therapy, in many regions of the world HGH is not approved for this use. The primary medical use of human growth hormone replacement therapy is for children with severe growth deficiencies. In order to increase hormone levels, an injectable form of the hormone is given to children suffering from Turner’s syndrome, Prader-Willi syndrome or other disorders that cause a deficiency of human growth hormone. By increasing the amount of HGH, the child’s growth approaches normal. The hormone’s functions in bone growth and skeletal muscle growth affect the stature of the developing child.
Approved uses in adults include countering the effects of wasting in acquired immune deficiency syndrome (AIDS) patients and for patients with acquired growth hormone deficiency. This disorder generally results from damage to the pituitary gland, interfering with its ability to secrete HGH. For patients with acquired growth hormone deficiency, human growth hormone replacement therapy increases muscle mass and strength, bone density and improves cardiac functioning. One of the most noticeable changes in adults using HGH therapy is the change in body composition from fatty to lean.
Side effects and risks are lowest for children receiving human growth hormone replacement therapy. There may be injection site swelling and minor pain, as the hormone is only available as an injection. Adults, on the other hand, have experienced fluid retention with resulting hypertension, joint pain, and an increased risk for developing insulin resistance and diabetes. Experimental uses of human growth hormone replacement therapy are being studied for a variety of debilitating conditions including heart failure, cystic fibrosis, Crohn’s disease and obesity.
The human growth hormone used in HGH therapy is a recombinant form produced in the laboratory. It is chemically identical to the natural form of the hormone. The therapy is very expensive, and approved uses often do not include anti-aging therapy. As an alternative, anti-aging treatments are being developed using substances that are thought to promote the body’s own production of HGH. These are generally available without a prescription, are significantly less expensive, and are taken orally.
In addition to its unapproved anti-aging use, body builders and athletes have used HGH therapy illegally to enhance performance. For decades, there was no reliable test that could distinguish natural HGH from synthetic HGH, and use among athletes was widely reported. New tests are under development that can differentiate between the two. Athletic use of HGH is banned by many sporting associations, and tests are inconclusive about its benefits in increasing performance.