Human Growth Hormone (HGH) is a naturally occurring hormone that is essential to human growth and the development of bodily structures. Some people produce an abnormal amount of HGH and this can cause conditions such as gigantism and acromegaly caused by overgrowth of certain tissues. Children with gigantism can grow exceptionally tall -- in rare cases over 7 and even 8 feet tall.
HGH is used medically to stimulate growth in people who lack this hormone, or in some cases to help those recovering from serious illness.
HGH in Bodybuilders, Athletes, Rejuvenation
Because of a perceived advantage to muscle growth and strength, bodybuilders and athletes who are tempted to take performance-enhancing drugs and supplements like steroids have taken HGH in order to gain athletic advantage, or for rapid, cosmetic muscle growth. Because HGH taken orally can be broken down by digestion, HGH is injected when used as a supplement drug.
HGH is also promoted as an agent for rejuvenation for aging people who want to look and perform younger.
Side Effects of HGH
The following side-effects of injected HGH have been reported:
- muscle or joint pain
- suppression of pituitary/hypothalmus gland function
- swelling of body tissues (edema)
- carpal tunnel syndrome (wrist nerve pain)
- elevated blood glucose levels.
Position Stand of the National Strength and Conditioning Association
The NSCA in its 2009 review, concluded this about HGH:
"Human growth hormone increases lean body mass within weeks of administration; however, the majority of the change is within the water compartment and not in body cell mass. Human growth hormone is unlikely to be administered as a single agent but often in combination with androgens. Combined administration of hGH and resistance exercise training is associated with minimal gains in lean body mass, muscle size, and maximal voluntary strength in men compared with resistance exercise alone."Another reviewer (Liu) said this:
"Claims regarding the performance-enhancing properties of growth hormone are premature and are not supported by our review of the literature. The limited published data evaluating the effects of growth hormone on athletic performance suggest that although growth hormone increases lean body mass in the short term, it does not appear to improve strength and may worsen exercise capacity. In addition, growth hormone in the healthy young is frequently associated with adverse events."
1. Only one consistently positive effect of HGH use is highlighted in recent studies, and that is the enhancement of lean body mass, in other words, fat loss. This works because HGH promotes enzymes called lipases that break fat down and providing preferential burning of fat.
2. For the bodybuilder or athlete looking for strength advantage, HGH has little to offer used alone, although it may promote growth of collagen tissues like tendon, ligament and bone. It seems that strength fibers (myofibrills) are not enhanced, but sarcoplasmic hypertrophy (muscle swelling due to fluid retention) is the main beneficiary. Adverse effects can be significant.
3. HGH does not appear to improve athletic performance significantly in a range of studies and provides minimal strength advantage. A few single studies have shown some increase in sprint performance in amateur athletes. Edema (swelling of tissue) may be a limiting factor.
4. Human Growth Hormone is banned in most countries under the World Anti-Doping Authority (WADA) protocols.
Hoffman JR, Kraemer WJ, Bhasin S, et al. Position stand on androgen and human growth hormone use. J Strength Cond Res. 2009 Aug;23(5 Suppl):S1-S59.
Liu, H, Bravata, DM, Okin, I, et al. Systematic review: The effects of growth hormone on athletic performance. Ann Intern Med 148: 747–758, 2008.