Human Growth Hormone, "HGH" or simply "GH", is a naturally occurring hormone in the human body secreted by the pituitary gland. In youth, it is the hormone which is responsible for the growth of our bones, muscles and body. An certain amount of HGH is necessary for normal growth. If our bodies produce too little we become dwarfs, too much, we become giants. After age 21 our pituitary gland secretes less and less of this hormone, and by our 60's we only secrete amounts equal to what severely deficient persons in their twenties do, levels which usually require immediate medical intervention. Scientists say that our pituitary continues to have good amounts of HGH, but its secretion is inhibited by other chemicals.
In adults, instead of causing us to grow bigger, HGH is a chemical messenger for repair and maintenance. It keeps muscles from wasting, reduces accumulation of fat tissue, improves immune response, and keeps skin tissue smooth and elastic. In other words, it actually slows the physiological changes associated with aging. Many anti-aging scientists now believe that lowered HGH and other related hormones not only signify that we are getting older and starting to deteriorate, but they are the actual CAUSES of that aging and deterioration. This article will document that research and clarify some of the misinformation and hype now associated with HGH products on the market.
FDA ApprovedHuman growth hormone replacement has been approved by the FDA for decades for treating children who have growth hormone deficiencies. It has been very successful in reducing the incidence of dwarfism in the world. The main drawbacks to its use are the cost of the treatment (which is administered by injection twice a day and can run up to $1,000 per month), and some uncomfortable and potentially harmful side effects if too much is received. It is for these reasons that injectable HGH is not prescribed more commonly to older patients.
For years human growth hormone was only available from cadavers and was very expensive to extract and purify. Recently, however, it has been produced through recombinant genetic engineering, producing an extremely pure form of the identical molecule, so the costs are beginning to lower for the injectable HGH, but not as fast as one would expect.
HGH SupplementsIn the past twenty years, scientists have discovered that supplementing certain amino acids and other compounds can increase the body's release of its own endogenous HGH. These stimulators of GH production are often called "releasers" or "secretagogues." While not as potent as injectable HGH, they may be preferable for several reasons. First, the body has a "thermostat" which will usually self-regulate blood levels of the hormone, which is not possible with the injectible forms. Secondly, since we are not getting the raw hormone, there is no likelihood of suppressing our own endogenous production or even shutting it down permanently. Thirdly, taking the growth hormone boosters orally costs a fraction of the cost of the injectible form, usually $40 to $150 instead of $700-1000 per month. And lastly, the undesireable side effects of injectable HGH have not been documented with the oral releasers.
Forms other than the amino acid GH boosters are available, such as sublingual HGH sprays containing actual recombinant HGH at homeopathic (very small) levels, but there is some question as to the efficacy of most of them, and, I believe, little scientific basis for their being called "homeopathic," since taking HGH in high doses doesn't increase the symptoms as in traditional homeopathy. There are also questions about the HGH molecule's ability to remain stable in aqueous solution as well as its ability to pass through the oral mucosa, since it is such a large molecule. While there are anecdotal reports of the homeopathic sprays working for some, there are no studies published in respected journals on the NIH's PubMed site. There are now dozens of products jumping on the bandwagon now that word is getting out about the promise of HGH. My suggestion is that if you take a product for 3-4 months and don't notice a difference, try another brand before giving up on its use.
Oral estradiol hormone replacement in postmenopausal women has been shown to increase endogenous levels of HGH. LINK=> Shah, et al. J Clin Endocrinol Metab 2000 Aug;85(8):2649-59. This might account for the more youthful appearance and vitality of those on estrogen replacement therapy compared to their peers.
Most studies have shown that exercise is necessary for optimal growth hormone levels in adults, even in those getting GH injections or the releasers/secretagogues. Indeed, exercise itself increases the body's secretion of growth hormone. Those taking supplements should begin an exercise program as part of their anti-aging regimen to maximize results.
Research on Human Growth HormoneThe landmark study on HGH in aging adults was published in 1990 by Dr. Daniel Rudman at the University of Wisconsin and showed that a six month treatment of men in their 60's and 70's with injectable GH caused a visible loss of 10-20 years of aging in the participants. They increased lean muscle mass, lost fat, thickened their skin, increased bone mineral density, reduced plasma cholesterol levels, and felt more youthful. After the conclusion of the study, the participants gradually returned to their pre-treatment condition. LINK=> Rudman, et al., N Engl J Med 1990 Jul 5;323(1):1-6
Blackman's group, presented at the US endocrine meeting in San Diego in 1999, investigated the effects of Growth Hormone with or without testosterone supplements (in men) and estrogen supplements (in women). Their results also showed positive effects of GH on lean body mass, central fat, low-density lipoprotein cholesterol and aerobic capacity. In many instances there was a positive interaction between GH and hormone replacement with testosterone and estrogen, but it appeared that GH showed the most potent anabolic effects. (link not available)
Lowered blood IGF-1 (Insulin-like Growth Factor-1) levels (one of the accepted measures of HGH levels) were associated with elderly patients with more advanced cognitive deterioration. LINK=> Rollero A., et al: Neuropsychobiology 1998;38(2):73-9 This, along with nutritional deficiencies, may be risk factors in the development of senility and Alzheimer's disease in the elderly.
Growth hormone deficiency is related to reduced cardiac function in elderly subjects. LINK=> Colao, A., J Clin Endocrinol Metab 1999
While exercise generally increases GH levels, levels in middle aged men did not increase nearly as much as that of younger men. LINK=> Zaccaria M., et al: J Clin Endocrinol Metab 1999 Jul;84(7):2303-7
Oral arginine significantly increased GH levels by counteracting the inhibition of its release. LINK=> Gianotti L, et al. J Clin Endocrinol Metab 2000 Oct;85(10):3604-8
An amino acid solution of L-arginine hydrochloride, L-ornithine hydrochloride, L-leucine, L-isoleucine, L-valine increased pituitary responsiveness and GH levels in athletes. LINK=> di Luigi L, et al: Med Sci Sports Exerc 1999 Dec;31(12):1748-54
CautionsWhile injectable HGH prescribed under medical supervision is generally safe, its use in adults to prevent aging is still considered experimental, an "off-label" use of the product. The older one is, the more he/she seems to benefit from HGH, although there is anecdotal evidence that athletes may enhance their performance by taking HGH (the injectable form is illegal in FINA competition, but difficult to test). The only caveats are that it should not be taken by pregnant or lactating women, dosage of the injectable should be monitored closely for adverse side effects and, hypothetically, those with diagnosed cancer, both injectable and the releasers. (While there is no evidence that HGH increases one's risk of getting cancer, there is some controversy regarding its effect on existing cancers. It would be prudent to await the results of long term studies.)
Because the growth hormone releasers are simple stacked amino acids that protein is broken down into with normal digestion, there appears to be less risk of side effects than with the injectable form. With them it is virtually impossible to get too much GH, since the body will self regulate its release. Regarding risks of taking HGH, one must remember the well-documented risks of NOT taking it - senility, frailty, lack of energy, obesity, poor quality sleep and general deterioration of physiological functions. Most assuredly, any new side effects that might show up in the future will pale in comparison.
ConclusionHuman Growth Hormone appears to be the closest we've come to discovering the legendary "Fountain of Youth". While more study is needed (and being done), it is, along with antioxidant vitamins and minerals and exercise the ONLY way science has actually been able to turn back the clock for the elderly. The results many of the elderly persons taking both the hormone and the releasers get are nothing short of miraculous - a renewed vigor for life and better health. Many have reported their grey hair returning to its normal color. Of course, if one's in poor health, it's quite difficult to be a vigorous person. Perhaps increasing our growth hormone levels will keep us healthy until we reach the century mark and beyond.