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Human Growth Hormone And The Search For The Fountain Of Youth
Last reviewed by the Faculty of the Harvard Medical School on December 3, 2009
By Harold J. DeMonaco, M.S.
Massachusetts General Hospital
"Do you want to look and feel 10 years younger?"
I've heard this question on the occasions I find myself watching infomercials very late at night. If you have not had the opportunity to view these, you have missed out on some wonderful television. Aging movie stars, athletes and just plain folks provide entertaining, if not educational, testimonials on a host of products.
Not surprisingly, many infomercials are for products that promise to help you lose weight, stay fit and generally keep or regain youthful vigor. Among these products are those containing human growth hormone, or products that claim to stimulate the production of human growth hormone in the body.
Human growth hormone, or HGH, is secreted by the pituitary gland. Human growth hormone in combination with other hormones such as IGF-1 (insulin growth factor-1) is responsible for body development early in life. Children deficient in growth hormone do not grow to their full potential height and have short stature. The original use of synthetic human growth hormone was as a replacement in these children, allowing them to grow taller.
The interest in growth hormone has shifted dramatically in recent years. Growth hormone is now touted as the fountain of youth. As we age the amount of growth hormone secreted declines. By age 55, blood levels of growth hormone decrease by about one-third compared to people ages 18 to 35. This drop in growth hormone occurs at just about the same time and rate as the reduction in muscle mass and an increase in fat, so it is easy to see why people have thought about a link between growth hormone and aging.
Based on medical research done with human-growth-hormone injection, we know that elderly men and women can improve strength, increase their muscle mass and decrease the amount of fat in their bodies, at least when HGH is given for several months. It is important to know that the medical experiments with human growth hormone have been done under close medical supervision and only with an injectable form of the drug. We do not know what happens to long-term use of human growth hormone in adults. Like all drugs, human growth hormone does have side effects.
Does human growth hormone make you feel and look 10 years younger as some would suggest? As this moment, we know that if you give healthy adults growth hormone they will increase the amount of muscle and reduce the amount of fat in their bodies by about 5% to 7%. Strength improves in some muscle groups but not in all.
However, we know that there is a downside. Fluid buildup is seen in almost half of adults treated with human growth hormone. About 25% of adults will have nausea and vomiting early during treatment. Some people have developed a painful nerve condition in the hands called carpal tunnel syndrome during treatment with human growth hormone. Real human growth hormone has to be given by daily injection.
The commercials are sometimes correct in their statements about the benefits of human growth hormone. But, real growth hormone is a prescription drug and it cannot be obtained legally without a doctors approval. Human growth hormone is not absorbed when taken by mouth, so tablets cannot work. Tablets and sprays designed to be placed under the tongue wont work either.
And what about those products that claim to increase your own production of growth hormone? Most contain a unique mixture of amino acids (the building blocks of protein and muscle). Some contain herbal products that are said to increase the amount of testosterone, increase energy, improve mental abilities and increase vitality. Because none of the products has been studied, it is not known if they have any value. Except, that is, to the people who sell them. Most of the products are very expensive.
Although growth hormone does increase muscle and decrease fat, we dont know enough about using it for long periods of time to recommend it. The products that are sold that either contain human growth hormone or are said to stimulate growth-hormone secretion are expensive, and there is no evidence that they work.
Harold J. DeMonaco, M.S. is senior clinical associate in the Decision Support and Quality Management Unit at the Massachusetts General Hospital and is currently a Visiting Scholar at the MIT Sloan School of Management. He is author of over 20 publications in the pharmacy and medical literature and routinely reviews manuscript submissions for eight medical journals.