Human growth hormone (HGH) is made by the pituitary gland. It is essential for normal growth in children and maintenance of organs and tissues as we develop. Kids of abnormally short stature who are diagnosed with growth hormone deficiency can be treated with daily shots of synthetic HGH, which usually enables them to reach a normal adult height. HGH may also be recommended to adults who have developed pituitary deficiency due to various causes.
Beyond that, I know of no legitimate use for HGH. I definitely do not recommend the anti-aging supplements being promoted on the Internet and elsewhere as HGH or HGH releasers. (Real HGH is a prescription drug costing about $20,000 per year. HGH "releasers" are in development, but none is currently available.) HGH does decline with age, but there is no evidence to suggest that injections of growth hormone in otherwise healthy adults will extend life or improve general health. Some studies show that supplemental HGH does increase muscle mass, but there's a question of whether it significantly improves muscle strength or function. A Stanford University review of clinical studies concluded that the only benefit of taking HGH was a slight increase in muscle mass. The researchers found that risks included significantly more soft tissue swelling and joint pain and carpal tunnel syndrome among the approximately 500 people who participated in 31 studies the researchers analyzed. The data also suggested an increased risk of diabetes and prediabetes although the association didn't reach statistical significance. The review was published in the January 16, 2007, Annals of Internal Medicine.
I discussed HGH with Randy Horwitz, M.D., Ph.D., medical director of the Arizona Center for Integrative Medicine here at the University of Arizona. He noted that daily HGH injections are expensive and don't mimic the normal secretion patterns of the hormone. Dr. Horwitz also warned that there are serious risks associated with using HGH as an anti-aging strategy – joint pain, high blood pressure and even diabetes have been associated with HGH administration and, possibly, an increased risk of prostate cancer. What's more, no studies have looked at the long-term effects of HGH in older adults.
You also should know that claims for so-called HGH "releasers" said to prompt the body to trigger release of HGH by the pituitary are unsubstantiated. I know of no studies demonstrating that they work as advertised. The only way to get supplemental HGH into the body is with regular, sometimes daily, injections, available only by prescription. Unless you have a legitimate medical need for supplemental HGH, it could do you more harm than good. If your goal is healthy aging, focus on your diet and regular physical and mental exercise. There is no hormonal fountain of youth to replace positive effort.
Andrew Weil, M.D.