Growth Hormone Prompts Growing Concern
Alleged Anti-Aging Agent May Work, But More Often Backfires
WebMD News Archive
Last November, one of the largest studies published suggested that injected HGH did build muscle and bone mass and help healthy seniors lose weight. However, 40% of the 131 men and women studied developed serious side effects -- including arthritis-like joint pain and swelling, carpal tunnel syndrome, and diabetes-like changes in blood glucose levels. These side effects stopped after the study participants stopped taking the hormones, says that trial's lead researcher.
"While they did have an increase in muscle mass, there was no increase in muscle strength or exercise endurance," says Marc R. Blackman, MD, scientific director for clinical research at the National Center for Complementary Medicine, a branch of the National Institutes of Health. "The improvements they experienced were not functionally relevant."
Blackman, a leading researcher in this area for 25 years who has personally conducted several studies, says, "While the use of injected growth hormone is exciting, they are not ready for prime time." He, too, is especially concerned about the use of amino acid pills, which are sold on various anti-aging web sites and through magazines. These amino acid pills are marketed as having the potential to increase the body's own growth hormone levels.
"I have been imbedded in this research for a long time, and there are no controlled studies that I know of to support any of the claims made on the use of these pills," he tells WebMD. "The claims are ridiculous, because growth hormones taken by mouth are degraded by enzymes in stomach. But they can be dangerous for many other reasons."
Besides increasing risk of liver damage, these products could interfere with other medications, such as the blood-thinner Coumadin. "They can either exacerbate its effect and cause a bleeding tendency, or lessen its effects and the benefits of preventing clotting could be reduced," says Blackman. "Since these pills haven't been well tested, we really don't know their long-term effects."
While proponents of these products cite numerous studies of their safety, Blackman says these trials typically last only for a few days or weeks and involve few participants. And they have not "tested" these pills against placebos, says Blackman -- the gold-standard method of clinical study.
Even plastic surgeons are now advising their colleagues against administering HGH products, which allegedly reduce wrinkles and improve skin health. In the January issue of the medical journal Plastic and Reconstructive Surgery, surgeon W. Glenn Lyle, MD, chair of the Plastic Surgery Educational Foundation, published an article critical of these products.
"Plastic surgeons are often called upon to do things to make patients look better, but these products' use is unproven and there are potential dangerous side effects that have been proven," Lyle tells WebMD. "Plastic surgeons that are administering these products are doing it outside the bounds of what they were trained to do."