Can a naturally occurring hormone that promotes growth and development be a dieter's dream come true? The quest for an easier weight loss solution has some people taking human growth hormone (HGH) in pills, powders, and injections.
A few small studies have linked HGH injections with fat loss and muscle gain. But the changes seen were minimal -- just a few pounds -- while the risks and potential side effects are not. And experts warn that HGH is not approved by the Food and Drug Administration (FDA) for weight loss.
How HGH Works
HGH is produced by the pituitary gland to fuel growth and development in children. It also maintains some bodily functions, like tissue repair, muscle growth, brain function, energy, and metabolism, throughout life.
HGH production peaks during the teenage years and slowly declines with age. Studies have shown that obese adults have lower levels than normal-weight adults. And these lower levels of HGH have some people wondering whether a boost of HGH could enhance weight loss, especially in the obese.
HGH has also gained a reputation as a muscle builder, and its use is banned in the Olympics and other sports. However, there is little solid evidence that it can boost athletic performance.
Early Study Sparks Interest in HGH
Interest in using HGH for weight loss stems from a 1990 New England Journal of Medicine study that showed injections of synthetic HGH resulted in 8.8% gain in muscle mass and 14% loss in body fat without any change in diet or exercise. Although this study appeared to be promising, many later studies have shown no such benefit.
In March 2003, the New England Journal of Medicine took the unusual step of denouncing misuse of the 1990 study, pointing out that subsequent reports provide no reason to be optimistic.
Despite this, this 1990 study is still being used to promote Internet sales of HGH for weight loss.
Small Changes, But No Weight Loss
When adults with an HGH deficiency resulting from pituitary disease are given HGH replacement, it improves body composition -- increasing bone mass and muscle mass and decreasing fat stores.
But it does not cause weight loss in the obese, says Nicholas Tritos, MD, who co-authored an analysis evaluating the effectiveness of HGH for weight loss in obese people.
"Our results showed small improvements in body composition, a small reduction in body fat and increase in muscle mass, but on balance, weight did not change," he says. "More notable changes are seen when an individual is deficient in growth hormone from true pituitary disease."
Another study found that HGH therapy was linked to a small decrease in fat and increase in lean mass, but no change in body weight. The researchers concluded that HGH is not an effective treatment in obese people, and said more studies were needed.
Further, the American Association of Clinical Endocrinologists has warned that the use of HGH for obese patients is not recommended.
Pills and Powders: Risky and Expensive
HGH comes in injectable form, usually given once weekly, and is available only with a doctor’s prescription. HGH injections are approved to treat adults and children who have growth hormone deficiency, for people who are undergoing organ transplants, and for AIDS-related muscle wasting.
Companies marketing HGH pills and powders claim their products produce the same effects as the injected form. But Tritos warns that HGH is only effective when injected.
"HGH is a protein that will get broken down in the stomach unless it is injected," he says. "And besides, any drug not tested or approved by FDA is risky because it is unknown and not necessarily safe, pure, sterile, or what is being advertised."
The FDA has not approved HGH for weight loss for a variety of reasons, including the cost (about $1,000 per month), potential aggravation of insulin resistance and other side effects, and lack of long-term safety studies.
Healthy adults who take HGH put themselves at risk for joint and muscle pain, swelling in the arms and legs, carpel tunnel syndrome, and insulin resistance. In the elderly, these symptoms are more profound.
The Bottom Line
Using HGH for weight loss, muscle building, or anti-aging is experimental and controversial. HGH injections are believed to decrease fat storage and increase muscle growth to some extent, but studies have not shown this to be a safe or effective weight loss remedy.
Until more research can demonstrate the long-term safety and effectiveness of using HGH for weight loss, it's wise to avoid it.
Unfortunately, there are no magic bullets when it comes to losing weight. Healthy weight loss means taking in fewer calories than you burn in physical activity. Save your money for more fruits and vegetables, and a good pair of sneakers.
Kathleen Zelman, MPH, RD, is director of nutrition for WebMD. Her opinions and conclusions are her own.