Last week, when Roger Clemens told a congressional committee that it was his wife, not he, who had used human growth hormone, the embattled baseball star touched on a great big nonsecret about the alleged wonder drug: professional athletes seeking a competitive edge aren't the only ones who have turned to the controversial substance, which has been banned by all major-league sports in the United States as a performance-enhancing substance. High-school athletes, fading movie stars, aging prom queens and just plain, vain folks around the world spend an estimated $2 billion on the stuff every year. As many as 30,000 Americans are believed to have tried human growth hormone (HGH).
But while tales of stronger, faster and younger-looking customers abound—thank you, Internet marketers—the science behind HGH remains mired in contradictory and inconclusive results. In the two decades since scientists figured out how to mass-produce it, the myth of HGH's power has continued to grow, far exceeding what is supported by research into the actual effects of the substance. Proponents and opponents alike appear to have oversold it. "The biggest problem is that you have something that people believe works," says Richard Hellman, president of the American Association of Clinical Endocrinologists. "And when they believe it works, they will use it, no matter what the studies show."
What the studies show, in fact, is that HGH benefits a relative few, including the elderly, some AIDS and tuberculosis patients, and people whose natural production of the hormone is severely diminished, either from a pituitary tumor or a birth defect. Noticeably absent from the list: future Hall of Famers, Olympians and other athletic superstars.
Natural HGH is manufactured by the pituitary gland, a structure about the size of a small grape located at the base of the brain. Its main job is to stimulate the production of bone, muscle and cartilage in growing children. Hence, the hormone is most active during childhood and adolescence when the body is still developing. After the age of 20, however, HGH production starts to drop off, and continues falling throughout adulthood into old age.
In the early 1980s, scientists found that giving supplemental HGH to men in their 60s and 70s could increase muscle mass and skin elasticity while reducing body fat and minimizing bone loss. Excited by their findings, some study authors eagerly trumpeted this use of HGH as akin to turning back the clock 10 to 20 years. Women and men of all ages embraced the drug as an injectable fountain of youth. (Online buyers beware: HGH in pill form is destroyed by acid in the stomach and has no effect.) But, experts say, their enthusiasm has been based on a faulty premise. Yes, the body's own production of HGH slows to a crawl by the age of 60. But before then, at 30 or 40, for example, the body is still making plenty of its own. So, while giving supplemental HGH to someone in his 60s might help, giving it to a younger person probably won't.
But that hasn't stopped a lot of young athletes from using HGH in the hope of improving their performance, or, like pitcher Andy Pettitte, speeding their recovery from an injury. Even some sports doctors have given anecdotal testament to the drug's healing power, claiming that it can cut recovery times—from wear and tear, surgery and sports injuries—in half. "Our observations tell us that it works and that it works well," says Dr. Richard Hawkins, former team physician for the Denver Broncos. So far, however, solid evidence to support such claims is lacking. "There's a great deal of hype and a great deal of testimony, but there isn't a great deal of evidence," says Hellman. The main problem, researchers say, is that they cannot possibly study the effects of HGH in the quantities and combinations that athletes are believed to be using it.
Nor is it possible to take the findings from studies done on the elderly and the sick and apply them to elite athletes. The research that showed an increase in muscle mass and reduction of body fat in older men, for example, failed to show a corresponding increase in strength, endurance or exercise capability. In other words, bigger does not always mean stronger or faster. That has not dissuaded professional athletes from injecting the drug, however. By some estimates, more than 7 percent of major-league baseball players have used HGH. Its popularity is no doubt fueled in part by the fact that there are currently no effective tests for the substance.
Even if there were, some wonder whether it makes sense to forbid the use of HGH by professional athletes in the first place. Since there is no scientific evidence that it enhances performance (there's no evidence that it aids recovery, either), they ask, what's the point of banning it? "Elite athletes know their own bodies," says Charles Yesalis, a sports-doping expert at Penn State. "Maybe we should let them do what they want." Perhaps. Or at least until the science catches up with the myths.