Myth Meets Science.(Health)(human growth hormone)

Byline: Jeneen Interlandi

Everybody's talking about human growth hormone, and lots of people are using it. But what does it do?

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…