There's more talk than ever these days about performance-enhancing substances, chief among them being HGH and steroids (aka "juice"). Veteran pitcher Roger Clemens just returned from a trip to the hill of a different kind to testify before a Congressional committee, and it seems as though the case against slugger Barry Bonds may again be opened. But, aside from aging sports figures, fading Hollywood stars, and every single contestant in the Mr. Olympia bodybuilding contest, who else uses these drugs?

As for HGH, an estimated 30,000 people in the U.S. have visited so-called "anti-aging" clinics to be administered HGH. The associated health risks are incredibly high, yet vanity appears to win out over better judgment in many of these cases. Steroids, which have been linked to a number of health risks of their own, are used by far more people, most of which are neither old nor seemingly in possession of poor judgment.

Based on the results of a new study, the vast majority of steroid users are educated men in their 30s with an average annual income of close to six figures. Without an athletic career on the line, a movie legacy to cling to, or a bodybuilding title to defend, thousands upon thousands of people put their health at risk in order to broaden their shoulders. And, because steroids are a psychologically addictive drug, many users have great difficulty stopping once they have witnessed results.