Muscle Madness

By Christine Gorman

Two images kept flashing through my head last week. The brighter one was filled with the sheer exuberance of a bunch of kids from Toms River, N.J., as they pursued their ultimately successful dream of winning the World Series in Little League Baseball. The darker one stemmed from Mark McGwire's defiant confirmation that he's been taking a supplement called androstenedione, which its manufacturers claim will boost testosterone levels. While it's perfectly legal in the U.S. and the major leagues for McGwire to take the supplements, it sends an absolutely wrong health message to kids everywhere. If he does beat Roger Maris' home-run record, there will always be--for me, anyway--a mental asterisk next to his name.

Why am I being so hard-nosed about this? Androstenedione is not a vitamin, a mineral or a protein. It's an honest-to-goodness steroid. The only chemical difference between it and testosterone, which is found in varying degrees in both men and women, is a single hydrogen atom. That helps explain why androstenedione is banned by the National Football League and the International Olympic Committee. If you find it surprising that you can buy a steroid over the counter, you can thank the U.S. Congress, which in 1994 barred the Food and Drug Administration from regulating the "dietary supplements" industry.

So what proof is there that androstenedione pills are safe or effective? None. In fact, this summer General Nutrition Centers, a national chain of health-food stores, ordered its franchisees not to sell the supplement. "We're not yet satisfied with the safety of this product," says John Troup, vice president for scientific affairs at the chain's corporate parent. "We don't know its effect on the liver, cardiovascular system or secondary sexual characteristics."

This much is known, however. By itself, androstenedione won't do very much for your muscles or your libido. But once it gets into the bloodstream, the body can convert small amounts of it into testosterone, which does indeed build lean-muscle mass and boost the sex drive of both men and women. The trick is getting it into the bloodstream. First it has to get past the stomach and intestines, which break down a lot of androstenedione, rendering it ineffective. Some manufacturers are experimenting with ways to stabilize the steroid so it won't be so easily destroyed during digestion. Most users attempt to get around this little snag by taking more pills. And there are other supplements available that are chemically similar to androstenedione and that may boost testosterone more effectively.

Trouble is, pumped-up testosterone levels can prove counterproductive. The body has lots of different feedback loops that generally keep it from making too much of any one compound. If testosterone levels stay high for a long time, a chemical switch in the brain is tripped that signals the testes to stop making the hormone. That can cause them to shrink and may make it difficult for users to produce their own testosterone naturally. As if that weren't enough, excess testosterone can accelerate the growth of prostate tumors that might otherwise have taken years to form.

But I keep coming back to the kids. If your sons or daughters take androstenedione and it boosts their testosterone levels, they could regret it for the rest of their lives. Artificially high levels of testosterone have been shown to permanently damage the heart, trigger liver failure and stunt a teenager's growth. All of which is too great a price to pay for any game.

See time.com/personal for more on androstenedione. Send e-mail about this article to Christine at [email protected]