AT THE MENTION of performance- and appearance-altering drugs, also known as PAAs, most people think only of steroids. While steroids are widely used within sports, they are only one type of illegal or banned PAA drug. Illegal PAAs include sex hormones and human growth hormones, and more addictive and dangerous drugs like amphetamines. All PAAs change the way an athlete looks or performs.

Sex hormones

Both the male hormone testosterone and the female hormone progesterone change the way an athlete looks and performs, but in different ways. Testosterone is taken by athletes like weight lifters and sprinters who want to build body size and strength. Progesterone, however, is taken by female gymnasts who want to keep their bodies small and childlike.

Testosterone is produced by the testes, the male reproductive glands. Like steroids, testosterone causes the body to build muscle...