What you need to know
Performance-enhancing substances are also known as ergogenic aids. Ergogenic aids are defined as any substance taken into the body by an abnormal route and/or in excessive amounts, with the intention of increasing performance. These substances can be normal prescription medications at supra-physiologic doses, illegal drugs, over-the-counter medications or dietary supplements.
Under the Dietary Supplement Health and Education Act of 1994 (DSHEA) substances sold as supplements or "natural substances" do not require FDA approval prior to being introduced into the U.S. market. They also do not require proof of their claims with validated research and are generally considered safe until proven to be harmful (ephedrine is a recent example). These products frequently are "contaminated" with substances or quantities not listed on the label, which can be problematic for individuals that undergo drug testing.
In the 1990s the supplement industry brought in approximately $1.2 to $3 billion; currently the industry is estimated to bring in $18 billion a year. This is thought to coincide with the rise of supplement use in high school and middle school students.