Use of dietary supplements has become common practice among adolescent athletes in the United States. Concern has arisen regarding safety in adolescents in light of the fact that supplements are not required to meet usual US Food and Drug Administration requirements for standard pharmaceuticals. Furthermore, advertised ergogenic gains are based on little or no scientific evidence. Creatine, anabolic steroids, androstenedione, dehydroepiandrosterone, caffeine, ephedrine-type alkaloids, calcium b-hydroxy-b-methybutyrate, and human growth hormone are reviewed. Although some studies have indicated performance benefit in particular athletic situations, there are few available data in adolescents. Furthermore, the few safety studies of these supplements do not include adolescents. Adolescents may be at particular risk when using anabolic steroids and caffeine-ephedra combinations. Research has demonstrated effective education programs can reduce adolescents' intentions to use dietary supplements.