Athletes have been using performance-enhancing substances for as long as there has been athletic competition. In fact, the prevalence of the use of performance-enhancing substances has increased over time. Classified as supplements, prescriptions medications and banned/illicit substances, performance-enhancing substances have found their uses in the world of sports, for both theoretical and proven reasons.

Supplements can be packaged as such when sold as a beneficial supplement and not defined as a drug or proclaimed to treat a medical condition. Adolescent athletes most commonly utilize supplement performance-enhancing substances. Currently used supplements include creatine, androstenedione, antioxidants, and amino acids. Creatine, naturally found in the body and utilized for energy production via its conversion to phosphocreatine, has been used in the sporting world since 1992. The use of creatine in the adolescent population is increasing due to several potential reasons, including its claim as a “natural” supplement, its easy access on the Internet, and its routine use by collegiate and professional athletes. The premise behind its use is that the added creatine allows for more readily available aerobic energy and decreased use of anaerobic metabolism, as increased levels of phosphocreatine lead to increased conversion of adenosine diphosphate (ADP) to adenosine triphosphate ATP. Creatine, however, does not work without strength training, and its side-effect profile is still unknown at this time. Recent reports suggest a reversible renal dysfunction related to decreased glomerular filtration rate. Androstenedione, also available for use for some time, is believed to work as a precursor to testosterone; however, it remains on the supplement list due to lack of efficacy in clinical trials. Androstenedione use in a prepubertal athlete could, in theory, cause premature puberty or premature closure of the growth plates. Amino acid supplements are often used to achieve a positive nitrogen balance; antioxidants are used for their immunity-promoting properties.