Performance-enhancing drugs: understanding the risks.

To help clinicians understand the risks associated with performance-enhancing drugs, this overview covers prohibited lists of substances and methods, therapeutic use exemptions, the legitimate indications and adverse effects, including for megadose and polypharmacy doping of stimulants, anabolic steroids, erythropoiesis-stimulating agents, and growth hormone and ways in which physicians or patients risk committing anti-doping rule violations inadvertently.