Performance-enhancing drugs (PEDs) have been used by athletes for as long as sporting competitions have existed. To protect the health and safety of athletes and promote fair play, banned substance lists were developed that include several classes of PEDs. Evidence shows that a majority of athletes use dietary supplement products to aid their training and support their health. Evidence also indicates that use of some dietary supplements carries a risk because the products may contain banned PEDs. Consumers and athletes should weigh a number of considerations before purchasing and consuming dietary supplements to protect their health, reputation, and the spirit of fair competition.The American Medical Association designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit™ available through the AMA Ed Hub TM . Physicians should claim only the credit commensurate with the extent of their participation in the activity.Why Performance-Enhancing Drug Use Matters Performance-enhancing drugs (PEDs) have been used by athletes for decades, even centuries. To promote fair play-an issue precipitated by the death of an athlete-the International Olympic Committee (IOC) in 1967 banned the use of PEDs, established a new Medical Commission, and created a list of banned substances. 1 Mandatory testing of all athletes began at the 1968 Olympic Games, and drug-testing programs were initiated all over the world in the following years to further promote fair play and to safeguard the health and safety of athletes. 2