Doping refers to the use of banned substances or techniques to illegally improve athletic performance. In competitive sports, doping is considered cheating and is widely regulated by organizations that oversee sporting competitions. The most common prohibited substances for doping in sport are anabolic steroids, which increase muscle mass and physical strength. Other substances that are banned from use include human growth hormones, stimulants, and diuretics. Doping can have harmful and long-lasting side effects, such as irregular heart rhythm, elevated blood pressure, heart attack, sudden death, insomnia, anxiousness, depression, aggressive behavior, suicide, headache, addiction with withdrawal, psychosis, tremor, dizziness, stroke, and more.

The purpose of an anti-doping program is to protect the athletes fundamental right to participate in doping-free sport and promote health, fairness, and equality for athletes worldwide. The organizations that monitor for doping violations vary between sports, and the largest anti-doping organization is the World Anti-Doping Agency (WADA) . WADA has developed a coordinated, worldwide anti-doping program.

It is important to note that doping is not limited to sports. In semiconductor production, doping is the intentional introduction of impurities into an intrinsic semiconductor for the purpose of modulating its electrical, optical, and structural properties). Additionally, doping substances can be illegally produced, trafficked, and distributed, posing a serious health risk to both professional and amateur sportspeople.