U.S. Anti-Doping Agency (USADA)

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How Does a Substance Become Prohibited?

USADA is one of the many organizations worldwide that is a signatory to the World Anti-Doping Code, which is the guiding document that standardizes anti-doping policies, rules, and regulations for public authorities and sport organizations around the world.

Under the World Anti-Doping Code, the World Anti-Doping Agency (WADA) issues an annual List of Prohibited Substances and Methods, known as the Prohibited List, which is one of five International Standards. The Prohibited List outlines substances and methods that are prohibited at all times, in-competition only, and in particular sports. The substances and methods on the Prohibited List are identified under various categories, including Anabolic Agents, Hormone and Metabolic Modulators, Stimulants, and others.

Annual Review Process

On an ongoing basis, WADA’s Prohibited List Expert Group reviews scientific and medical research, while also consulting with others in the anti-doping community, to provide recommendations and guidance on updates to the Prohibited List. Advice is then provided to and considered by the Health, Medical, and Research Committee before WADA finalizes and releases the Prohibited List by October 1 each year. This timing gives stakeholders three full months before the updated List goes into effect on January 1 of the following year.


Under the WADA Code, a substance or method may be added to the WADA Prohibited List if it meets at least two of the following three criteria:

  • It has the potential to enhance or enhances sport performance.

    Before adding a substance or method to the Prohibited List, WADA examines emerging doping threats and reviews research from scientists around the world. This research helps WADA determine if a substance or method indeed provides performance-enhancing effects.

    In 2016, for example, the review and consultation process allowed WADA to determine that 5α-androst-2-ene-17-one, commonly known as “Delta-2” or 2-androstenone, should be added as an example of a metabolite of DHEA, more recently found in dietary supplements and prohibited at all times.

    Due to research limitations and/or ethical concerns, it’s not always possible to design human research studies to identify the performance-enhancing qualities of all substances. Therefore, in some cases, the Prohibited List Expert Group must make judgement calls based on comparisons to other similar prohibited substances to determine whether inclusion is warranted.

    Over time, the use of substances for performance enhancement can also become part of the culture in a specific sport, which is why WADA and anti-doping organizations worldwide maintain the Monitoring Program. This program identifies trends of substance use in specific sports by testing for substances on the monitoring list, analyzing both in and out-of-competition samples, and aggregating the results by sport.

  • It represents an actual or potential health risk to the athlete.

    Not only do substances and methods on the Prohibited List enhance performance in sport, but many of them are also associated with serious health risks and unknown side effects.

    The use of prohibited substances for performance enhancement and injury recovery reasons can pose health risks ranging from immune and toxicity reactions, to infection and death. Furthermore, many of these prohibited substances are also not approved by the FDA for human consumption, meaning they have not been thoroughly evaluated for safety and efficacy. Some may be branded as for “research/laboratory use only,” indicating that they are not produced for human consumption according to Current Good Manufacturing Practice (“CGMP”) regulations and have not undergone any human clinical safety or efficacy evaluation.

  • It violates the spirit of sport.

    When WADA and its stakeholders evaluate items for the Prohibited List, one of the primary forces behind those decisions is the commitment to uphold the 'Spirit of Sport,’ or the celebration of the human spirit, body, and mind. Essentially, no athlete should be using a prescription or non-prescription drug in a way that undermines the commitment all athletes share to uphold the values of clean sport.

    The World Anti-Doping Code further defines the spirit of sport as the pursuit of human excellence through the dedicated perfection of each person’s natural talents. Only when the playing field is level can people experience the true value of sport, including its power to inspire joy, build character, teach teamwork, and instill respect. Doping is fundamentally contrary to the spirit of sport because it puts winning above all else.

Prohibited List Resources

To learn more about prohibited substances and methods, you can search the status of your medications on GlobalDRO.com or find information about the risks associated with supplements on Supplement Connect.

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