Anti-doping regulation has become a critical element of contemporary sport, conveying what substances and methods athletes may use. Although this form of regulation is often synonymous with banning performance enhancing substances and methods, the World Anti-Doping Agency (WADA), the global authority tasked with formulating policies on drug use in sports also regulates illicit drugs, including those considered non-performance enhancing. This paper examines how the inclusion of illicit drugs on the WADA Prohibited List falls under the agency's mandate by focusing on how the agency justifies the prohibition of substances more generally. In so doing, it highlights inconsistencies in the criteria used to evaluate whether or not substances ...