List of banned substances in Major League Baseball
Major League Baseball's drug policy prohibits players from using, possessing, selling, facilitating the sale of, distributing, or facilitating the distribution of any Drug of Abuse and/or Steroid. Any and all drugs or substances listed under Schedule II of the Controlled Substances Act are considered drugs of abuse covered by the Program.
Source: Wikipedia — List of banned substances in Major League Baseball (CC BY-SA 4.0)