On June 23, 2023 the U.S. Food and Drug Administration (FDA) published a draft guidance document with foundational considerations for researchers that are developing psychedelic drugs for the treatment of medical conditions. The guidance document applies to clinical trials that will be conducted under investigational new drug applications, including clinical trials that are not intended to support marketing applications. Notably, the use of the term “psychedelic” in the guidance document is intended to encompass “classic psychedelics” that are understood to be 5-HT2 agonists (e.g., psilocybin and lysergic acid diethylamide (LSD)) as well as entactogens or empathogens (e.g., methylenedioxymethamphetamine (MDMA)). This is the first FDA draft guidance that discusses designing clinical trials for psychedelic drugs.