Clinical research on psychedelic-assisted psychotherapy is rapidly advancing in the USA, with two drugs, psilocybin and MDMA, progressing through a structure of FDA-approved trials on a trajectory toward Drug Enforcement Agency rescheduling for therapeutic use. Researcher’s and clinician’s personal use of psychedelics was cited as a potential confound in psychedelic research studies conducted in the 1950s and 1960s, a concern which contributed to the cessation of this research for some 20 years. Currently, there is no empirical research on personal use of psychedelics by current academic researchers and clinicians; its influence is undocumented, unknown, and undertheorized. This paper explores the history of personal use of psychedelics by clinicians and researchers, the potential impact of personal use on psychedelic-assisted psychotherapy and research, and the rationale for opening an academic discussion and program of research to investigate the role of personal use. We propose that there are factors unique to psychedelic-assisted therapy such that training for it cannot neatly fit into the framework of modern psychopharmacology training, nor be fully analogous to psychotherapy training in contemporary psychological and psychiatric settings. We argue that scientific exploration of the influence of therapists’ first-hand experience of psychedelics on psychedelic-assisted therapy outcomes is feasible, timely, and necessary for the future of clinical research.