There is growing recognition that the judicious use of the hallucinogen treatment model, when administered under optimal conditions, may achieve successful therapeutic outcomes even among patients who are refractory to conventional treatments. The implications for the future of psychiatry — and even other fields in medicine — are compelling. An integrative approach will be required, incorporating all that has been learned from those who have explored this inner terrain from other times and other cultures, as well as from our scientific and clinical predecessors a half-century ago. In today’s world, we also have access to an extraordinary neuroscientific and medical technology that allows us to examine comprehensively the effects of hallucinogens, their mechanisms of action, and putative models for healing. Recent interest in microdosing regimens, in which a classic hallucinogen may only be administered sporadically at supposedly subthreshold dosages, raises new questions that await answers. Future research into mechanisms of action, as well as the potential medical and psychiatric uses of the hallucinogen treatment model, may over time achieve a significant impact on how we facilitate health and healing for both the individual and the collective.