This book provides a vital, critical criminological contribution to ongoing discussions regarding the so-called 'psychedelic renaissance' by affording an in-depth ethnographic study of unregulated contexts of psychedelic drug use. It identifies and examines three case studies representing prominent contexts of unregulated, non-clinical psychedelic drug use including: the individual psychedelic drug use of military veterans, the touristic consumption of ayahuasca 'shamanism' in Amazonian Peru, and the operation of psychedelic retreat companies within the 'spiritual supermarket' realm. Employing qualitative ethnographic methods, this book examines the various meanings being ascribed to psychedelic drugs within these unregulated contexts, exploring how their use and effects are being narratively constructed by users, facilitators, and other prevalent actors, and critically highlighting the complex socio-cultural factors at play. This book may be of key interest to any social scientist currently engaged in critical debates and research regarding psychedelic drugs, their use, and the contemporary psychedelic 'renaissance' phenomenon, and to any clinician looking for an expanded, qualitative discussion of psychedelic drug use beyond the quantitative, experimental, and clinical fields.