This article places a spotlight on lysergic acid diethylamide (LSD) and American mental health in the 1970s, an era in which psychedelic science was far from settled and researchers continued to push the limits of regulation, resist change and attempt to revolutionise the mental health market-place. The following pages reveal some of the connections between mental health, LSD and the wider setting, avoiding both ascension and declension narratives. We offer a renewed approach to a substance, LSD, which bridged the gap between biomedical understandings of ‘health’ and ‘cure’ and the subjective needs of the individual. Garnering much attention, much like today, LSD created a cross-over point that brought together the humanities and arts, social sciences, health policy, medical education, patient experience and the public at large. It also divided opinion. This study draws on archival materials, medical literature and popular culture to understand the dynamics of psychedelic crossings as a means of engendering a fresh approach to cultural and countercultural-based healthcare during the 1970s.