This randomized, double-blind, placebo-controlled cross-over study compared the acute effects of mescaline (300 and 500 mg), LSD (100 µg), and psilocybin (20 mg) in 32 healthy participants. Subjective effects of 500 mg mescaline, LSD, and psilocybin were comparable. Psilocybin caused a greater increase in diastolic blood pressure than LSD, while LSD showed a trend toward increased heart rate compared to psilocybin. Mescaline had the longest duration of action (mean: 111.1 h), followed by LSD (mean: 82 h) and psilocybin (mean: 50 h). No qualitative differences in altered states of consciousness were found between the substances at equivalent doses. The results suggest that differences in pharmacological profiles do not significantly impact subjective experience.

Laura Leyl, Friederike Holze, Anna M. Becker, Isabelle Strumm, Aaron Klabier, Fabio Coviello, Sophie Dierbach, Jan Thoman, Urs Duthaler, Dino Luethi, Nimmy Varghese, Anne Eckert, Matthias E. Liechti