Comparison of the reactions induced by psilocybin and LSD-25 in man

Abstract

The reaction induced by oral administration of 57 to 114 mcgm/kg of 0-Phosphoryl-4-hydroxy-N-dimethyltryptamine (psilocybin) has been compared with that induced by a placebo and LSD-25 (1.0 to 1.5 mcgm/kg) in 9 subjects. Both LSD and psilocybin caused elevations in body temperature, pulse and respiratory rates, and systolic blood pressure. Threshold for elicitation of the kneejerk was decreased by both drugs. After both drugs, abnormal mental states characterized by feelings of strangeness, difficulty in thinking, anxiety, altered sensory perception (particularly visual), elementary and true visual hallucinations, and alterations of body image were reported by the subjects. The effects of psilocybin did not persist as long as those of LSD. LSD is 100 to 150 times as potent as psilocybin. © 1959, Springer-Verlag. All rights reserved.