US NIMH Finds LSD, Psilocybin, and Mescaline Have Similar Qualitative Effects

Study finds psilocybin and psilocin cause qualitative effects similar to mescaline, but that mescaline is longer lasting and less potent. The data also showed psilocin is more potent and shorter acting than psilocin.

May 1962

A study conducted by the US National Institute of Mental Health (NIMH) finds that LSD, mescaline, and psilocybin have similar qualitative effects. The also found the effects of psilocin and psilocybin to be shorter in duration and less potent than LSD or mescaline. The data also showed psilocin is about 1.4 times more potent than psilocybin. This is approximately the same ratio as their molecular weights (i.e., based on their molecular weights, they are equipotent).