Study Summary

Four healthy participants were included in this double-blind, placebo-controlled study examining the dose-related effects of inhaled salvinorin A. Participants were administered ascending doses of salvinorin A (0.375 - 21 μg/kg) or placebo across twenty sessions with a washout period of at least one day between sessions. Placebo was administered once every five sessions for a total of four sessions, therefore participants received the treatment drug in sixteen of the twenty sessions. Physiological drug effects were assessed by measuring heart rate and blood pressure, as well as resting and kinetic tremor severity on a 5-point scale. Drug strength was assessed using participant ratings on an 11-point scale and subjective drug effects were assessed using the Hallucinogen Rating Scale (HRS) and the Mysticism Scale. Salvinorin A did not significantly increase heart rate or blood pressure. While subjective reports of drug effects did show some similarities to classic hallucinogens, including mystical-type effects, participant experiences were unique and often characterized by disruptions in vestibular and interoceptive signals and unusual recurring themes, such as revisiting childhood memories. Despite these intense subjective effects, participants were largely behaviorally inactive.