A Phase 1 interventional study of LSD and Psilocybin in Healthy, sponsored by University Hospital, Basel, Switzerland. Completed at 1 site in Switzerland. Open to participants aged 25 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-01-24.
Sponsored by University Hospital, Basel, Switzerland · Phase 1, Interventional, and Basic science
LSD, psilocybin and mescaline are widely used for recreational and ethnomedical purposes. All three substances are thought to induce prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. However, there are differences in the substances' molecular structures and receptor activation profiles which may induce differential subjective effects. To date, there are no modern studies comparing LSD, psilocybin and mescaline directly within the same clinical study and research subjects using validated psychometric tools. Therefore, the LPM-Study compares the acute effects of LSD, psilocybin, mescaline and placebo in a double-blind, placebo-controlled, 4-period cross-over design with four treatment conditions: 1) 100 μg LSD, 2) 20 mg psilocybin, 3) 300 or 500 mg mescaline, and 4) placebo.
LSD (lysergic acid diethylamide), psilocybin (the active substance in "magic mushrooms") and mescaline (the active substance in Peyote and San Pedro cacti) are serotonergic hallucinogens widely used for recreational and/or ethnomedical purposes. LSD, psilocybin and mescaline are thought to induce prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. However, there are differences in their molecular structures (LSD: ergoline, psilocybin: tryptamine; mescaline: phenethylamine)and receptor activation profiles which may induce different subjective effects. To date, there are no modern studies comparing these three substances directly within the same clinical study and research subjects using validated psychometric tools. Therefore, the LPM-Study compares the acute effects of LSD, psilocybin, mescaline and placebo in a double-blind, placebo-controlled, 4-period cross-over design with four treatment conditions: 1) 100 μg LSD, 2) 20 mg psilocybin, 3) 300 or 500 mg mescaline, and 4) placebo. The main objective of this study is to determine whether LSD, psilocybin and mescaline produce qualitatively similar subjective alterations of mind and associated brain activity patterns despite their unique receptor activation profiles. The study investigates psychological (psychometry), physiological and neuronal (magnetic resonance imaging) variables. The LPM-Study provides insight into the acute effects profiles of three serotonergic hallucinogens. It will enhance the understanding of psychedelic-induced altered states of consciousness in humans and will be relevant for the fields of psychiatry, psychology, and forensic toxicology.
University Hospital, Basel, Switzerland is the lead sponsor of 968 studies on the registry; 191 are open to participants now.
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Exclusion Criteria:
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Drug: LSD
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Drug: Psilocybin
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Drug: Mescaline
Cross-over within-subject design with all treatment conditions, separated by a wash-out phase of at least 10 days
Other: Placebo
LSD 0.1 mg per os, single dose OR Psilocybin 20 mg per os, single dose OR Mescaline 300 mg per os, single dose OR Placebo
Psilocybin 20 mg per os, single dose
Mescaline 300 mg or 500 mg per os, single dose
Placebo (Mannitol)
5 Dimensions of Altered States of Consciousness (5D-ASC)
5D-ASC subscale ratios
Time frame: 18 months
fMRI resting state functional connectivity (RSFC)
Spontaneous low-frequency fluctuations in BOLD signal during resting state
Time frame: 18 months
Visual Analog Scale (VAS)
Assesses the intensity and duration of subjective effects on a scale from 0% - 100% with higher scores representing more intense effects
Time frame: 18 months
States of Consciousness questionnaire (SCQ)
Assesses the emergence and intensity of phenomenons occurring in altered states of consciousness on a 6-point Likert scale ranging from 0 ("not at all") to 5 ("extremely")
Time frame: 18 months
Blood pressure
Assessment of sympathetic activation
Time frame: 18 months
Heart rate
Assessment of sympathetic activation
Time frame: 18 months
Body temperature
Assessment of sympathetic activation
Time frame: 18 months
Pupil size
Assessment of sympathetic activation
Time frame: 18 months
Drug plasma levels
Plasma levels of investigational drugs
Time frame: 18 months
Oxytocin levels
Levels of oxytocin in blood plasma
Time frame: 18 months
Blood-derived neurotrophic factor (BDNF)
Blood plasma levels of BDNF
Time frame: 18 months
Renal clearance values
Renal clearance values of investigational drugs through urine recovery
Time frame: 18 months
NEO-Five-Factor-Inventory (NEO-FFI)
Assesses personality traits
Time frame: 18 months
Freiburger Persönlichkeitsinventar (FPI)
Assesses personality traits
Time frame: 18 months
Saarbrücker Persönlichkeitsfragebogen (SPF)
Assesses personality traits
Time frame: 18 months
Adjective Mood Rating Scale (AMRS)
Assesses the occurrence and intensity of 60 moods on a 4-point Likert scale ranging from "not at all" to "extremely"
Time frame: 18 months
Mysticism Scale (MS)
Assesses the occurrence and intensity of mystical qualities in altered states of consciousness on a 9-point Likert scale ranging from -4 ("extremely inapplicable") to +4 ("extremely applicable"), with higher values indicating a more intense experience
Time frame: 18 months
Elliot Humility Scale (EHS)
Assesses the personality trait humility through 13 items on a 5-point Likert scale ranging from "strongly disagree" to "strongly agree"
Time frame: 18 months
Jankowski Humility Scale (JHS)
Assesses the personality trait humility through 18 items on a 5-point Likert scale ranging from "not at all" to "strongly"
Time frame: 18 months
Arnett Inventory of Sensation Seeking (AISS-d)
Assesses personality traits
Time frame: 18 months
Plan to share: No
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This study is completed, as verified in Jan 2024. You cannot join it, but the record below documents what was studied.
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University Hospital, Basel, Switzerland