A Phase 1 interventional study of 0mg Psilocybin Capsule + 0.00% BAC Alcoholic Drink and 1mg Psilocybin Capsule + 0.00% BAC Alcoholic Drink in Psilocybin Intoxication, sponsored by Johns Hopkins University. Not yet recruiting at 1 site in United States. Open to participants aged 21 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Johns Hopkins University · Phase 1, Interventional, and Basic science
This study will evaluate the subjective and behavioral effects of psilocybin relative to placebo and alcohol.
This clinical laboratory study will be double-blind, double-dummy, placebo-controlled and will utilize a within-subjects experimental design. Participants will complete 6 outpatient drug administration sessions that will consist of self-administration of oral capsule containing placebo or psilocybin (0, 1, 5, 15, 25mg) and an alcoholic drink containing alcohol to achieve a 0.00% or 0.08% blood alcohol concentration. No drug combinations will be administered during this study. Primary outcomes include performance on cognitive and psychomotor assessments, subjective drug effects, simulated driving performance, and impact on blood pharmacokinetics.
Johns Hopkins University is the lead sponsor of 1,809 studies on the registry; 314 are open to participants now.
Of its 208 completed or terminated interventional studies of FDA-regulated products, 144 (69%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Participants ingest an oral capsule containing 0mg psilocybin and ingest a beverage containing alcohol dosed to 0.00% BAC
Drug: 0mg Psilocybin Capsule + 0.00% BAC Alcoholic Drink
Participants ingest an oral capsule containing 1mg psilocybin and ingest a beverage containing alcohol dosed to 0.00% BAC
Drug: 1mg Psilocybin Capsule + 0.00% BAC Alcoholic Drink
Participants ingest an oral capsule containing 5mg psilocybin and ingest a beverage containing alcohol dosed to 0.00% BAC
Drug: 5mg Psilocybin Capsule + 0.00% BAC Alcoholic Drink
Participants ingest an oral capsule containing 15mg psilocybin and ingest a beverage containing alcohol dosed to 0.00% BAC
Drug: 15mg Psilocybin Capsule + 0.00% BAC Alcoholic Drink
Participants ingest an oral capsule containing 25mg psilocybin and ingest a beverage containing alcohol dosed to 0.00% BAC
Drug: 25mg Psilocybin Capsule + 0.00% BAC Alcoholic Drink
Participants ingest an oral capsule containing 0mg psilocybin and ingest a beverage containing alcohol dosed to 0.08% BAC
Drug: 0mg Psilocybin Capsule + 0.08% BAC Alcoholic Drink
Participants will self-administer a capsule containing 0mg psilocybin and a drink that contains alcohol dosed to 0.00% BAC.
Participants will self-administer a capsule containing 1mg psilocybin and a drink that contains alcohol dosed to 0.00% BAC.
Participants will self-administer a capsule containing 5mg psilocybin and a drink that contains alcohol dosed to 0.00% BAC.
Participants will self-administer a capsule containing 15mg psilocybin and a drink that contains alcohol dosed to 0.00% BAC.
Participants will self-administer a capsule containing 25mg psilocybin and a drink that contains alcohol dosed to 0.00% BAC.
Participants will self-administer a capsule containing 0mg psilocybin and a drink that contains alcohol dosed to 0.08% BAC.
Driving performance as assessed by standard deviation of lateral position (SDLP)
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. SDLP (measured in cm) will be determined during each drive. This measure is a composite index of lateral control and incorporates lane weaving, swerving, and over-correcting. SDLP is the gold standard of quantifying the magnitude of driving impairment from drugs and alcohol and has excellent predictive validity to actual driving. Scores range from 0 to no upper limit. Higher scores represent higher magnitude of driving impairment.
Time frame: Baseline, 1, 3, 6, and 24 hours post-dosing
Driving performance as assessed by global drive score during the simulated driving task
Driving impairment will be assessed using a composite driving score, with higher scores indicating greater impairment. The composite score is calculated by converting individual driving outcomes (see primary and secondary driving outcomes) into standardized z-scores and averaging these values to generate an overall composite score. Individual z-scores have a mean of 0 and a standard deviation (SD) of 1 in the reference sample used for standardization. The composite score has an expected mean of 0 in the reference sample, while its SD depends on the correlations among the individual driving outcomes and is not necessarily 1.
Time frame: Baseline, 1, 3, 6, and 24 hours post-dosing
Total Clues and Cues exhibited during Standardized Field Sobriety Tests (SFSTs)
Total Clues and Cues will be assessed across six field sobriety tests and summed into a single value. The maximum number of possible clues and cues is 29. Greater values indicate greater impairment of behavioral function during field sobriety tests.
Time frame: Baseline, 1, 3, 6, and 24 hours post-dosing.
Drug Effect Questionnaire (DEQ) - Feel Drug Effect
The DEQ will be used to obtain subjective ratings of "feel drug effects". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Baseline, 0.5, 1, 1.5, 2, 3, 4, 5, 6, and 24 hours post-dosing.
Drug Effect Questionnaire (DEQ) - Drug Liking
The DEQ will be used to obtain subjective ratings of "drug liking". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Baseline, 0.5, 1, 1.5, 2, 3, 4, 5, 6, and 24 hours post-dosing.
Drug Effect Questionnaire - Confidence to Drive
The DEQ will be used to obtain subjective ratings of "confidence to drive". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
Time frame: Baseline, 0.5, 1, 1.5, 2, 3, 4, 5, 6, and 24 hours post-dosing.
Whole Psilocin Concentrations - THC Concentrations
Blood psilocin concentrations will be measured to assess changing in blood concentrations following drug administration.
Time frame: Baseline, 0.5, 1, 1.5, 2, 3, 4, 5, 6, and 24 hours post-dosing.
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.