Active, not recruitingPhase 1

Comparing the Effects of Psilocin and Psilocybin in Healthy Adults

NCT05317689 · University of California, San Francisco

Closed to entry

Status

Not accepting participants

Phase 1

Phase

Target enrolment

Study sites

1 US states

What it is testing

Summary

To compare the physiological and psychological effects of psilocin taken orally by pill or sublingually by dissolving a tablet under the tongue to those of psilocybin taken by pill in healthy adults.

Summary as written by the trial’s own sponsor and published on ClinicalTrials.gov API v2. It is the sponsor’s description, reproduced unedited, not an assessment by this site.

What counts as success

Primary outcome measures

Physiological Effects
Measured over Baseline to 8 hours following drug delivery
Physiological Effects
Measured over Baseline to 8 hours following drug delivery
Psychological Effects
Measured over Baseline to 4 weeks after drug delivery
Psychological Effects
Measured over Baseline to 4 weeks after drug delivery
Psychological Effects
Measured over Baseline to 4 weeks after drug delivery
Psychological Effects
Measured over Baseline to 4 weeks after drug delivery
Psychological Effects
Measured over Baseline to 4 weeks after drug delivery
Adverse Effects
Measured over Baseline to 24 hours after dosing session

A trial succeeds or fails on its primary outcome, declared in advance. Everything else it reports is secondary by definition.

Who can take part

Eligibility, as published

25 Years to 50 Years

Ages

All

Sex

Accepted

Healthy volunteers

Inclusion Criteria: * Age 25 to 50 * Comfortable speaking and writing in English * Commit to attending all study visits and remote data collection tasks * No planned surgeries during the study * Had at least one prior experience with a psychedelic substance * Generally mentally and physically healthy * Agree to abstain from THC, CBD, or nicotine products during study Exclusion Criteria: * Participated in another clinical trial within 30 days of entry to this trial * Regular use of medications that may have problematic interactions with psilocybin, including but not limited to dopamine agonists, MAO inhibitors, N-methyl-D-aspartate (NMDAR) antagonists, antipsychotics, and stimulants * A health condition that makes study unsafe or unfeasible, determined by study physicians

Where

1 study site

Facility	City	Region	Country
University of California, San Francisco	San Francisco	California	United States

On the registry

Contact the trial directly

This site does not enrol anyone and is not involved in this trial. To ask about taking part, use the sponsor’s own contact details on the official registry record, which is also where the most current version of everything above lives.

Before you do, the preparation checklist lists what a site will ask you on a first call and what is worth asking them. It is free and collects nothing.

NCT05317689 on ClinicalTrials.gov →

Last updated in the registry 2025-06-10. Registry records change; this page reflects the data build of 2026-08-25.

Where this trial sits

Substance

Psilocybin

Recruiting in

California115

All 3 trials from University of California, San Francisco →