Skip to main content
OpenTrials
Active, Not Recruiting

NCT Number: NCT05317689

Comparing the Effects of Psilocin and Psilocybin in Healthy Adults

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Notify Me

Key information

Conditions

Healthy

Age range

25 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

University of California, San Francisco

San Francisco, California, 94143, United States

About this study

The primary goal of this study is to compare the physiological and psychological effects of psilocin taken orally by pill or sublingually dissolved under the tongue to those of psilocybin taken by pill. Twenty participants, ages 25 to 50, with one previous experience with psychedelics, and who meet all other inclusion and exclusion criteria at screening will be enrolled. After baseline assessments, participants will engage in preparatory visits with trained facilitators, followed by drug administration, supervised by the facilitators and a clinician who will conduct safety monitoring throughout. Participants will then complete assessment and integration sessions with the facilitators in order to help process the experience. The same preparation, procedures, integration, and supervision will be repeated up to three more times with each participant.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Psilocin

Drug

17.5mg oral psilocin with psychological support and physiological monitoring

Psilocybin

Drug

25mg oral psilocybin with psychological support and physiological monitoring

Sublingual Psilocin

Drug

2.18mg - 4.36mg sublingual psilocin with psychological support and physiological monitoring

Primary outcomes

  1. Physiological Effects

    Time frame: Baseline to 8 hours following drug delivery

    blood pressure

  2. Physiological Effects

    Time frame: Baseline to 8 hours following drug delivery

    heart rate

  3. Psychological Effects

    Time frame: Baseline to 4 weeks after drug delivery

    • Peak psychedelic intensity ratings will be measured using Likert scale (0-10 rating scale, 0=not intense at all, 10=highest intensity imaginable)

  4. Psychological Effects

    Time frame: Baseline to 4 weeks after drug delivery

    • Peak psychological effects will be measured by the Altered States of Consciousness (5D-ASC) questionnaire at the end of each dosing session

  5. Psychological Effects

    Time frame: Baseline to 4 weeks after drug delivery

    • Peak psychological effects will be measured by the Challenging Experiences Questionnaire at the end of each dosing session

  6. Psychological Effects

    Time frame: Baseline to 4 weeks after drug delivery

    • Persistent changes in attitude, mood, and behavior will be assessed using Persisting Effects Questionnaire, administered 4 weeks after each dosing session

  7. Psychological Effects

    Time frame: Baseline to 4 weeks after drug delivery

    • Personality profiles will be measured using the Big Five Inventory at baseline and 4 weeks after each dosing session

  8. Adverse Effects

    Time frame: Baseline to 24 hours after dosing session

    • Acute hypertension, hypotension, tachycardia, or bradycardia will be detected through blood pressure and heart rate monitoring at 10 minutes prior to drug administration and measured frequently up to 360 minutes following administration
    • Other dosing-related side effects including descriptive reports of nausea, headaches, dizziness, weakness, drowsiness, paresthesia, or blurred vision will be assessed during check-ins, after dosing effects have waned, and 24 hours following dosing

Sponsors and collaborators

Lead sponsor

University of California, San Francisco

Other

Collaborators

  • Filament Health Corp.

Registry information

Official study title

Comparison of the Effects of PEX20 (Oral Psilocin), PEX30 (Sublingual Psilocin), and PEX10 (Oral Psilocybin) in Healthy Adults

Important dates

Study start
2022
Primary completion
2025
Study completion
2025
First posted
Apr 8, 2022
Registry last updated
Jun 10, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.