Comparing the Effects of Psilocin and Psilocybin in Healthy Adults
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ClinicalTrials.gov Identifier: NCT05317689 |
Recruitment Status :
Recruiting
First Posted : April 8, 2022
Last Update Posted : June 8, 2022
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Condition or disease | Intervention/treatment | Phase |
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Healthy | Drug: Psilocin Drug: Psilocybin Drug: Sublingual Psilocin | Phase 1 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 20 participants |
Allocation: | Randomized |
Intervention Model: | Crossover Assignment |
Masking: | Triple (Participant, Investigator, Outcomes Assessor) |
Primary Purpose: | Other |
Official Title: | Comparison of the Effects of PEX20 (Oral Psilocin), PEX30 (Sublingual Psilocin), and PEX10 (Oral Psilocybin) in Healthy Adults |
Actual Study Start Date : | May 26, 2022 |
Estimated Primary Completion Date : | December 2024 |
Estimated Study Completion Date : | December 2024 |
Arm | Intervention/treatment |
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Active Comparator: Oral & Sublingual Psilocin, & Oral Psilocybin
Every participant will be administered Oral Psilocin, Sublingual Psilocin, and oral psilocybin in a randomized order.
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Drug: Psilocin
17.5mg oral psilocin with psychological support and physiological monitoring Drug: Psilocybin 25mg oral psilocybin with psychological support and physiological monitoring Drug: Sublingual Psilocin 2.18mg - 4.36mg sublingual psilocin with psychological support and physiological monitoring |
Active Comparator: Sublingual Psilocin
Depending on a number of factors, participants may complete a fourth session where they receive sublingual psilocin for the second time.
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Drug: Sublingual Psilocin
2.18mg - 4.36mg sublingual psilocin with psychological support and physiological monitoring |
- Physiological Effects [ Time Frame: Baseline to 8 hours following drug delivery ]blood pressure
- Physiological Effects [ Time Frame: Baseline to 8 hours following drug delivery ]heart rate
- 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)
- 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
- 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
- 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
- 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
- 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

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Ages Eligible for Study: | 25 Years to 50 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
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

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05317689
Contact: Jacob Aday | 415-221-4810 ext 24117 | psilocybinstudies@ucsf.edu |
United States, California | |
University of California, San Francisco | Recruiting |
San Francisco, California, United States, 94143 | |
Contact: Jake Aday 415-942-0820 | |
Contact: Josh Woolley 415-221-4810 ext 24117 |
Principal Investigator: | Joshua Woolley | University of California, San Francisco | |
Study Chair: | Jacob Aday | University of California, San Francisco |
Documents provided by Joshua Woolley, MD/PhD, University of California, San Francisco:
Responsible Party: | Joshua Woolley, MD/PhD, Associate Professor, Psychiatry, University of California, San Francisco |
ClinicalTrials.gov Identifier: | NCT05317689 |
Other Study ID Numbers: |
IRB#21-33765 PR#202143H ( Other Identifier: Research Advisory Panel - California ) 156917 ( Other Identifier: FDA ) |
First Posted: | April 8, 2022 Key Record Dates |
Last Update Posted: | June 8, 2022 |
Last Verified: | June 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Psilocybin Psilocin Psilocybin Therapy |
Psychedelics Healthy San Francisco |
Psilocybin Psilocin Hallucinogens Physiological Effects of Drugs Psychotropic Drugs |