HealthyPhase 1NCT05317689
Comparing the Effects of Psilocin and Psilocybin in Healthy Adults
A Phase 1 study testing Psilocin, Psilocybin and Sublingual Psilocin in people with Healthy, run by University of California, San Francisco at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 25 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Psilocin, Psilocybin and Sublingual Psilocin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 26 May 2022to Jul 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
United States1 site
University of California, San Francisco
San Francisco, California, 94143
About this study
Official title: Comparison of the Effects of PEX20 (Oral Psilocin), PEX30 (Sublingual Psilocin), and PEX10 (Oral 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.
Read the detailed description
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.
- Conditions
- Healthy
- Being tested
- Psilocin, Psilocybin, Sublingual Psilocin
- Keywords
- Psilocybin, Psilocin, Psilocybin Therapy, Psychedelics, Healthy, San Francisco
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PsilocinDrug
17.5mg oral psilocin with psychological support and physiological monitoring
PsilocybinDrug
25mg oral psilocybin with psychological support and physiological monitoring
Sublingual PsilocinDrug
2.18mg - 4.36mg sublingual psilocin with psychological support and physiological monitoring
| Study group | Role | What they receive |
|---|---|---|
| Oral & Sublingual Psilocin, & Oral Psilocybin | Active comparator | Every participant will be administered Oral Psilocin, Sublingual Psilocin, and oral psilocybin in a randomized order. Receives: Drug: Psilocin; Drug: Psilocybin; Drug: Sublingual Psilocin |
| Sublingual Psilocin | Active comparator | Depending on a number of factors, participants may complete a fourth session where they receive sublingual psilocin for the second time. Receives: Drug: Sublingual Psilocin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Physiological Effects
blood pressure
Measured: Baseline to 8 hours following drug delivery
Physiological Effects
heart rate
Measured: Baseline to 8 hours following drug delivery
Psychological Effects
- Peak psychedelic intensity ratings will be measured using Likert scale (0-10 rating scale, 0=not intense at all, 10=highest intensity imaginable)
Measured: Baseline to 4 weeks after drug delivery
Psychological Effects
- Peak psychological effects will be measured by the Altered States of Consciousness (5D-ASC) questionnaire at the end of each dosing session
Measured: Baseline to 4 weeks after drug delivery
Psychological Effects
- Peak psychological effects will be measured by the Challenging Experiences Questionnaire at the end of each dosing session
Measured: Baseline to 4 weeks after drug delivery
Psychological Effects
- Persistent changes in attitude, mood, and behavior will be assessed using Persisting Effects Questionnaire, administered 4 weeks after each dosing session
Measured: Baseline to 4 weeks after drug delivery
Psychological Effects
- Personality profiles will be measured using the Big Five Inventory at baseline and 4 weeks after each dosing session
Measured: Baseline to 4 weeks after drug delivery
Adverse Effects
- 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
Measured: Baseline to 24 hours after dosing session
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Apr 2022
- Study start26 May 2022
- Primary completion16 Jan 2025
- Study completionJul 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by University of California, San FranciscoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Collaborators
- Filament Health Corp.
- Responsible party
- Principal investigator, Joshua Woolley, MD, PhD, University of California, San Francisco
- Investigators
- Joshua Woolley, MD/PhD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05317689
- Sponsor's protocol ID
- IRB#21-33765
- Other IDs
- PR#202143H, 156917
- Status last verified
- Sep 2024
- First submitted
- 7 Mar 2022
- Last updated
- 10 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Bogenschutz MP, Johnson MW. Classic hallucinogens in the treatment of addictions. Prog Neuropsychopharmacol Biol Psychiatry. 2016 Jan 4;64:250-8. doi: 10.1016/j.pnpbp.2015.03.002. Epub 2015 Mar 14.
PubMed 25784600Benet-Martinez V, John OP. Los Cinco Grandes across cultures and ethnic groups: multitrait multimethod analyses of the Big Five in Spanish and English. J Pers Soc Psychol. 1998 Sep;75(3):729-50. doi: 10.1037//0022-3514.75.3.729.
PubMed 9781409Brown RT, Nicholas CR, Cozzi NV, Gassman MC, Cooper KM, Muller D, Thomas CD, Hetzel SJ, Henriquez KM, Ribaudo AS, Hutson PR. Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults. Clin Pharmacokinet. 2017 Dec;56(12):1543-1554. doi: 10.1007/s40262-017-0540-6.
PubMed 28353056Barrett FS, Bradstreet MP, Leoutsakos JS, Johnson MW, Griffiths RR. The Challenging Experience Questionnaire: Characterization of challenging experiences with psilocybin mushrooms. J Psychopharmacol. 2016 Dec;30(12):1279-1295. doi: 10.1177/0269881116678781. Epub 2016 Nov 17.
PubMed 27856683Anderson BT, Danforth A, Daroff PR, Stauffer C, Ekman E, Agin-Liebes G, Trope A, Boden MT, Dilley PJ, Mitchell J, Woolley J. Psilocybin-assisted group therapy for demoralized older long-term AIDS survivor men: An open-label safety and feasibility pilot study. EClinicalMedicine. 2020 Sep 24;27:100538. doi: 10.1016/j.eclinm.2020.100538. eCollection 2020 Oct.
PubMed 33150319Tai ML, Szigeti B, Downey AE, Aday JS, Fredenburg L, Sakai K, Molina C, Fernandes-Osterhold G, Bradley ER, Pantoni M, Moss R, Lightburn B, Plessow F, O'Donovan A, Woolley JD. A randomized crossover trial comparing the acute physiological and psychological effects of botanical formulations of oral psilocybin, oral psilocin, and sublingual psilocin. J Psychopharmacol. 2026 Aug 29:2698811261478603. doi: 10.1177/02698811261478603. Online ahead of print.
PubMed 42668404
Study at a glance
From the registry record, last updated by the sponsor on 10 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of the Effects of PEX20 (Oral Psilocin), PEX30 (Sublingual Psilocin), and PEX10 (Oral Psilocybin) in Healthy Adults
- ClinicalTrials.gov ID
- NCT05317689
- Acronym / sponsor ID
- IRB#21-33765
- Conditions
- Healthy
- Keywords
- Psilocybin, Psilocin, Psilocybin Therapy, Psychedelics, Healthy, San Francisco
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of California, San FranciscoUniversity, hospital or other
- Collaborators
- Filament Health Corp.
- Study start
- 26 May 2022 (actual)
- Primary completion
- 16 Jan 2025 (actual)
- Study completion
- Jul 2025 (estimated)
- First posted
- 8 Apr 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Oral & Sublingual Psilocin, & Oral Psilocybin | Active comparator | Drug: Psilocin, Drug: Psilocybin, Drug: Sublingual PsilocinEvery participant will be administered Oral Psilocin, Sublingual Psilocin, and oral psilocybin in a randomized order. |
| Sublingual Psilocin | Active comparator | Drug: Sublingual PsilocinDepending on a number of factors, participants may complete a fourth session where they receive sublingual psilocin for the second time. |
Who may qualify
- Ages
- 25 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- 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
Key exclusion criteria (3 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Psilocin17.5mg oral psilocin with psychological support and physiological monitoring | Drug | Oral & Sublingual Psilocin, & Oral Psilocybin |
| Psilocybin25mg oral psilocybin with psychological support and physiological monitoring | Drug | Oral & Sublingual Psilocin, & Oral Psilocybin |
| Sublingual Psilocin2.18mg - 4.36mg sublingual psilocin with psychological support and physiological monitoring | Drug | Oral & Sublingual Psilocin, & Oral Psilocybin, Sublingual Psilocin |
Primary outcome
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
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jun 2025.
- Background: PubMed 25784600Bogenschutz MP, Johnson MW. Classic hallucinogens in the treatment of addictions. Prog Neuropsychopharmacol Biol Psychiatry. 2016 Jan 4;64:250-8. doi: 10.1016/j.pnpbp.2015.03.002. Epub 2015 Mar 14.
- Background: PubMed 9781409Benet-Martinez V, John OP. Los Cinco Grandes across cultures and ethnic groups: multitrait multimethod analyses of the Big Five in Spanish and English. J Pers Soc Psychol. 1998 Sep;75(3):729-50. doi: 10.1037//0022-3514.75.3.729.
- Background: PubMed 28353056Brown RT, Nicholas CR, Cozzi NV, Gassman MC, Cooper KM, Muller D, Thomas CD, Hetzel SJ, Henriquez KM, Ribaudo AS, Hutson PR. Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults. Clin Pharmacokinet. 2017 Dec;56(12):1543-1554. doi: 10.1007/s40262-017-0540-6.
- Background: PubMed 27856683Barrett FS, Bradstreet MP, Leoutsakos JS, Johnson MW, Griffiths RR. The Challenging Experience Questionnaire: Characterization of challenging experiences with psilocybin mushrooms. J Psychopharmacol. 2016 Dec;30(12):1279-1295. doi: 10.1177/0269881116678781. Epub 2016 Nov 17.
- Background: PubMed 33150319Anderson BT, Danforth A, Daroff PR, Stauffer C, Ekman E, Agin-Liebes G, Trope A, Boden MT, Dilley PJ, Mitchell J, Woolley J. Psilocybin-assisted group therapy for demoralized older long-term AIDS survivor men: An open-label safety and feasibility pilot study. EClinicalMedicine. 2020 Sep 24;27:100538. doi: 10.1016/j.eclinm.2020.100538. eCollection 2020 Oct.
- Derived from this study: PubMed 42668404Tai ML, Szigeti B, Downey AE, Aday JS, Fredenburg L, Sakai K, Molina C, Fernandes-Osterhold G, Bradley ER, Pantoni M, Moss R, Lightburn B, Plessow F, O'Donovan A, Woolley JD. A randomized crossover trial comparing the acute physiological and psychological effects of botanical formulations of oral psilocybin, oral psilocin, and sublingual psilocin. J Psychopharmacol. 2026 Aug 29:2698811261478603. doi: 10.1177/02698811261478603. Online ahead of print.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Joshua Woolley, MD/PhD principal investigator
University of California, San Francisco
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Psilocin, Psilocybin and Sublingual Psilocin in people with Healthy, run by University of California, San Francisco at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 10 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Physiological Effects (time frame: Baseline to 8 hours following drug delivery). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05317689, which also lists 6 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Jun 2025.