Healthy Adult ParticipantsEarly Phase 1NCT07910838
Single-dose Effects of Ayahuasca Compared to Esketamine on Experimentally Induced Pain
A Early Phase 1 study testing Ayahuasca and Esketamine 0.2 mg/kg in people with Healthy Adult Participants, run by University of Sao Paulo at 1 site in Brazil.
Trial summary
This was a randomized, parallel, double-blind clinical trial with healthy volunteers Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Adult Participants
- What is being tested?
- Ayahuasca and Esketamine 0.2 mg/kg
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteBrazil
- Study dates
- 1 Jun 2023to 30 Jul 2025
- Phase
- Early 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 18 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- healthy volunteers
Who cannot join
- included history of cardiovascular, liver, or neurological diseases;
- pain disorders and/or reports of chronic or acute pain (self-reported);
- a score >10 on the Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) scales;
- any psychiatric diagnosis evaluated through the International Neuropsychiatric Interview (M.I.N.I; DSM-V);
- pregnant or breastfeeding women;
- previous experience (> 2 lifetime uses) with ayahuasca;
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- use of psychoactive medications (antidepressants, mood stabilizers, anxiolytics, and antipsychotics);
- use of other drugs (psychostimulants, maximum of 20 lifetime uses; hallucinogens, maximum of 10 lifetime uses).
- In addition, participants could not have experienced any kind of pain in the last seven days, as identified through a pre-existing pain condition checklist questionnaire. -
Trial locations and contacts
1 site in 1 country.
Brazil1 site
Hospital das Clínicas da FMRP-USP
Ribeirão Preto, São Paulo, 1421360
About this study
Official title: Single-dose Effects of Ayahuasca Compared to Esketamine on Experimentally Induced Pain: a Randomized, Double-blind Study
This was a randomized, parallel, double-blind clinical trial with healthy volunteers
- Conditions
- Healthy Adult Participants
- Being tested
- Ayahuasca, Esketamine 0.2 mg/kg
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AyahuascaDrug
ayahuasca
Esketamine 0.2 mg/kgDrug
active comparator
| Study group | Role | What they receive |
|---|---|---|
| Ayahuasca | Experimental | experimental Receives: Drug: Ayahuasca |
| esketamine | Active comparator | Not described Receives: Drug: Esketamine 0.2 mg/kg |
What is being measured
The primary outcome is the main question the study is designed to answer.
Subjective pain
Pain intensity measured with a visual analogue scale (pain visual analogue scale with scores ranging from 0 to 10, where higher scores mean more pain)
Measured: 0 to 4 hours post-drug
Pain tolerance
Pain tolerance measured in Celcius
Measured: 0 to 4 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Nov 2026
- Study start1 Jun 2023
- Primary completion30 Jul 2025
- Study completion30 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy Adult ParticipantsStudies of the same condition, open and under way.
- More trials run by University of Sao PauloThe 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
- Early Phase 1
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Sao Paulo
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rafael Guimarães dos Santos, University of Sao Paulo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07910838
- Sponsor's protocol ID
- 69291023500005440
- Status last verified
- Oct 2026
- First submitted
- 14 Oct 2026
- Last updated
- 2 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Single-dose Effects of Ayahuasca Compared to Esketamine on Experimentally Induced Pain: a Randomized, Double-blind Study
- ClinicalTrials.gov ID
- NCT07910838
- Acronym / sponsor ID
- 69291023500005440
- Conditions
- Healthy Adult Participants
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- University of Sao PauloUniversity, hospital or other
- Study start
- 1 Jun 2023 (actual)
- Primary completion
- 30 Jul 2025 (actual)
- Study completion
- 30 Jul 2025 (actual)
- First posted
- 2 Nov 2026 (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.
This was a randomized, parallel, double-blind clinical trial with healthy volunteers
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Ayahuasca | Experimental | Drug: Ayahuascaexperimental |
| esketamine | Active comparator | Drug: Esketamine 0.2 mg/kg |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- healthy volunteers
Key exclusion criteria (9 listed)
- included history of cardiovascular, liver, or neurological diseases;
- pain disorders and/or reports of chronic or acute pain (self-reported);
- a score >10 on the Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) scales;
- any psychiatric diagnosis evaluated through the International Neuropsychiatric Interview (M.I.N.I; DSM-V);
- pregnant or breastfeeding women;
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 |
|---|---|---|
| Ayahuascaayahuasca | Drug | Ayahuasca |
| Esketamine 0.2 mg/kgactive comparator | Drug | esketamine |
Primary outcome
Subjective pain
Time frame: 0 to 4 hours post-drug
Pain intensity measured with a visual analogue scale (pain visual analogue scale with scores ranging from 0 to 10, where higher scores mean more pain)
Pain tolerance
Time frame: 0 to 4 hours
Pain tolerance measured in Celcius
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Nov 2026.
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Ayahuasca and Esketamine 0.2 mg/kg in people with Healthy Adult Participants, run by University of Sao Paulo at 1 site in Brazil.
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 1 inclusion and 9 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: finished, as of the sponsor's last update on 2 Nov 2026. 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 Brazil. 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?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Subjective pain (time frame: 0 to 4 hours post-drug). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 2 Nov 2026.