Scientists probe the Brain's 'Mystical' switch during psilocybin trips
NCT ID NCT07565493
First seen Jun 27, 2026 · Last updated Sep 15, 2026 · Updated 3 times
Summary
This early-stage study at Johns Hopkins University is testing how blocking a specific brain receptor (5-HT1a) alters the effects of psilocybin, the active ingredient in magic mushrooms. Eighteen healthy volunteers will receive psilocybin with either pindolol (a receptor blocker) or a placebo, and researchers will measure their subjective experiences and brain activity using EEG. The goal is to better understand the biological mechanisms behind the psychedelic experience, not to treat any disease.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Psilocybin and pindolol
- What this could lead to
- If successful, this study could help scientists understand how psilocybin produces its mind-altering effects, potentially guiding future therapies for mental health conditions.
- What could go wrong
- This is a very small, early-phase study in healthy volunteers, not patients. It is designed to measure brain activity and subjective experiences, not to test a treatment. Results may not translate to clinical benefits.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Early phase 1
The earliest testing in people: a first look at safety, in a very small group.
- Participants
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About 18 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Aug 2026
- Expected to finish
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Jun 2028
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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21 to 60 years
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion criteria: * 21 - 60 years old * Must give written or electronic informed consent * Must have at least a high-school level of education or equivalent (e.g. GED) and are fluent in English * Must be healthy and psychologically stable as determined by screening for medical and psychiatric problems via a personal interview, a medical questionnaire, a physical examination, an electrocardiogram (ECG), and routine medical blood and urinalysis laboratory tests * Must agree not to take any as needed (PRN) medications on the mornings of drug sessions * Must agree not to take sildenafil (Viagra®), tadalafil, or similar medications within 72 hours of each drug administration. * Must agree to refrain from using all psychoactive substances within 24 hours or 5 elimination half-lives (whichever is greater) before psilocybin administration. Caffeine is the exception. * Must have a negative urine toxicology report on the same day as drug dosing. * Who are female and of child-bearing potential and are sexually active, must agree to use highly effective means of birth control (i.e. implants, injectables, combined oral contraceptives, progestin-containing intrauterine device (IUD) or vasectomized partner) for the duration of this study. * Who are male and sexually active, must agree to use contraception and refrain from sperm donation within 90 days of completing dosing sessions. Effective methods of contraception are barrier, hormonal, and sterilization methods. Exclusion Criteria: * Are currently taking a medication with any significant pharmacokinetic or pharmacodynamic interactions with pindolol (e.g. beta-blockers or other anti-hypertensive medications). * Have a history of orthostatic hypotension or low blood-pressure. * Have elevated transaminases (2x the upper limit of normal) * Have a Child-Pugh score that falls within classes B or C. * Are pregnant (as indicated by a positive urine pregnancy test assessed at intake and before each drug session) or nursing. * Have cardiovascular conditions: coronary artery disease, stroke, angina, uncontrolled hypertension, a clinically significant ECG abnormality (e.g. atrial fibrillation, corrected QT interval (QTc) \> 450 msec), artificial heart valve, symptomatic valvopathy, history of pulmonary hypertension or transient ischemic attack (TIA) in the past year; systolic blood pressure \> 139, diastolic blood pressure \> 89 * Have epilepsy or a history of seizures * Have insulin-dependent diabetes; if taking oral hypoglycemic agent, then no history of hypoglycemia * Are currently taking on a regular (e.g. daily) basis any medications having a centrally acting serotonergic effect, including monoamine oxidase inhibitors (MAOIs). For individuals who have intermittent or PRN use of such medications, psilocybin sessions will not be conducted until at least five half-lives of the agent have elapsed after the last dose. * Have a current diagnosis of schizophrenia spectrum disorders * Have a current diagnosis of bipolar spectrum disorders * Have a current diagnosis of major depressive disorder or Generalized Anxiety Disorder * Have a current diagnosis or history of substance induced psychotic disorder * Have a current DSM-5 moderate or severe alcohol or drug use disorder (excluding caffeine and nicotine) * Have a first degree relative with bipolar I disorder, or schizophrenia spectrum disorder. * Have a psychiatric condition judged to be incompatible with establishment of safe exposure to psilocybin. * Have a BMI ≥ 40 * Report a known history of sleep apnea, symptoms indicative of sleep apnea, or have an Apnea-Hypopnea Index (AHI) \> 15, or STOP BANG \>5 * Taking prescribed hypnotics or other medications known to alter sleep physiology: i.e., Z-drugs, Benzodiazepines, Orexin Agonists or Antagonist, Beta Blockers. * Regularly taking over-the-counter sleep aids (inc. melatonin and diphenhydramine) and unwilling to abstain during the study. * Insomnia Severity Index ≥ 10
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As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
1 site. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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Center for Psychedelics and Consciousness Research
RECRUITINGBaltimore, Maryland, 21224-5010, United States
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