Role of the Serotonin 2A Receptor in Psilocybin-induced Altered States of Consciousness
Psilocybin (active compound of "magic mushrooms") is a prototypical psychedelic substance that acts via agonism on serotonin (5-HT) 2A receptors. Psilocybin is rapidly metabolized into its active metabolite psilocin. Psilocybin is currently under investigation as potential treatment for various neuropsychiatric disorders. (The sponsor's summary, shortened.)
Eligibility and contacts on ClinicalTrials.govThe registry record
- Status
- Recruiting
- Phase
- Phase 1
- Conditions
- Healthy
- Intervention
- Ketanserin 40mg plus Psilocybin 40mg; 40mg Psilocybin; 20mg Psilocybin; 10mg Psilocybin; 5mg Psilocybin; Placebo
- Sponsor
- University Hospital, Basel, Switzerland
- Ages
- 25 Years to 75 Years
- Sex
- All
- Healthy volunteers
- Accepted
- Enrolment
- 16 people (planned)
- Start
- 21 April 2025
- Primary completion
- August 2026
- Registry last updated
- 28 May 2025
Sites (1)
- Clinical Trial Unit, Basel, Canton of Basel-City, Switzerland (recruiting)
How joining a trial works
- Free to take part
- Trials generally cost participants nothing for the study drug and the study visits, and some pay for travel or time. Check what a study covers on its registry page.
- Screened first
- Every study screens volunteers with questionnaires, medical history and often a physical and psychiatric check. Many people who apply are not enrolled.
- Eligibility is strict
- Common exclusions include a personal or family history of psychosis or bipolar disorder, some heart conditions, pregnancy and certain medications, which you may be asked to stop under medical supervision. Never stop a medication on your own to qualify.
- You may get a placebo
- Many trials compare psilocybin with a placebo or a low dose, and you may not be told which you had until the study ends.
- Contact the study team through the registry
- Each registry record lists the study contacts and sites. We do not republish personal emails or phone numbers; use the link on each trial page.
- Not medical advice
- This is a list of registry records, not a recommendation. Talk to your doctor before applying. Disclaimer · Safety and medications
Source: ClinicalTrials.gov API v2, U.S. National Library of Medicine, read 28 October 2026. Filter: overall status RECRUITING or NOT_YET_RECRUITING; an intervention named psilocybin, psilocin, COMP360 or CYB003. Refreshed weekly; a study's own registry page is always the current record.
Record read from ClinicalTrials.gov API v2, U.S. National Library of Medicine on 28 October 2026. All psilocybin trials