This Phase I, randomized, triple-blind, parallel-group trial (n=50) will study the effects of a single 25 mg oral dose of psilocybin versus placebo in healthy adult volunteers aged 21–65, with the primary aim of characterising biological, psychological and high-density EEG (hd-EEG) biomarkers and related safety/tolerability following one-time administration. Participants will be randomised to receive either psilocybin 25 mg (one tablet by mouth) or a matching inactive placebo; the psilocybin is supplied by Filament Health (Burnaby, British Columbia). Key eligibility includes ages 21–65, BMI 18–34 kg/m2, no current or past substance use disorder, limited prior psychedelic exposure (never or at most one prior classic serotonergic psychedelic experience more than 5 years earlier), and contraception/pregnancy requirements for women of childbearing potential. Primary biochemical outcomes measured from baseline to 7 days post-dose include 2 AG (pmol/mL), 2 OG (pmol/mL), AEA (pmol/mL), OEA (pmol/mL), PEA (pmol/mL), Trp (μg/mL), Kyn (ng/mL), Kyn/Trp*1000 and 5 HT (ng/mL); psychological and hd-EEG measures will also be assessed. The study is scheduled to start 2026-09-01 with estimated completion 2029-09-01.
In this study, participants will received either psilocybin (the active ingredient found in certain mushrooms) or an inactive placebo (a look-alike tablet with no active drug). The psilocybin is supplied by Filament Health (Burnaby, British Columbia).
After psilocybin ingestion, the body quickly converts it into psilocin, which is the form that produces the temporary psychological effects. Psilocin mainly works by interacting with serotonin receptors in the brain, especially a type called the 5-HT2A receptor.
This study will be done in healthy volunteers using a single oral dose of 25 mg (one tablet by mouth), consistent with doses used in previous clinical research.
The goal is to understand the biological, psychological, and high-density EEG (hd-EEG) changes that can happen after a one-time dose of psilocybin.
Psilocybin vs Placebo