A Phase 1 single ascending dose study of pure oral harmine in healthy volunteers.
Journal of psychopharmacology (Oxford, England) October 1, 2024 Jessica L Ables, Leah Israel, Olivia Wood et al. 17 citations
Harmine, a component of the hallucinogenic brew ayahuasca, was tested in a phase 1 clinical trial to determine its safety, tolerability, and psychoactive effects when taken alone. Twenty-five healthy adults received single oral doses of 100 to 500 mg of pharmaceutical-grade harmine hydrochloride. The maximum tolerated dose was between 100 and 200 mg, and doses above 2.7 mg/kg caused vomiting, drowsiness, and limited psychoactive effects in 90% of participants. No serious adverse events occurred. Harmine alone can be safely administered at low doses, but higher doses produce dose-limiting side effects and only mild psychoactivity.