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Safety pharmacology of acute psilocybin administration in healthy participants

Isabelle Straumann, Friederike Holze, Laura Ley, Nepomuk Halter, Anna M Becker, Matthias E. Liechti

Neuroscience Applied 2024 DOI: 10.1016/j.nsa.2024.104060 (opens in new tab)

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Study at a glance

AI-extracted from the abstract
Characteristics Pooled analysis of randomized crossover studies Peer reviewed
Sample size 85
Population Healthy participants
Intervention Psilocybin dihydrate
Dose 15 mg, 20 mg, 25 mg, 30 mg
Topics Anxiety Psilocybin
Keywords Heart rate Adverse effect Hallucinogen Crossover study Anesthesia Safety pharmacology Drug
Citations 24
Key points Single doses of psilocybin up to 30 mg are safe in healthy participants under controlled conditions, with no serious adverse reactions and only moderate autonomic effects.

Abstract

Psilocybin is being studied for its therapeutic potential in various mental health disorders, such as depression, anxiety, and addiction. Initial studies suggested that psilocybin is generally safe when used under controlled conditions, but more research is needed to better understand its safety profile. We report safety pharmacology data from a pooled analysis of three randomized crossover studies that included 85 healthy participants and 113 single-dose administrations of psilocybin. Single oral doses included 15 mg, 20 mg, 25 mg, and 30 mg psilocybin dihydrate. We investigated subjective effects, blood pressure, heart rate, body temperature, acute and subacute adverse effects, reports of flashbacks, and liver and kidney function before and after the studies. The 20, 25, and 30 mg doses of psilocybin produced stronger effects than the 15 mg dose. Psilocybin at all doses induced higher "good drug effects" than "bad drug effects." Only the 25 and 30 mg doses increased anxiety. Psilocybin elevated autonomic effects only moderately. Tachycardia (>100 beats/min) was observed with 7% of all psilocybin administrations. Body temperature >38° was reached in 7%, 9%, 17%, and 32% of the participants with the 15, 20, 25, and 30 mg doses, respectively. Kidney and liver function parameters were unaltered at the end of the study. Five participants (6%) reported transient flashback phenomena. No serious adverse reactions occurred. These findings suggest that a single administration of psilocybin is safe with regard to acute psychological and physical harm in healthy participants in a controlled research setting.

Comparable studies

Other randomized controlled trials on psilocybin for anxiety, most cited first.

Study Year Design Participants
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial Cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety 2016 Randomized controlled trial n = 51
Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial Patients with cancer-related anxiety and depression 2016 Double-blind, placebo-controlled, crossover trial n = 29
Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance Hallucinogen-naïve adults reporting regular participation in religious or spiritual... 2006 Double-blind study n = 36
Pilot Study of Psilocybin Treatment for Anxiety in Patients With Advanced-Stage Cancer Adults with advanced-stage cancer and anxiety 2010 Double-blind, placebo-controlled study n = 12
Acute, subacute and long-term subjective effects of psilocybin in healthy humans: a pooled analysis of experimental studies Healthy human subjects 2010 Pooled analysis of double-blind placebo-controlled experimental studies n = 110

Citations in the library

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