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)
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.