Safety and clinical effects of psychedelics across different use patterns

In adults receiving one to three supervised doses of psychedelics, common side effects include transient headache, nausea, anxiety, and cardiovascular activation.

• Serious reactions to psychedelics are uncommon but can include persistent anxiety and suicidality signals.
• MDMA-assisted therapy has shown evidence for effectiveness in treating post-traumatic stress disorder.
• Psilocybin-based interventions are associated with improvements in depression outcomes.
• Naturalistic studies indicate that individual vulnerability and context may influence psychedelic effects, though frequency of use is often poorly measured.
• Short-term microdosing trials demonstrate limited benefits, while long-term safety regarding cardiac and psychiatric health remains uncertain.
• Priorities for future research include exposure-defined cohorts and blinding-aware comparative trials.

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