Dextromethorphan Beyond the Cough: Exploring Its Psychedelic Potential: A Systematic Review
CNS Drugs June 15, 2026 Edward P. Hackett, Aditi Chaudhri -, Linda Hasman et al.
Dextromethorphan (DXM), a common over-the-counter cough suppressant, produces psychedelic effects at high doses that may be useful for treating psychiatric disorders resistant to standard therapies. A systematic review of eight studies with 104 total participants found that psychedelic effects begin at 100 mg, with hallucinatory and mystical experiences intensifying at 300 and 400 mg. Adverse effects such as nausea, vomiting, motor impairment, and cognitive slowing become more prominent above 200 mg. The evidence is too limited to establish true dose-response relationships, and the certainty of evidence is low for most outcomes, highlighting the need for larger, well-designed studies.