A half-life is how long it takes for a drug’s concentration in blood to halve. In a 2017 study of 12 healthy adults given psilocybin, the mean elimination half-life of psilocin was 3 hours (Brown et al., 2017). A 2025 systematic review reports half-lives of 1.5 to 4 hours across studies (Meshkat et al., 2025).
DMT is far quicker. A 2026 Basel study describes “the short elimination half-life of approximately 6-7 min” after intravenous doses (Erne et al., 2026), and an earlier Basel infusion trial described an early phase of about 5 to 6 minutes followed by a slower late phase (Vogt et al., 2023). The enzyme MAO-A is the main reason (Barker, 2018).
A half-life describes how fast a level falls, not when a test stops finding it or when someone is safe to drive. Some people show a longer tail, which the 2017 authors link to psilocin being released again from its glucuronide (Brown et al., 2017). These are blood measurements; nobody has measured how fast these drugs leave the living human brain.
Sources
- Brown et al., 2017, Clinical Pharmacokinetics
- Meshkat et al., 2025, Pharmaceutics
- Erne et al., 2026, Translational Psychiatry: intravenous DMT
- Vogt et al., 2023, Translational Psychiatry: DMT infusions
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