Acute Effects of MDMA Co-administration on the Response to Psilocybin in Healthy Subjects (MDMA-Psilo)

This double-blind, placebo-controlled, crossover trial (n=24) will investigate the acute effects of psilocybin (20mg) when co-administered with MDMA (100mg) in healthy adults.

The study, conducted by University Hospital Basel in Switzerland, aims to determine whether MDMA enhances the positive effects of psilocybin—such as mood elevation, empathy, and trust—while reducing potential negative effects like anxiety and paranoia.

Participants will take part in four different sessions, receiving either psilocybin alone, MDMA alone, both substances together, or a placebo. The study will measure subjective experiences using various psychological scales, as well as physiological responses such as heart rate, blood pressure, and body temperature. Researchers will also assess blood plasma levels of both drugs and their metabolites. This Phase I study, led by Professor Dr. Matthias Liechti, is expected to run from April 2025 to July 2026.

Topic Healthy Subjects
Compound Psilocybin MDMA Placebo
Country Switzerland
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Trial Details



Trial Number

Sponsors & Collaborators

University of Basel
The University of Basel Department of Biomedicine hosts the Liechti Lab research group, headed by Matthias Liechti.

Data attribution

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