Role of the Serotonin 5-HT2A Receptor in Mescaline-induced Altered States of Consciousness

The present MDR-study will characterize the subjective effects of different doses of mescaline using modern psychometric instruments and examine the contribution of the 5-HT2A receptor in the mescaline-induced alterations of consciousness.

Topic Healthy Subjects
Compound Placebo Mescaline
Country Switzerland
Visit trial
Status Not yet recruiting
Results Published
Start date 05 January 2021
End date 01 January 2023
Chance of happening 90%
Phase Phase I
Design Blinded
Type Interventional
Generation First
Participants 16
Sex All
Age 25- 65
Therapy No

Trial Details

Mescaline (the active substance in Peyote and San Pedro cacti) is a classic and long known serotonergic psychedelic substance (hallucinogen) that is widely used for recreational, spiritual, and/or ethno medical purposes. Despite its long history, modern data on the acute effects of mescaline on human is lacking. Mescaline produces prototypical psychedelic effects, similar as lysergic acid diethylamide (LSD) and psilocybin. The serotonin 2A (5-HT2A) receptor is thought to primarily mediate acute alterations of consciousness induced by LSD and psilocybin. However, the contributory role of the 5-HT2A receptor in mescaline-induced alterations of consciousness is unclear. Using 5-HT2A receptor antagonist ketanserin, the psychedelic experience induced by LSD and psilocybin can be attenuated and shortened. The present study therefore explores the role the 5-HT2A receptor in mescaline-induced altered states of consciousness using escalating doses of mescaline and the 5-HT2A receptor blocker ketanserin administered before a high dose of mescaline. Objective: The present MDR-study will characterize the subjective effects of different doses of mescaline using modern psychometric instruments and examine the contribution of the 5-HT2A receptor in the mescaline-induced alterations of consciousness. Design: Double-blind, placebo-controlled, 6-period cross-over design with six treatment conditions. 1) Placebo (Pla + Pla), 2) 100 mg mescaline (Pla + 100mg mescaline), 3) 200 mg mescaline (Pla + 200mg mescaline), 4) 400 mg mescaline (Pla + 400mg mescaline), 5) 800 mg mescaline (Pla + 800mg mescaline), and 6) 40mg ketanserin and 800mg mescaline (Ket + 800mg mescaline). Participants: 16 healthy participants aged ≥ 25 and ≤ 65 years (8 female, 8 male)

NCT Number NCT04849013

Sponsors & Collaborators

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

MindMed
MindMed is one of the largest companies in the psychedelics space and is developing various psychedelics for mental health disorders.

Heffter Research Institute
The Heffter Research Institute has been advancing psychedelics (psilocybin) as medicines since 1993.

Papers

Acute dose-dependent effects of mescaline in a double-blind placebo-controlled study in healthy subjects
This randomized, double-blind, placebo-controlled, crossover study (n=16) investigates the dose-dependent acute effects, pharmacokinetics, and mechanism of action of mescaline (100-800mg; 5x) in healthy subjects. It finds that mescaline induces dose-dependent subjective effects, increases blood pressure and heart rate, and has dose-proportional pharmacokinetics, with effects primarily mediated by 5-HT2A receptors as demonstrated by ketanserin co-administration.

Data attribution

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