Klemens Egger - The Consciousness Library

Global increases in brain glucose metabolism following acute N,N-dimethyltryptamine and harmine administration in healthy volunteers: A randomised [18F]FDG-PET study.

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism June 1, 2026 Klemens Egger, Robert Bozsak, Helena Aicher et al.

Classical psychedelics such as N,N-dimethyltryptamine (DMT) modulate consciousness via serotonergic receptor agonism, and are increasingly investigated for their psychotherapeutic potential. When combined with the monoamine oxidase A (MAO-A) inhibitor harmine-mimicking the pharmacological profile of ayahuasca-oral DMT induces a psychedelic experience lasting 4-5 h. While some neuroimaging...

DOI: 10.1177/0271678x261454172 Full text DMT Fdg-PET Glucose metabolism Harmine +2

Global increases in brain glucose metabolism following acute N,N-dimethyltryptamine and harmine administration in healthy volunteers: A randomised [ 18 F]FDG-PET study

Universität Zürich, ZORA June 1, 2026 Klemens Egger, Robert Bozsak, Helena Aicher et al.

Classical psychedelics such as N,N -dimethyltryptamine (DMT) modulate consciousness via serotonergic receptor agonism, and are increasingly investigated for their psychotherapeutic potential. When combined with the monoamine oxidase A (MAO-A) inhibitor harmine—mimicking the pharmacological profile of ayahuasca—oral DMT induces a psychedelic experience lasting 4–5 h. While some neuroimaging...

DOI: 10.5167/uzh-434709 Harmine Placebo Neuroimaging Metabolite +9

Global increases in brain glucose metabolism following acute N,N-dimethyltryptamine and harmine administration in healthy volunteers: A randomised [¹⁸F]FDG-PET study

Repository for Publications and Research Data (ETH Zurich) 2026 Klemens Egger, Robert Bozsak, Helena Aicher et al.

Classical psychedelics such as N,N-dimethyltryptamine (DMT) modulate consciousness via serotonergic receptor agonism, and are increasingly investigated for their psychotherapeutic potential. When combined with the monoamine oxidase A (MAO-A) inhibitor harmine—mimicking the pharmacological profile of ayahuasca—oral DMT induces a psychedelic experience lasting 4–5 h. While some neuroimaging...

DOI: 10.3929/ethz-c-000801722 Harmine Placebo Neuroimaging Metabolite +9

Meditation, psychedelics, and brain connectivity: A randomized controlled resting-state fMRI study of N,N-dimethyltryptamine and harmine in a meditation retreat.

Imaging Neurosci (Camb) September 29, 2025 Klemens Egger, Daniel Meling, Firuze Polat et al. 1 citation

Meditation, psychedelics, and brain connectivity: A randomized controlled resting-state fMRI study of N,N-dimethyltryptamine and harmine in a meditation retreat.

DOI: 10.1162/imag.a.907 Full text N-dimethyltryptamine Neuroplasticity Meditation Mindfulness +17

Meditation, psychedelics, and brain connectivity: A randomized controlled resting-state fMRI study of N,N-dimethyltryptamine and harmine in a meditation retreat

Universität Zürich, ZORA September 29, 2025 Klemens Egger, Daniel Meling, Firuze Polat et al.

Both meditation and psychedelics are widely studied for their therapeutic potential in mental health. Recent research suggests potential synergies between mindfulness practice and psychedelics, though empirical studies have primarily focused on psilocybin. This study investigates the distinct and combined effects of mindfulness practice and an ayahuasca-inspired formulation containing...

DOI: 10.5167/uzh-280470 Meditation Mindfulness Default mode network Placebo +6

Global Increases in Brain Glucose Metabolism Following Acute N,N-Dimethyltryptamine and Harmine Administration in Healthy Volunteers: An [¹⁸F]FDG-PET Study

Research Square July 27, 2025 Klemens Egger, Robert Bozsak, Helena Aicher et al. 1 citation

Global Increases in Brain Glucose Metabolism Following Acute N,N-Dimethyltryptamine and Harmine Administration in Healthy Volunteers: An [¹⁸F]FDG-PET Study

DOI: 10.21203/rs.3.rs-7099164/v1 N-dimethyltryptamine Psychoactive compounds n Harmine Brain activity +6

Population pharmacokinetic-pharmacodynamic modeling of co-administered N,N-dimethyltryptamine and harmine in healthy subjects.

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie July 9, 2025 Angela Äbelö, John W Smallridge, Robin von Rotz et al. 3 citations

N,N-dimethyltryptamine (DMT) is a psychedelic compound commonly co-administered with the monoamine oxidase inhibitor harmine in ayahuasca-inspired formulations. However, the impact of harmine on DMT pharmacokinetics (PK) and pharmacodynamics (PD) remains insufficiently characterized. In this single-blind, randomized, two-arm, factorial, dose-finding study, 16 healthy participants (9 males, 7...

DOI: 10.1016/j.biopha.2025.118329 Full text Pharmacodynamics Pharmacokinetics Psychedelics Harmine-DMT Interaction Alter +10

Neurobehavioral and Molecular Pharmacology of Pharmahuasca ($\textit{N,N}$-dimethyltryptamine (DMT) and Harmine) in Humans – A Combined Neuropharmacological and Brain Imaging Approach

June 4, 2025 Klemens Egger

Over the past decade, research with psychedelics has gained new momentum, leading to a psychedelic renaissance in both basic and clinical research. Among these substances is ayahuasca, an Amazonian plant medicine used for millennia by indigenous people for ritualistic and healing practices, which has recently entered research labs in the Americas and Europe. Preliminary findings indicate its...

DOI: 10.5167/uzh-278132 Full text Neuroplasticity Psychedelic medicine Mental health treatment Brain imaging

Examining the pharmacokinetic and pharmacodynamic interaction of N,N-dimethyltryptamine and harmine in healthy volunteers: Α factorial dose-escalation study.

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie March 1, 2025 Klemens Egger, Javier Jareño Redondo, Jovin Müller et al. 14 citations

Ayahuasca, a traditional psychoactive Amazonian brew, usually contains N,N-dimethyltryptamine (DMT) and β-carboline (harmine, harmaline, tetrahydroharmine) monoamine oxidase inhibitors. However, the pharmacological interactions between these compounds remain incompletely understood. In this study, we developed an ayahuasca-inspired formulation containing DMT and harmine, aiming to...

DOI: 10.1016/j.biopha.2025.117908 Full text DMT Ayahuasca pharmahuasca Harmine Pharmacokinetics +5

Molecular brain imaging of psychedelic action.

International review of neurobiology 2025 Paul Cumming, Klemens Egger, Gitte M. Knudsen 2 citations

Molecular brain imaging by positron emission tomography (PET) and single photon emission computer-tomography (SPECT) entails the mapping of the cerebral distribution of radiopharmaceuticals that track physiological processes such as blood perfusion and glucose metabolism, or the abundance in brain of specific molecular targets such as neuroreceptors. PET and SPECT emerged as useful in vivo...

DOI: 10.1016/bs.irn.2025.02.005 Full text LSD Cerebral blood flow Metabolism Psychedelics: psilocybin +4

Meditating on psychedelics. A randomized placebo-controlled study of DMT and harmine in a mindfulness retreat

Journal of Psychopharmacology September 27, 2024 Daniel Meling, Klemens Egger, Jovin Mueller et al. 15 citations

Background: In recent years, both meditation and psychedelics have attracted rapidly increasing scientific interest. While the current state of evidence suggests the promising potential of psychedelics, such as psilocybin, to enhance meditative training, it remains equivocal whether these effects are specifically bound to psilocybin or if other classical psychedelics might show synergistic...

DOI: 10.1177/02698811241282637 Ayahuasca Meditation Mindfulness Psilocybin +4

Neurobiological research on N,N-dimethyltryptamine (DMT) and its potentiation by monoamine oxidase (MAO) inhibition: from ayahuasca to synthetic combinations of DMT and MAO inhibitors.

Cellular and molecular life sciences : CMLS September 10, 2024 Klemens Egger, Helena Aicher, Paul Cumming et al. 30 citations

The potent hallucinogen N,N-dimethyltryptamine (DMT) has garnered significant interest in recent years due to its profound effects on consciousness and its therapeutic psychopotential. DMT is an integral (but not exclusive) psychoactive alkaloid in the Amazonian plant-based brew ayahuasca, in which admixture of several β-carboline monoamine oxidase A (MAO-A) inhibitors potentiate the activity...

DOI: 10.1007/s00018-024-05353-6 Full text Ayahuasca DMT Neural plasticity Psychedelics entheogens +10

Pharmacokinetic and Pharmacodynamic Interaction of the Ayahuasca Constituents Harmine and Dimethyltryptamine (DMT) in the Rat Brain

January 4, 2023 Klemens Egger, Frederik Gudmundsen, Naja Støckel Jessen et al. preprint

RationaleThe psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are attributed to the effects of N,N-dimethyltryptamine (DMT) at brain serotonin 5-HT2A receptors. To make oral DMT bioavailable, ayahuasca additionally contains reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine. However, there is lacking biochemical...

DOI: 10.31219/osf.io/cv6ey Ayahuasca Harmine Pharmacology Harmaline +5

A pilot study of cerebral metabolism and serotonin 5-HT2A receptor occupancy in rats treated with the psychedelic tryptamine DMT in conjunction with the MAO inhibitor harmine.

Frontiers in Pharmacology 2023 Klemens Egger, Frederik Gudmundsen, Naja Støckel Jessen et al. 17 citations

Rationale: The psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are often attributed to agonism at brain serotonin 5-HT2A receptors by N,N-dimethyltryptamine (DMT). To reduce first pass metabolism of oral DMT, ayahuasca preparations additionally contain reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine....

DOI: 10.3389/fphar.2023.1140656 Full text DMT Ayahuasca Pkpd 18 Ffdg-PET +7

Monoamine Oxidase Inhibition by Plant-Derived β-Carbolines; Implications for the Psychopharmacology of Tobacco and Ayahuasca

Frontiers in Pharmacology May 2, 2022 Ilana Berlowitz, Klemens Egger, Paul Cumming 32 citations

The monoamine oxidases (MAOs) are flavin-containing amine oxidoreductases responsible for metabolism of many biogenic amine molecules in the brain and peripheral tissues. Whereas serotonin is the preferred substrate of MAO-A, phenylethylamine is metabolized by MAO-B, and dopamine and tyramine are nearly ambivalent with respect to the two isozymes. β-Carboline alkaloids such as harmine,...

DOI: 10.3389/fphar.2022.886408 Ayahuasca Serotonin Pharmacology Monoamine neurotransmitter +10

Meditation, Psychedelics, and Brain Connectivity: A Randomised Controlled Resting-State fMRI Study of N,N -Dimethyltryptamine and Harmine in a Meditation Retreat

medRxiv Klemens Egger, Daniel Meling, Firuze Polat et al. preprint

Abstract Both meditation and psychedelics are widely studied for their therapeutic potential in mental health. Recent research suggests potential synergies between mindfulness practice and psychedelics, though empirical studies have primarily focused on psilocybin. This study investigates the distinct and combined effects of mindfulness practice and an ayahuasca-inspired formulation containing...

DOI: 10.1101/2025.07.30.25332422

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