DMT: The Neuroscience

In 1956, a Hungarian psychiatrist named Stephen Szára — refused a supply of LSD by Sandoz because he worked behind the Iron Curtain — synthesised a different molecule and injected it into his own arm. Within minutes the room dissolved into “brilliantly coloured oriental motifs” and then into rushing visions; half an hour later it was over. The compound was N,N-dimethyltryptamine, DMT, and Szára had just discovered the strangest entry in the psychedelic catalogue: a substance that is shatteringly powerful yet gone in the time it takes to drink a coffee, that the human body destroys almost as fast as it can act, and that — most provocatively — the brain itself may quietly manufacture. This is the neuroscience of DMT: how the shortest trip became the most extreme, what it does to the order of the cortex, why its users keep meeting “someone” in the dark, the contested claim that it is made inside us, and the early attempts to turn it into medicine.

The Molecule: A Trip Measured in Minutes

DMT is the most chemically minimal of the classic psychedelics — a tryptamine so close to serotonin that the brain treats it as a near-twin. That simplicity comes with a catch: the same enzyme that recycles serotonin, monoamine oxidase (MAO), tears DMT apart within minutes. Swallowed on its own, DMT does nothing at all, destroyed by MAO in the gut and liver before it can reach the brain. Smoked or injected, it bypasses that gauntlet and floods the brain in seconds — effects peak in about a minute and are largely gone within ten to twenty. There is no plateau, no long arc; it is closer to a detonation than a journey. This is also the secret of ayahuasca: Amazonian brewers combine a DMT-containing plant with a vine rich in MAO-inhibiting β-carbolines, shutting down the enzyme so the same molecule becomes orally active and lasts for hours. The pharmacology that makes pure DMT a five-minute storm makes brewed DMT an all-night ceremony.

The Receptor: Serotonin’s Wild Cousin

Like LSD, psilocybin, and mescaline, DMT does its primary work as an agonist at the serotonin 2A (5-HT2A) receptor on cortical neurons — the shared switch of the classic psychedelic state. But DMT is promiscuous. It also activates 5-HT1A receptors and, in a celebrated 2009 Science paper from Arnold Ruoho’s lab, was identified as an endogenous ligand of the sigma-1 receptor, a chaperone protein implicated in cellular stress and neuroprotection. That sigma-1 finding is real but should be read carefully: DMT’s grip on sigma-1 is far weaker than its grip on serotonin receptors, so its role in the acute psychedelic effect is debated, and it is more often invoked for DMT’s possible protective and immune-modulating actions. It is worth distinguishing DMT from its close relative 5-MeO-DMT, the toad molecule: where N,N-DMT is rich in form and visionary content, 5-MeO is biased toward the 5-HT1A receptor and produces a far more formless, all-consuming dissolution. Same family, opposite emphasis.

The Brain on DMT: The Hierarchy Collapses

What happens in a brain undergoing this five-minute storm? The clearest picture comes from Chris Timmermann, Robin Carhart-Harris and colleagues at Imperial College London. Their 2019 EEG study found that DMT suppressed alpha rhythms — the brain’s default “resting” oscillation — while sharply increasing signal diversity, a measure of the richness and unpredictability of brain activity that rose in lockstep with the intensity of the experience. Then, in a landmark 2023 paper in PNAS, the group recorded DMT with simultaneous EEG and fMRI. They found that DMT dramatically increased global functional connectivity — regions that normally keep to themselves began talking across the whole cortex — and, most strikingly, collapsed the brain’s hierarchical organisation. The normal gradient that runs from basic sensory areas up to abstract association cortex compressed and flattened; the brain’s ordered chain of command dissolved into something more uniform and interconnected. The effects were largest in the evolutionarily newest, most richly connected association cortex, and the rise in signal diversity again tracked how vivid and immersive the experience felt. It is the “entropic brain” hypothesis made visible: order giving way to a higher-entropy, hyper-connected state.

The Entities and the Near-Death Brain

No account of DMT is honest without its most disconcerting feature: people keep meeting beings. In a 2020 survey of 2,561 DMT users led by Alan Davis and Roland Griffiths, around three-quarters reported encountering an autonomous “entity” — and the encounters were not dismissed as hallucination. Most participants placed the entity in a reality that felt “real but different,” the majority believed it continued to exist after the experience ended, and roughly 80% said it had altered their fundamental conception of reality; many ranked it among the most meaningful experiences of their lives. Running alongside the entity phenomenon is an equally provocative overlap: in a 2018 study, Timmermann and colleagues found that DMT reproduces the core features of the near-death experience. Every volunteer crossed the standard clinical threshold for an NDE, and their scores were statistically comparable to those of people who had survived genuine brushes with death. Neuroscience can map the brain state that hosts these experiences; what it cannot yet explain is why their content — the beings, the sense of another world, the encounter with death — is so consistent from one stranger to the next.

The Spirit Molecule Question: Does the Brain Make DMT?

DMT’s enduring mystique rests on a single, contested claim: that it is produced inside the mammalian brain. The case has grown more serious than folklore. The enzyme thought to build DMT, INMT, is present in neural tissue; in 2013 Steven Barker and Jimo Borjigin detected DMT in the pineal gland of living rats by microdialysis; and in a 2019 Scientific Reports study, the Borjigin lab found DMT in the rat cortex at concentrations broadly comparable to serotonin and dopamine, with levels that rose around cardiac arrest and persisted even after the pineal was removed — suggesting the brain at large, not just the “third eye,” can make it. But the rebuttal is forceful and deserves equal weight. David and Charles Nichols argued in 2020 that the measured amounts are orders of magnitude too low to meaningfully activate receptors that serotonin already occupies far more tightly — at the moment of death, serotonin surges twenty-fold while DMT rises only modestly, so any DMT signal would be drowned out. And a 2023 study found that rats lacking the INMT gene still methylated tryptamines, casting doubt on the assumed biosynthetic pathway altogether. The honest verdict: DMT and its machinery are detectably present in the brain, but whether they are produced in functionally relevant amounts, by which enzyme, and to any behavioural end, remains genuinely unresolved. The “spirit molecule” is a live scientific question — not yet an answer.

Neuroplasticity: The Psychoplastogen

Beyond the acute experience, DMT belongs to a class of compounds that may physically remodel the brain. In an influential 2018 Cell Reports study, David Olson’s lab showed that DMT promotes structural neural plasticity — growing new dendritic spines and strengthening synapses in cortical neurons, an effect comparable in magnitude to ketamine and dependent on the 5-HT2A–TrkB–mTOR signalling pathway. Olson coined the term “psychoplastogen” for molecules like this, and the finding underwrites much of the therapeutic excitement: a five-minute drug that triggers days of structural rewiring is an attractive antidepressant candidate. Two cautions keep the science honest. First, the plasticity story is largely preclinical — cells and rodents, not yet human brains. Second, dose matters enormously: a 2019 study found that chronic low (microdose-range) DMT in rats did not reproduce the spine growth and in some cases reduced it, a sex-specific effect — so the high-dose and microdose stories must not be conflated. DMT may also encourage the birth of new neurons in the hippocampus through its sigma-1 activity, a separate and still-emerging thread.

The Clinic and the Extended State

The therapeutic frontier is moving, if cautiously. Small Pharma ran the first modern trial of injectable DMT-assisted therapy for major depression and reported positive Phase 2a topline results in 2023 — a single dose producing a meaningful drop in depression scores against placebo — though these remain company-reported figures awaiting full peer-reviewed publication. After Cybin acquired Small Pharma later that year, the lead programme became CYB004, a chemically “deuterated” DMT engineered to last longer in the body, now in Phase 2 trials for generalized anxiety disorder. Parallel to the clinic, researchers have begun to bend DMT’s defining limitation — its brevity. Using a bolus followed by a continuous infusion, teams in London (2024) and Basel (2025) have held volunteers in a stable, extended DMT state for roughly half an hour to two hours, long enough to study a sustained psychedelic plateau and, in the Basel work, to let participants titrate the depth themselves. (Multi-hour “DMTx” experiences promoted outside academia remain unverified by published trials.) The London group also observed an unexpected acute tolerance: as the infusion continued, blood levels kept climbing while the subjective intensity plateaued — the brain, it seems, adapts even within a single session.

The Synthesis

DMT is a study in paradox. It is the briefest of the great psychedelics and the most extreme; the simplest in structure and the strangest in effect; possibly endogenous and yet, by the best critiques, probably inert at the levels we make. In minutes it does what its slower cousins take hours to achieve — raising the brain’s connectivity, flattening its hierarchy of command, and ushering in a world so vivid and peopled that most who visit return convinced it was, in some sense, real. The risks are real too: the experience is overwhelming and uncontrollable once begun, it raises heart rate and blood pressure, and it is unsafe for those with a personal or family history of psychosis or bipolar disorder — and combining it with an MAO inhibitor, as ayahuasca does, adds serious medical interactions. This article is education, not medical advice. What makes DMT matter to neuroscience is not the mysticism but the leverage: a molecule that can switch a human brain into its most entropic state and back again in the span of a single song is one of the most precise tools we have for asking what consciousness is made of — and whether the boundary between the world out there and the world within is as solid as it feels.