A Critical Evaluation of the Hypothesis that N,N-Dimethyltryptamine has Endogenous Functions
Zenodo (CERN European Organization for Nuclear Research) June 22, 2026 Peer reviewed DOI: 10.5281/zenodo.20823985 via OpenAlex
Summary
DMT may have an endogenous function in the human body, but evidence is mixed and contested. While DMT concentrations are reported in the nM range similar to serotonin and dopamine, other studies show it is below detection in rat brains. Clinical trials indicate high-dose DMT can produce antidepressant effects, yet this does not confirm any physiological role. A proposed hypothesis suggests DMT might support neuroplasticity, with its decline possibly linked to cognitive decline with age.
Study at a glance
| Design | critical evaluation |
|---|---|
| Key finding | The evidence regarding DMT's endogenous function is mixed and contested, with some studies showing low concentrations while others report antidepressant effects. |
Abstract
The human body possesses enzymatic machinery to both synthesize and rapidly degrade N,N-dimethyltryptamine (DMT). This coexistence raises a question: does DMT serve an endogenous function, or is it a metabolic byproduct with no physiological role? DMT is structurally almost identical to serotonin and binds to the same serotonin receptors. Serotonin is universally accepted as a neurotransmitter with essential functions. If DMT were merely a metabolic byproduct, why would the body produce a molecule shaped like serotonin and binding to serotonin receptors through regulated enzymatic steps? This paper critically evaluates the hypothesis that DMT is an endogenous molecule with physiological functions. The evidence is mixed and contested. Barker (2025) reports DMT concentrations in the nM range, comparable to serotonin and dopamine. Palner et al. (2026) report that DMT is below the detection limit in rat brain. The sigma-1 receptor affinity (Ki ~14 μM) is three orders of magnitude higher than reported physiological concentrations. The intracellular 5-HT2A receptor finding (Barker 2025) has not been independently replicated. The dietary DMT gap has not been directly measured. Clinical trials demonstrate that high-dose DMT produces antidepressant effects (Erritzoe et al. 2026; Falchi-Carvalho et al. 2025), but clinical efficacy does not establish endogenous function. Based on this critical evaluation, a companion paper (Solis, 2026b) proposes and evaluates a focused hypothesis: that DMT maintains neuroplasticity, and that its decline may contribute to age-related cognitive decline. The present paper outlines a research program to test whether DMT has physiological functions, while acknowledging that the prior probability of endogenous function may be low given the current state of the evidence.