Rat Study Challenges Brain DMT Theory: No Detectable DMT Found in Serotonin Neurons
For decades, the hypothesis that the human brain naturally produces dimethyltryptamine (DMT), a potent psychedelic compound, has captivated researchers and the public alike. Speculation has centered on DMT potentially functioning as a natural signaling molecule within the brain, possibly acting alongside serotonin. However, a new study conducted by researchers at the University of Southern Denmark and Bern University Hospital casts doubt on this theory, finding no evidence of naturally occurring DMT in the rat brain.
The Search for Endogenous DMT
Previous research demonstrated that mammals, including rats, possess the enzyme indolethylamine N-methyltransferase (INMT), which is capable of synthesizing DMT.1 Despite this, whether DMT actually occurs in the brain in measurable amounts remained unclear. The recent study aimed to determine if DMT is naturally present in the rat brain and whether it is stored in the nerve cells that release serotonin.
Key Findings of the Study
The researchers found no evidence of naturally occurring DMT in the adult rat brain, even when they attempted to prevent its breakdown. They observed no accumulation of administered DMT within serotonin neurons. “We found no evidence of naturally occurring DMT in the adult rat brain—even when we inhibited its breakdown—nor did we observe that administered DMT was stored in serotonin neurons,” explains Mikael Palner, Associate Professor at the Department of Clinical Research and first author of the study.
The study involved measuring DMT levels in specific brain regions of adult rats. Researchers also investigated whether administered DMT could be absorbed and stored in serotonergic neurons using the serotonin transporter (SERT) and vesicular monoamine transporter 2 (VMAT2).
What Do These Results Mean?
According to Palner, the findings strongly suggest that DMT is neither formed nor stored in serotonin terminals within the rat brain. Any naturally occurring DMT levels, if present, must be extremely low or regulated by mechanisms outside of the brain’s serotonin system. “Our findings strongly indicate that DMT is neither formed nor stored in serotonin terminals in the rat brain, and that any natural levels must be extremely low or regulated by mechanisms outside the brain’s serotonin system,” Palner stated.
These results build it less likely that DMT functions as a classical signaling substance within the serotonin system of adult rats. If DMT does have a biological role, it may be linked to other cell types, tissues, or physiological states not examined in this study.
Understanding DMT
N,N-dimethyltryptamine (DMT) is a psychedelic compound found in certain plants, notably as the active component of Ayahuasca.1 Chemically, it is closely related to serotonin, a crucial neurotransmitter. In popular culture, DMT has been associated with dreams and near-death experiences.1
Key Questions with Mikael Palner
What did you investigate in the study?
“There is a long-standing debate whether the psychedelic compound DMT (N,N-dimethyltryptamine), also the active compound of the Ayahuasca, is a native compound in the mammalian brain, and possibly stored in serotonin neurons. Here we used highly sensitive and quantitative methods to examine whether DMT is naturally available and additionally if DMT can be stored in serotonin‑releasing nerve terminals in the rat brain.”
What is the key finding?
“We found no detectable evidence that endogenous DMT exists in the adult rat brain, even after blocking its normal metabolic breakdown, a process that increases and prolong the availability of administrated DMT. We also saw no meaningful retention of administered DMT inside serotonin terminals.”
How can the findings be used?
“The findings clarify an ongoing scientific debate by showing that serotonin neurons are unlikely to store or accumulate DMT, and that the examined brain regions do not contain native DMT. This helps narrow the search for where DMT may originate or act in the brain, if it is at all present.”
Study Details
The researchers analyzed several brain regions in adult rats using quantitative methods capable of detecting trace substances. Their findings were published in Neuropharmacology in February 2026.2
Citation: Palner, M., et al. (2026). N,N-dimethyltryptamine (DMT) is neither formed nor retained in serotonin terminals in the rat brain. Neuropharmacology. https://doi.org/10.1016/j.neuropharm.2026.110874
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