For decades, the idea that the human brain might naturally produce the psychedelic compound DMT has attracted considerable attention. It has been speculated that DMT could function as a natural signalling substance in the brain – possibly as a co-transmitter alongside serotonin.
Previous research has shown that mammals, including rats, possess the enzyme indolethylamine N-methyltransferase (INMT), which can synthesise DMT. However, it has remained unclear whether DMT occurs in the brain in measurable amounts.
Researchers at the University of Southern Denmark (Mikael Palner) and Bern University Hospital (Paul Cumming) have now examined whether the rat brain naturally contains DMT and whether the substance can be stored in the nerve cells that release serotonin.
– 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, says Mikael Palner, Associate Professor at the Department of Clinical Research and first author of the study.
Mikael Palner and his research group measured DMT in selected brain regions in adult rats.
What do the results mean?
– 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, explains Mikael Palner.
The findings make it less likely that DMT plays a role as a classical signalling substance in the serotonin system in adult rats.
If DMT has a biological function, it may be linked to other cell types, other tissues or specific physiological states that were not included in this study.
What is DMT?
N,N-dimethyltryptamine (DMT)
• A psychedelic compound that is also found in certain plants, and the active component in Ayahuasca.
• Chemically related to the signalling substance serotonin
• In popular culture, it has been linked to dreams and near-death experiences
• Can be synthesised in mammalian tissue via the enzyme indolethylamine N-methyltransferase (INMT)
Three questions for Mikael Palner about the study
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.
About the study
Method: The researchers analysed several brain regions in adult rats using quantitative methods capable of detecting trace substances.
They also examined whether administered DMT could be taken up and stored in serotonergic neurons via the serotonin transporter (SERT) and vesicular monoamine transporter 2 (VMAT2).
Funding: The study was supported by a grant from the Swiss National Science Foundation (Grant Number 320030 204978).
Read more: The study N,N-dimethyltryptamine (DMT) is neither formed nor retained in serotonin terminals in the rat brain is published in the journal Neuropharmacology : https://doi.org/10.1016/j.neuropharm.2026.110874
Neuropharmacology
10.1016/j.neuropharm.2026.110874
Experimental study
Animals
N,N-dimethyltryptamine (DMT) is neither formed nor retained in serotonin terminals in the rat brain
16-Feb-2026