Receptor activity
5-MeO-DMT is an agonist at serotonin receptors, with notably high affinity at 5-HT1A alongside its activity at 5-HT2A. Most classic psychedelics are discussed almost entirely in terms of 5-HT2A, and the subjective effects of psilocybin and LSD track 5-HT2A occupancy closely. The relatively greater 5-HT1A contribution here is the leading explanation for why the experience is so different: less visual construction, more dissolution of the self-model.
That explanation is plausible and incomplete. Receptor binding profiles are measured in tissue and in cell lines. Translating them into an account of what a person experiences involves several inferential steps, and anyone presenting the 5-HT1A story as settled fact is overstating it.
Metabolism
Two routes dominate. Monoamine oxidase A deaminates 5-MeO-DMT, which is the main clearance pathway and the reason MAO inhibition is so consequential. Cytochrome P450 2D6 O-demethylates it to bufotenine, a compound with its own pharmacology.
CYP2D6 activity varies enormously between people on genetic grounds. Poor metabolisers, extensive metabolisers, and ultra-rapid metabolisers exist in every population at different frequencies. Two people given identical amounts can have meaningfully different exposure. This is one of the reasons that experience with one person tells you less than you would like about the next.
Onset and duration
Route changes the shape of the curve dramatically. Vaporised, onset is within seconds, the peak arrives within the first few minutes, and the acute effects generally resolve inside twenty to thirty minutes. Intranasal and intramuscular routes are slower to arrive and longer to resolve. Orally it is largely inactive on its own, because MAO-A clears it before it reaches the brain, which is exactly why the traditional South American preparations are snuffs rather than drinks.
Short duration is often described as a safety feature. It is better understood as a compression of risk into a very small window. Whatever is going to happen, happens fast, and there is little time to respond to it.
What the body does
Commonly reported acute physiological effects include a rise in blood pressure and heart rate, flushing, muscular rigidity or tremor, nausea and vomiting, and irregular or briefly suspended breathing. Loss of postural control is usual rather than exceptional. Incontinence occurs. Vomiting while unable to protect one's own airway is a recognised aspiration hazard.
None of this is rare or unexpected. It is the ordinary presentation, and it is the reason that physical setting and medical screening are not decorative concerns.
Interactions that matter
- MAO inhibitors. Irreversible MAOIs remove the primary clearance pathway. The combination has been implicated in fatalities, including a documented death involving 5-MeO-DMT together with harmaline. This is the single most serious interaction in the literature.
- SSRIs, SNRIs, and other serotonergic drugs. Raise the theoretical risk of serotonin toxicity. Long half-life agents such as fluoxetine complicate any washout calculation, and stopping an antidepressant carries its own real risks.
- CYP2D6 inhibitors. Including some antidepressants and some common over-the-counter medicines. They shift the metabolic balance in ways that are not predictable per person.
- Stimulants and cardiovascular medications. Compound the haemodynamic load in the acute window.
What is still unsettled
Human pharmacokinetic data remains limited. The contribution of bufotenine as an active metabolite is not well characterised. There is no established therapeutic window described in peer-reviewed human work in the way there is for psilocybin. Long-term outcome data beyond a few months is scarce.
We say this plainly in class because the confident-sounding version circulates widely and it is not supported.