DMT: general

DMT (N,N-dimethyltryptamine) is a naturally occurring hallucinogenic compound found in plant and animal tissue, including mammalian brain, blood, and urine [1][2]. It's also made synthetically [3]. It's structurally related to LSD [4] and acts on the serotonin system, working as an agonist at some serotonin receptor types and an antagonist at others [2]. In large enough doses it produces a "high" and distorts perception, so users see or feel things that aren't there [5].

Taken by mouth alone, DMT doesn't produce effects — it has to be injected, sniffed, smoked, or taken with something that stops it being broken down in the gut, as in ayahuasca [4][1]. That last combination matters: ayahuasca pairs DMT with an MAOI, and MAOIs mixed with SSRIs or other serotonergic drugs can cause serotonin syndrome [6]. As with serotonergic psychedelics generally, serotonin toxicity is a combination risk: it typically arises when a serotonin-raising drug is combined with an MAOI — the pairing ayahuasca is built on — while serotonergic antidepressants that don't contain MAOIs are low-risk alongside MAOI-free psychedelics [7]. Some combinations present a significant risk of serotonin toxicity while others are likely benign [7].

The two things worth knowing before anything else: the experience is short but intense, so preparation matters more than with slower-acting psychedelics [8], and getting the form, method, and dose right for what you're actually taking matters — smoked or vaporized DMT, injected DMT, and ayahuasca are different enough in onset and intensity that mixing up methods is a real risk [8]. Know what you're taking and how you're taking it before you take it, and know what else is in your system — prescription antidepressants included [8].

References

1. DMT Therapy Information — UC Berkeley Center for the Science of Psychedelics
2. Dimethyltryptamine — DrugBank
3. N,N-Dimethyltryptamine (DMT) — U.S. Drug Enforcement Administration
4. DMT — Encyclopaedia Britannica
5. DMT: Uses, Health Effects, Safety, Risks, and Legal Status — WebMD
6. Drug–drug interactions involving classic psychedelics: A systematic review — Journal of Psychopharmacology
7. Serotonin toxicity of serotonergic psychedelics — PubMed
8. DMT — Drug Science