DMT vs ketamine: a classic psychedelic and a dissociative, side by side

THE SHORT VERSION · SWIPE

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People compare DMT and ketamine because both can produce sudden, overwhelming changes in perception, reports of leaving the body and, for some, experiences that resemble dying. Both are also studied for depression. Under the surface they work through different brain systems, carry different risks and sit in different places in Canadian law and medicine. For DMT on its own, start with what is DMT.

DMT vs ketamine: how do they compare at a glance?

The table sums up the main differences. Each row is explained, with sources, in the sections below. It compares what studies and official documents report, not which drug is “stronger” or “better” for anyone.

How do DMT and ketamine work in the brain?

DMT: a serotonin 5-HT2A agonist

DMT belongs to the classic psychedelics, the family that includes psilocybin and LSD. Researchers describe it as a serotonin 5-HT2A agonist, meaning it binds to and activates that receptor (Gouzoulis-Mayfrank et al., 2005), and as an endogenous one, meaning the body makes small amounts of it (Martial et al., 2019). Evidence: established. The receptor story is told in DMT and the 5-HT2A receptor.

Ketamine: an NMDA receptor blocker

Ketamine works on a different chemical messenger, glutamate. A 1994 Yale paper describes it as a derivative of phencyclidine, a “dissociative anesthetic” and a noncompetitive antagonist of the NMDA receptor, one of the main glutamate receptors (Krystal et al., 1994). An antagonist blocks a receptor rather than activating it. Esketamine is one of the two mirror-image forms that make up ordinary ketamine. Health Canada’s monograph calls it a non-competitive NMDA antagonist and says how it acts in depression is unknown (Spravato product monograph). Evidence: established.

“Dissociative” has a specific origin. The Canadian Ketalar monograph says the anesthetic state ketamine produces has been termed “dissociative anesthesia” because it appears to interrupt association pathways in the brain before it blocks body sensation (Ketalar product monograph). Evidence: established as the official description.

Is ketamine a psychedelic?

Not in the classic sense. Researchers group both drugs as hallucinogens, but they keep them in separate classes: “glutamate antagonists” such as PCP and ketamine on one side, and “serotonergic hallucinogens” such as LSD, psilocybin and DMT on the other (Gouzoulis-Mayfrank et al., 2005). In everyday writing ketamine is sometimes called a psychedelic because it alters perception, but its mechanism is not the 5-HT2A route that defines the classic group. Evidence: established for the mechanism; the label is a matter of usage.

So in the “ketamine vs psychedelics” debate, the main difference is the receptor, not how unusual the experience feels. Our three-way guide to psilocybin, LSD and DMT covers the classic group in more depth.

What happened when researchers gave both to the same people?

A German team ran the only direct comparison we found. In a double-blind crossover study (each volunteer received both drugs on different days, without knowing which), 15 healthy volunteers were enrolled and 9 completed both drugs at both doses. Overall intensity was similar. Effects resembling the “positive” symptoms of psychosis, especially disordered thinking and inappropriate emotion, were stronger after DMT. Effects resembling “negative” symptoms, attention problems, disturbed body perception and catatonia-like movement changes were stronger after S-ketamine (esketamine) (Gouzoulis-Mayfrank et al., 2005). Evidence: preliminary, from 9 people.

The same programme measured the brain and reflexes. S-ketamine increased prepulse inhibition, a measure of how the brain filters a startle sound, while DMT had no significant effect on it (Heekeren et al., 2007). In a brain-imaging study of 14 volunteers, DMT reduced activity in visual and hearing areas during an alertness task, while S-ketamine increased activity in other regions; the authors call their conclusions preliminary (Daumann et al., 2010). Evidence: preliminary.

These studies used both drugs as laboratory models of psychosis in screened, healthy volunteers. They describe how the states differ under controlled conditions. They do not describe what either drug does to anyone outside a study.

What do the DMT and ketamine experiences have in common?

What each looks like in lab reports

In early-1990s New Mexico studies, intravenous DMT brought a brief, overwhelming “rush” and a sense of loss of control, then a dissociated state in which euphoria alternated or coexisted with anxiety. Visual effects were a rapidly moving, brightly coloured display, and the effects “completely replaced” ongoing mental experience (Strassman et al., 1994). Evidence: established, from 12 experienced volunteers.

In a randomized, double-blind, placebo-controlled study of 19 healthy volunteers, ketamine produced changes in perception, symptoms similar to dissociative states, effects resembling both positive and negative symptoms of schizophrenia, and impaired memory for words recalled later (Krystal et al., 1994). Evidence: established. More on the DMT side is in what does DMT feel like.

The near-death experience comparison

Both drugs appear in research on near-death experiences (NDEs), the reports some people give after coming close to death. In a placebo-controlled lab study, 13 healthy volunteers rated their DMT experience on a standard NDE scale. All of them scored at or above the usual threshold for an NDE, though one also reached it after placebo, and NDE-like features rose significantly compared with placebo. Scores were linked to ego dissolution and mystical-type experience, and the profiles overlapped with those of people who had real NDEs (Timmermann et al., 2018). Evidence: preliminary, from 13 people.

A larger language study compared about 15,000 written drug reports covering 165 substances with 625 NDE narratives. Ketamine reports were consistently the most similar to NDEs, followed by salvia and then a series of serotonergic psychedelics including DMT (Martial et al., 2019). The authors suggested ketamine as a reversible experimental model of NDEs. Evidence: preliminary, because the reports were self-selected and unverified.

A 2025 case report described a 73-year-old woman who met NDE scale criteria after being anesthetized with ketamine for emergency intubation, with peacefulness, encounters with entities and a bright light (Fritz et al., 2025). She was also severely short of oxygen, so the case cannot separate the drug from the medical crisis. Evidence: preliminary, one case. The full picture is in DMT and near-death experiences and does the brain release DMT when you die.

Ego death on ketamine and DMT

“Ego death” is a popular phrase; researchers say ego dissolution, a compromised sense of self, which the developers of the main scale describe as a key feature of the psychedelic experience (Nour et al., 2016). In the DMT near-death study, NDE scores tracked ego dissolution (Timmermann et al., 2018). For ketamine, a 2026 study of 10 healthy volunteers found that changes in glutamate in a brain region called the nucleus accumbens were linked to “anxious ego dissolution” on a standard questionnaire (Gubser et al., 2026). Evidence: preliminary. See DMT ego death for what the term does and does not mean.

How long do DMT and ketamine last in studies?

Both act quickly, but the measured times come from specific study and clinical conditions and cannot be applied to anyone else. Our guide to how long DMT lasts covers the DMT timing studies in detail.

• DMT, intravenous in a lab: effects began almost at once, peaked at 90 to 120 seconds and were almost completely resolved by 30 minutes (Strassman et al., 1994). An inhaled-DMT trial describes a short duration of action, about 10 to 20 minutes (Falchi-Carvalho et al., 2025).
• Ketamine as an anesthetic: the Canadian monograph says an intravenous anesthetic dose usually works within 30 seconds and the anesthetic effect usually lasts five to ten minutes. Emergence reactions afterwards, such as vivid dreams, confusion or hallucinations, ordinarily last no more than a few hours (Ketalar product monograph).
• Esketamine nasal spray: blood pressure rises peak at about 40 minutes, dissociative effects generally start and resolve on the day of dosing, and patients must be monitored for at least 2 hours until clinically stable (Spravato product monograph).

Where do DMT and ketamine stand as medicines?

Ketamine: approved forms in Canada

Health Canada approved Spravato (esketamine nasal spray) on 20 May 2020, by prescription only (Health Canada, decision summary). The current monograph lists two uses in adults: with an SSRI or SNRI antidepressant, for major depression that has not responded to at least two antidepressants in the current episode, and short-term with an oral antidepressant when a depressive episode needs urgent psychiatric care (Spravato product monograph). Ordinary ketamine (Ketalar) is approved in Canada as an anesthetic only (Ketalar product monograph). Evidence: established.

Spravato is available only through a controlled distribution program, and patients use the spray under the direct supervision of a health care professional (Spravato product monograph). An early randomized ketamine depression trial, in 18 people with treatment-resistant depression, found improvement within 110 minutes of one infusion compared with placebo (Zarate et al., 2006). Evidence: established for the approval conditions; preliminary for that single small trial. Our guide to psilocybin vs ketamine therapy in Canada covers the trials and coverage in detail.

Blinding is a known problem, because the effects are obvious. In a 2023 trial of 40 surgical patients with depression, ketamine given while they were under general anesthesia, so no one could tell what they had received, was no better than placebo over the next three days (Lii et al., 2023). Evidence: preliminary, one small trial.

DMT: early trials, no approval

No DMT product appears in Health Canada’s Drug Product Database (Drug Product Database query). The most cited patient study is a Brazilian open-label trial, meaning there was no placebo group, in which 14 people with treatment-resistant depression inhaled DMT and showed lower depression scores a week later, with no serious adverse events (Falchi-Carvalho et al., 2025). Without a control group, that cannot show the drug caused the change. Evidence: preliminary. The wider trial picture is in DMT therapy research.

One study compared the two head to head for depression-like behaviour, but in mice: in a stress model, DMT and S-ketamine had similar effects, and some DMT effects lasted longer (de Sousa-Silva et al., 2026). Mouse results often do not carry over to people. Evidence: preliminary, in mice.

What are the known risks of DMT and ketamine?

Ketamine: dissociation, bladder damage and dependence

Spravato’s monograph carries a boxed warning: a high risk of dissociation and sedation after each dose, possible breathing problems, and blood pressure rises. It is not to be used where a rise in blood pressure or pressure inside the skull poses a serious risk. The monograph says esketamine can be abused, misused and cause physical dependence, and that people dependent on ketamine have reported withdrawal symptoms including cravings, anxiety, shaking, sweating and palpitations (Spravato product monograph). Evidence: established.

Bladder damage is the best-documented harm of heavy ketamine use. The Ketalar monograph reports severe urinary tract and bladder inflammation, including cystitis, in people with chronic ketamine use or misuse, and says dependence and tolerance may develop (Ketalar product monograph). A meta-analysis of 45 studies covering 4,921 patients with ketamine-associated bladder disease found frequent urination in 77.1%, urgency in 69.9% and pain above the pubic bone in 60.4%, and that stopping ketamine was necessary for improvement (Chan et al., 2022). Evidence: established.

A review for the UK Independent Scientific Committee on Drugs linked frequent, daily ketamine use with memory problems, and reported that many frequent users try but fail to stop (Morgan and Curran, 2012). Evidence: established for frequent use; most of this research is in people using ketamine outside medicine.

DMT: intense short-term effects, less long-term data

In controlled studies, DMT’s risks are mostly acute: a sense of loss of control, and anxiety alongside euphoria (Strassman et al., 1994). Those studies screened healthy, experienced volunteers and monitored them closely, so they say little about risks elsewhere. We found far less research on repeated DMT use than on ketamine. Evidence: established for the acute effects; long-term risks are unresolved. Our article on whether DMT is addictive covers dependence and dangerous drug interactions.

What about DMT and ketamine together?

Combining them is a risk. The same-person study above gave each drug on a separate day, never together, and we found no study of the combination. Its effects are unknown. If someone is in trouble after taking either drug, use the emergency numbers above.

Are DMT and ketamine legal in Canada?

Both are controlled under the Controlled Drugs and Substances Act. In the Justice Laws consolidation (current to 30 September 2026, last amended 18 July 2026), ketamine is listed in Schedule I under item 14, phencyclidine, its salts, derivatives and analogues. DMT is Schedule III, item 7. Section 4(1) bans possessing a Schedule I, II or III substance except as authorized under the regulations (CDSA). Evidence: established.

The practical difference is that ketamine and esketamine have approved medical uses with a prescription, while DMT has none (Spravato product monograph; Drug Product Database query). This is general information, not legal advice. For DMT in detail, see is DMT legal in Canada.

What is still unknown?

• Only one small within-person study, with 9 completers, has compared the DMT and ketamine states directly, so most comparisons are indirect (preliminary).
• Why ketamine reports read most like near-death narratives in text analysis, and whether that reflects the drug, the setting or who writes reports, is open (unresolved).
• Whether DMT has any effect in depression that a placebo-controlled trial can confirm is not yet known in the sources we read (unresolved).
• Long-term risks of repeated DMT use have far less data than ketamine’s documented bladder and dependence harms (unresolved).
• How two drugs with different receptor targets can both produce dissociation and entity reports is not explained (unresolved).

For another comparison of a non-serotonergic hallucinogen with DMT, see salvia vs DMT.

Shroomverse sells mushroom products. This article is general information about research, medicine and Canadian law on DMT and ketamine. It is not medical, legal or purchasing advice, and it does not recommend any product.