Ask a room full of people whether cannabis is a psychedelic and you will get an argument. Ask a pharmacologist and you will get a firm no: THC and psilocybin work through different receptors, belong to different drug families and, in almost every textbook, sit in different chapters. But the textbooks describe how a drug works in the brain. They do not describe how it feels. And a small group of researchers at Johns Hopkins has now put that second question to the test directly, by giving the same four people 25 mg of psilocybin and 25 mg of oral THC on separate days and asking them, in effect, to tell the two apart.
The results were published on 27 August 2026 in the journal Psychopharmacology and are available in full here. The finding that travelled fastest, first reported by Marijuana Moment, is that on the standard questionnaires used to measure altered states of consciousness, 25 mg of oral THC produced a profile that looked qualitatively similar to 25 mg of psilocybin. The finding that matters just as much is the sample size: four. Not four hundred. Four.
Key Takeaways
Four healthy adults, aged 31 to 47, each took placebo, 25 mg of psilocybin and 25 mg of THC in separate double-blind sessions modelled on psychedelic clinical research — couch, eye shades, curated music, two trained facilitators. On altered-state and mystical-experience scales, the THC sessions looked qualitatively similar to the psilocybin sessions. Two participants who received synthetic THC rated their experience as more like a classic psychedelic than like a cannabinoid; the two who received a botanical cannabis distillate correctly identified it as cannabis. Doubling the dose to 50 mg did not make things more psychedelic — it made them more sedative and dissociative. The authors call this a pilot study and note that the sample was too small to run inferential statistics at all, which means the honest summary is that this is a signal worth chasing, not a conclusion. It also does not show that THC and psilocybin work the same way in the brain. They do not. What it suggests is that the subjective experience produced by THC may be far more sensitive to dose and context than most people assume.
What the researchers actually did
The design was small but deliberate. Four healthy adults between 31 and 47 each attended separate double-blind sessions in which they received a placebo, 25 mg of psilocybin, and 25 mg of THC. Two of the four also received a 50 mg dose of THC.
The THC came in two different forms, which turns out to matter. Two participants were given dronabinol, a pharmaceutical-grade synthetic THC that is more than 99% pure. The other two received a botanical cannabis distillate containing 89.9% THC, with trace amounts of other cannabinoids alongside it. Dronabinol is not an exotic research chemical — it is a licensed medicine, and it has appeared in other recent trials, including a study on THC and PTSD nightmares that used it in a very different clinical context.
The setting was borrowed wholesale from psychedelic research. Participants lay on a couch, wore eye shades, listened to a music playlist and were accompanied throughout by two trained facilitators. They were encouraged to direct their attention inward and stay with whatever came up. Anyone who has read a description of a psilocybin trial will recognise the setup immediately. Anyone who has spent time in cannabis culture will also recognise it as roughly what a certain kind of consumer sets up on purpose.
What the four people reported
Here is where the study gets genuinely interesting, and also where it gets messy.
The two participants who took 25 mg of dronabinol rated the experience as more similar to a classic psychedelic than to a cannabinoid. One of them also rated it as resembling a dissociative. The two who took the botanical distillate did the opposite: they correctly picked cannabis as the closest match.
So the blind test split down the middle, and it split along the line of the product, not the dose. Same amount of THC, different formulation, different verdict.
But when the researchers stopped asking “what do you think you took” and instead used the validated scales built to measure altered states of consciousness and mystical-type experiences, the picture converged. On those instruments, both forms of THC at 25 mg produced profiles that were qualitatively similar to what 25 mg of psilocybin produced. The distillate was also rated as producing a stronger overall subjective effect than the equivalent dose of dronabinol — which is a small but pointed reminder that whole-plant extracts and isolated molecules are not interchangeable, a theme that keeps recurring across cannabis science.
The 50 mg dose is the detail most likely to get lost in the retelling. More THC did not mean more psychedelic. The higher dose produced a different profile altogether, tilting sedative and dissociative in some cases. That is not what you would expect if THC were simply a weak psychedelic that needed a bigger push.
Why this is not a claim about brain chemistry
It is worth being blunt about what the study does not show. It does not show that THC acts on the brain the way psilocybin does.
Psilocybin is a classic psychedelic, and its effects run largely through serotonin signalling, particularly at the 5-HT2A receptor. THC works through the endocannabinoid system, mainly at CB1 receptors. Two entirely different doors into the same building.
What the researchers compared is the phenomenology — the felt texture of the experience, as reported by the person having it. The useful analogy is a journey rather than a mechanism: two travellers can take completely different roads and still describe stretches of scenery that sound remarkably alike. That resemblance is real, and it is measurable with the questionnaires the field already uses. It is not evidence that the roads are the same road.
The other thing worth flagging is who these four people were. All four were white and non-Hispanic. Three had postgraduate education. None was selected to represent a typical cannabis consumer. The researchers say this themselves. With four participants, one unusual responder is 25% of your dataset.
This has been circling for years
The reason a four-person pilot got attention at all is that it lands on top of a small pile of earlier findings pointing the same direction.
In 2018, also at Johns Hopkins, researchers published a case report describing a 30-year-old man who experienced visual and auditory hallucinations after inhaling vaporised cannabis containing 25 mg of THC in a controlled experiment. It was unusual enough to be worth writing up on its own, and it let the team compare his subjective ratings against those seen with hallucinogens. Parts of the profile matched. The whole picture did not.
In 2021, researchers at the University at Albany asked whether intense cannabis experiences could produce what psychedelic researchers call oceanic boundlessness — a cluster of feelings involving unity, transcendence and the dissolving of the boundary between self and everything else. Participants described their most intense THC experience retrospectively, and between 17% and 19% reached levels the authors classed as “breakthrough” experiences. That is well short of the 59% reported in some psilocybin trials, but it is not zero.
In 2022, a University of Chicago team ran something more controlled: 25 healthy, infrequent cannabis users received placebo, 7.5 mg or 15 mg of oral THC. The study found dose-dependent increases across several dimensions of altered consciousness, including a measure called insightfulness — the sense of arriving at new understanding — and an increase in language entropy, a linguistic pattern previously documented with LSD.
Then in 2023, Johns Hopkins researchers assembled the pieces into a literature review published online that year and carried in the January 2024 issue of the Journal of Psychopharmacology. Their argument was specific: high-THC cannabis may well be capable of producing psychedelic-type effects, and the reason modern experiments rarely catch them is that the doses tend to be modest and the setting tends to be a clinical room with a computer in it. Change the dose, change the set and setting, and you might see something the field has been missing.
The 2026 pilot is, more or less, that proposal carried out.
The reason researchers care: an unblinding problem
There is a practical motive behind all of this, and it has nothing to do with settling arguments about whether weed is a psychedelic.
Psychedelic trials have a chronic methodological weakness known as functional unblinding. In theory, nobody knows who got the drug and who got the placebo. In practice, a person in the middle of a full psilocybin experience can work it out, and so can the researcher sitting across from them. That contaminates the blind, and it inflates expectancy effects in ways that are very hard to correct for afterwards. The comparators tried so far — inactive placebos, niacin, low-dose versions of the drug itself — have mostly failed for the same reason.
This is where THC becomes interesting to a trial designer. A dose of THC capable of producing an intense altered state through a completely different pharmacological mechanism would be much harder for a participant to distinguish from the real thing. It would be an active comparator that actually does something.
For now, that is a hypothesis and nothing more. The authors are explicit that four cases come nowhere near establishing THC as a viable active comparator, and they are calling for systematic studies with more participants and a wider range of doses. It is also worth noting that this kind of research runs into structural obstacles in the United States that have little to do with science — a problem that persists even as rescheduling debates promise to unlock cannabis research.
What a reader should take from this
If you came here asking whether THC feels like psilocybin, the honest answer is: sometimes, for some people, at high doses, in a setting engineered to encourage it — and four people is not enough to tell you how often.
What the study genuinely adds is a sharper sense of how unstable the THC experience is. Two people took an identical dose in an identical room and came out of it classifying the drug differently. Doubling the dose changed the character of the experience rather than intensifying it. The form of the product — synthetic isolate versus botanical distillate — shifted both the intensity and the way people categorised what had happened to them. That last point connects to a broader problem in cannabis research and retail alike: the number on the label is not a reliable description of the experience, and dose accuracy itself is far shakier than most consumers assume, as state-level potency audits keep demonstrating. The same goes for the assumption that other cannabinoids in a product will soften the effect — the first meta-analysis on CBD and THC interaction found the opposite of what the folk wisdom predicts.
None of that makes cannabis a psychedelic. It makes the cannabis experience a much more variable thing than the word “high” suggests.
FAQ
Not identically. In this pilot, the two participants who took a botanical cannabis distillate correctly identified it as cannabis. The two who took synthetic dronabinol rated it as closer to a classic psychedelic. On standardised altered-state questionnaires, however, the THC and psilocybin profiles looked qualitatively similar. With four people, that is a signal, not a general rule.
It is high for an oral dose, particularly for someone who uses cannabis rarely. Edible THC is absorbed slowly and converted in the liver into a metabolite that is more potent than inhaled THC, which is why oral doses that sound modest on paper can produce very strong effects. This article is not dosing guidance, and the participants here were dosed under medical supervision with facilitators present throughout.
Because the relationship between dose and subjective effect is not a straight line. At 50 mg, the profile shifted toward sedation and dissociation rather than intensifying the psychedelic-like features seen at 25 mg. Only two participants received that dose, so this observation carries even less statistical weight than the rest of the study.
Under federal law, psilocybin remains a Schedule I substance and can only be administered under a DEA registration and, where applicable, an FDA Investigational New Drug authorisation. Cannabis itself remains federally controlled, while dronabinol in approved formulations sits in a lower schedule as a prescription medicine. Studies like this one operate under specific federal licences and institutional review board approval. State laws differ, and neither the federal research framework nor any state programme makes personal use of psilocybin lawful.
Disclaimer
This article is journalism about published scientific research and is provided for informational purposes only. It is not medical advice, and nothing in it should be read as a recommendation to use, obtain or dose any substance, whether cannabis, THC, dronabinol or psilocybin. THC and psilocybin are controlled substances in most jurisdictions, and the legal status of each varies by country and, in the United States, by state. The study described here involved four participants under medical supervision and cannot support conclusions about how any individual will respond. If you are considering cannabis or any cannabinoid product in a medical context, consult a qualified healthcare professional familiar with your history and with the law where you live.
