A four-person Johns Hopkins pilot study found that 25 mg of oral THC could produce altered-state profiles that qualitatively resembled those seen with 25 mg of psilocybin, particularly when consumed in a setting modeled on psychedelic research. The sample is far too small to establish cannabis as a psychedelic, but the findings add to earlier research suggesting that dose, context, and individual response can push THC experiences into unexpectedly psychedelic-like territory.
Cannabis and psychedelic mushrooms are not the same. They don’t work the same way in the brain, they don’t belong to the same pharmacological family and, generally speaking, they don’t feel the same either. But when the THC dose gets high enough, that line can start to feel a whole lot blurrier.
A new study from researchers at Johns Hopkins University found that 25 milligrams of oral THC can produce subjective experiences resembling those produced by 25 milligrams of psilocybin, the main psychoactive compound in psychedelic mushrooms, as reported by Marijuana Moment. In some cases, participants couldn’t even correctly identify which substance they had received.
Before we start declaring that weed has secretly been a psychedelic this whole time, though, there’s one very important piece of fine print: the study included just four people.
That’s it. Four.
The researchers themselves describe it as a pilot study and point out that the sample was so small that they couldn’t even run inferential statistical analyses. In other words, this is useful for spotting an interesting signal, not for making sweeping claims about how people in general respond to THC.
What makes that signal worth paying attention to is that it comes with a whole lot of scientific backstory.
Four People, THC, Psilocybin and a Room Built for Going Inward
The study, published August 27, 2026, in Psychopharmacology, included four healthy adults between the ages of 31 and 47. Across separate double-blind sessions, each received a placebo, 25 mg of psilocybin and 25 mg of THC. Two also received a 50 mg dose of THC.
The THC came in two formats. Two participants received dronabinol, a synthetic version containing more than 99% THC, while the other two received a botanical cannabis distillate containing 89.9% THC along with small amounts of other cannabinoids.
The study’s set and setting looked a lot like the kind of setup many users might deliberately seek out, though it’s also standard territory for psychedelic clinical research. Participants spent each session lying on a couch, wearing eye shades, listening to a music playlist and accompanied throughout by two trained facilitators. They were also encouraged to turn their attention inward and stay present with whatever arose in their consciousness.
And that’s where the line between a cannabis high and a mushroom trip started to become a little less obvious.
The two participants who received 25 mg of dronabinol rated the experience as more similar to that of a classic psychedelic—and, in one case, to a dissociative as well—than to a cannabinoid. By contrast, the two participants who received 25 mg of cannabis distillate correctly identified the experience as most similar to cannabis.
Still, when researchers used scales specifically designed to measure altered states of consciousness and mystical-type experiences, the profiles produced by 25 mg of THC, whether synthetic or in distillate form, were qualitatively similar to those seen with 25 mg of psilocybin. The distillate was also rated as producing a stronger overall subjective effect than an equivalent amount of dronabinol.
Interestingly, bumping the dose up to 50 mg didn’t simply make everything “more psychedelic.” That dose produced a different kind of profile, leaning more sedative or dissociative in some cases.
Weed versus Mushrooms: Psilocybin and THC Are Not the Same
The study does not show that THC works in the brain the same way psilocybin does.
Psilocybin is classified as a classic psychedelic, and its effects are strongly tied to serotonin signaling, especially through the 5-HT2A receptor. THC, on the other hand, produces its primary effects through the endocannabinoid system, particularly CB1 receptors.
What the researchers are comparing is not the pharmacology itself. It’s something stranger: the phenomenology of the experience.
Put less academically, two drugs can take very different roads and still end up producing parts of the journey that feel surprisingly similar.
That doesn’t mean it’s going to happen to everybody, either. The sample was tiny, all four participants were white and non-Hispanic, three had postgraduate education and none necessarily represented a typical cannabis consumer. The researchers explicitly acknowledge those limitations.
And again: four people are still four people.
So why pay attention? Because this isn’t the first time researchers have seen something like this.
Cannabis Science Has Repeatedly Wandered Into Psychedelic Territory Before
Back in 2018, also at Johns Hopkins, researchers published a case report involving a 30-year-old man who experienced visual and auditory hallucinations after inhaling vaporized cannabis containing 25 mg of THC in a controlled experiment.
It was an unusual reaction—unusual enough to warrant a case report—but it gave researchers a chance to compare his subjective scores with those seen in experiments involving hallucinogenic substances. They found that some aspects of the experience resembled those reported with drugs like psilocybin, even if the overall picture wasn’t identical.
Then, in 2021, researchers at the University at Albany looked at whether intense cannabis experiences could produce what is known as oceanic boundlessness, a concept used to measure dimensions of mystical experiences such as unity, transcendence and the dissolution of boundaries.
Participants retrospectively described their most intense THC experience. Between 17% and 19% reached levels consistent with what the authors called “breakthrough” experiences. That was well below the 59% reported in certain psilocybin clinical trials, but it showed that this kind of experience could happen with cannabis too.
In 2022, a more controlled study pushed things another step forward. Twenty-five infrequent cannabis users received placebo, 7.5 mg or 15 mg of oral THC.
THC produced dose-dependent changes across several dimensions of altered consciousness. Among other things, it increased a measure called insightfulness, related to the feeling of gaining new understanding, and also increased language entropy, a phenomenon the researchers noted had previously been observed with LSD.
None of those studies argued that cannabis and psychedelics were interchangeable.
But they were all brushing up against the same question.
In 2023, Johns Hopkins researchers essentially pulled those pieces together. In a literature review published online that year and later included in the January 2024 issue of Journal of Psychopharmacology, they examined the ability of cannabis—and THC in particular—to produce perceptual changes, mystical experiences and other phenomena usually associated with classic psychedelics like psilocybin.
Their conclusion was pretty specific: high-THC cannabis may be capable of producing psychedelic effects, but modern experiments may not have picked them up very often because of the doses being used and, especially, the set and setting.
The authors proposed almost exactly what this new study eventually did: giving people high doses of THC under the same kinds of conditions used in therapeutic psychedelic research.
And they had another idea that may be even more interesting: THC could potentially serve as an active comparator in psychedelic clinical trials.
One longstanding problem in these studies is something called functional unblinding. Technically, nobody is supposed to know who got the actual drug and who got placebo. But someone in the middle of a full-blown psychedelic experience can probably make a fairly educated guess that they didn’t get the sugar pill.
And the researcher sitting across from them may be able to guess too.
The authors of the new paper point out that placebos and other comparators used so far often fail for exactly that reason: psychedelic effects are simply too distinctive to easily hide what a participant received.
A dose of THC capable of producing an intense altered state through a different pharmacological mechanism could make the control condition much harder to guess.
For now, that remains a hypothesis. The researchers themselves stress that these four cases are nowhere near enough to establish THC as an ideal active comparator, and they’re calling for systematic studies involving more people and a wider range of doses.
So this finding probably shouldn’t be read as proof that “weed is a psychedelic.”
It does, however, add another clue that the subjective experience produced by THC may be far more variable—and far more dependent on context—than we usually assume.
Change the dose, the expectations, and the setting, and the question gets pretty interesting: How much can a cannabis experience really change?
