Under a double-blind, placebo-controlled, within-subject crossover design, four healthy adults received placebo, 25 mg psilocybin, and 25 mg oral THC on separate sessions, with THC given in two forms: synthetic dronabinol and a whole-plant cannabis distillate extract that was 89.9% THC. Two of the four participants also completed an additional 50 mg THC session.

The authors report that 25 mg oral THC, in both its synthetic and whole-plant forms, yielded a subjective experience similar to 25 mg psilocybin. Notably, when asked afterward what drug they believed they had received, both a psychedelic-naive and a psychedelic-experienced participant mistook dronabinol for a classic hallucinogen.

This study’s defining feature is that it tested THC inside the exact expectancy (set) and context (setting) conditions used in classic psychedelic clinical trials, rather than a standard cannabis-pharmacology lab session. That choice is deliberate: psychedelic researchers have long argued that context shapes subjective drug effects as much as pharmacology does, and this trial was designed to test whether that same context could pull a psychoactive but non-classically-hallucinogenic drug like THC toward a psilocybin-like experience.

Because the same standardized session structure was used across all four conditions, placebo, psilocybin, and both THC formulations, the comparison is a more controlled test of set and setting’s role than most real-world reports of high-dose cannabis experiences allow.

The study directly compared a single-molecule synthetic THC product (dronabinol) against a whole-plant cannabis distillate extract standardized to 89.9% THC, at the same 25 mg THC dose. The authors report that both forms produced subjective effects similar to psilocybin at that dose, which is a preliminary point of interest for the ongoing debate over whether whole-plant cannabis products behave meaningfully differently from single-molecule THC at matched doses.

The brief report does not describe formal statistical comparisons between the two THC formulations, consistent with a pilot study of this size, so this should be read as an observation to test further rather than a settled equivalence claim.

The authors are explicit that these are preliminary findings limited by sample size, and a study of four participants cannot support statistical inference about how reliably or how strongly high-dose THC mimics psilocybin across a broader population.

What this pilot does offer is a rigorously controlled first look, using validated psychedelic-trial methodology, at a question that has mostly been addressed through case reports and informal accounts of high-dose cannabis experiences. That combination of small sample and methodological rigor is exactly what a hypothesis-generating pilot study is meant to provide, a reason to run a larger, adequately powered trial, not a reason to draw firm clinical conclusions yet.

This pilot sits within a broader research effort to understand why some patients report unexpectedly intense, sometimes psychedelic-like reactions to high-dose oral THC, particularly from edibles or dronabinol, reactions that emergency clinicians have traditionally framed as cannabis-induced anxiety or panic rather than a distinct psychedelic-like phenomenon.

It also speaks to an active methodological question in psychedelic-therapy research: functional unblinding, where participants and researchers can often guess treatment assignment from subjective effects alone, undermining placebo-controlled trial design. A drug that can mimic a classic hallucinogen’s subjective profile, like high-dose THC apparently can under the right conditions, is relevant both as a potential active-placebo comparator and as a caution about how easily expectancy can shape reported experience.

What strikes me most about this pilot is not the finding itself, that very high doses of oral THC can feel disorienting or hallucinogen-like, which many patients and clinicians have already observed anecdotally, but the fact that a Johns Hopkins psychedelic-research team took that anecdotal pattern seriously enough to test it formally, with the same rigor they’d apply to a psilocybin trial. That is exactly the kind of bridge-building between cannabis medicine and psychedelic medicine I would like to see more of.

Clinically, I read this as reinforcement of something I already counsel patients on: high-dose oral THC, whether prescribed dronabinol or a strong edible, is not a mild or purely relaxing experience for everyone, and patients should be dosed cautiously and warned honestly about what an intense reaction can feel like. I would not extrapolate from four participants to any claim about THC substituting for psilocybin therapeutically, but I do think this justifies a larger, adequately powered follow-up before anyone tries to draw firmer conclusions.

Four distinctions worth keeping straight