The most misleading phrase in “psychedelic nasal spray” may be “nasal spray.” In a newly published trial, the treatment was not taken at home or used like an ordinary prescription. It was delivered by a clinician in a carefully prepared room, with psychological support, a physician nearby and hours of monitoring. The spray was brief; the treatment system around it was not.
That distinction matters because the study addresses one of psychedelic medicine’s practical bottlenecks. Psilocybin and LSD sessions can occupy a clinic for much of a day. Mebufotenin—also known as 5-MeO-DMT—produces a much shorter acute psychedelic experience. The question is whether shortening that experience can preserve a meaningful antidepressant effect while reducing the burden on patients and services.
The phase 2b randomized trial, published in *JAMA* on October 26, 2026, offers an encouraging but not definitive answer.
One dose produced a measurable difference at day 29
Researchers enrolled 193 adults whose moderate-to-severe major depression had not responded to two to five antidepressant treatments in the current episode. At 38 sites in Australia, Europe and the United States, participants received a single intranasal dose of mebufotenin benzoate: 8 milligrams, 12 milligrams or a 0.3-milligram low-dose comparator. Everyone also received manualized psychological support before, during and after dosing.
The primary comparison was between 12 milligrams and the low dose after 29 days. On the clinician-rated Montgomery–Åsberg Depression Rating Scale, which runs from 0 to 60, scores fell by an average of 11.1 points in the 12-milligram group and 5.5 points in the comparator group. The adjusted difference was 5.3 points, with a 95% confidence interval from 1.8 to 8.9 points in favor of the active dose.
The 8-milligram group showed a similar adjusted advantage of 6.2 points. At day 29, about 34% of participants in each active-dose group met the study’s definition of response, compared with 12% in the low-dose group. Remission rates were 26% for 8 milligrams, 18% for 12 milligrams and 8% for the comparator. Differences in depression ratings were reported from the next day through the final assessment at day 57.
Those are clinically relevant signals, not proof of a finished treatment. The lower active dose performed at least as well numerically as the higher one, and the 8-milligram group was smaller after the trial’s randomization ratio was changed during recruitment. The authors selected 8 milligrams for phase 3 evaluation partly because it appeared to offer a better balance of efficacy and tolerability. The JAMA research summary explicitly says confirmation in phase 3 trials is needed.
A short experience still required a clinical system
The treatment itself was a single spray into one nostril. Participants were assessed for discharge readiness beginning 90 minutes later, and most in the active groups met those criteria within two hours. Yet the protocol did not permit anyone to leave before four hours. The dosing took place in a private room with a trained clinician, psychological support and a physician close by. Some participants also stopped existing antidepressants under supervision at least two weeks beforehand.
So the innovation is not a self-administered antidepressant. It is the possibility of fitting a supervised psychedelic intervention into a shorter clinic session than longer-acting compounds require. That could matter for staffing, cost and access, but this trial did not measure those outcomes directly.
Adverse events were common in every group: 76% with 8 milligrams, 85% with 12 milligrams and 73% with the low dose. Almost all events were mild or moderate, most often headache, nausea or pain at the administration site. One participant in the 12-milligram group had two severe panic attacks judged related to treatment. Temporary increases in heart rate and blood pressure resolved within an hour. These results describe screened participants in a controlled setting; they do not establish safety outside it.
The findings also sit beside an earlier 81-person randomized trial of inhaled mebufotenin, which reported symptom improvement over placebo. The new study is larger and follows participants longer, but both remain mid-stage trials rather than evidence of routine clinical effectiveness.
Blinding remains the hardest test
Psychedelic trials have an unusual placebo problem: participants and clinicians can often tell who received the active treatment. The researchers used a subperceptual dose as the comparator and kept independent depression raters blinded. Even so, both participants and clinicians largely guessed assignment correctly. Expectations and the experience of being visibly altered can influence symptom reports, care interactions or both. Independent raters reduce that risk but cannot erase it.
Other limits narrow the conclusion. The sample lacked broad ethnic diversity and may underrepresent people with more severe treatment resistance. Antidepressant washout may not resemble future practice. The study could not isolate the contribution of psychological support. It was funded by Beckley Psytech, now part of AtaiBeckley; sponsor employees participated in the design, data work, interpretation and manuscript process. The trial was registered as NCT05870540, which helps make its prespecified design inspectable but does not remove those conflicts.
The result therefore supports a precise claim: under close supervision, a single short-acting psychedelic dose produced a larger reduction in depression ratings than a very low dose for up to eight weeks. It does not show that a nasal spray is ready for home use, that psychological support is dispensable or that blinding no longer matters. The real promise is narrower—and potentially important: a psychedelic treatment may not need an all-day altered state to produce a lasting clinical signal.
