Source: Cubała et al., JAMA Psychiatry 2026 (doi:10.1001/jamapsychiatry.2026.0096)

This is one of the most important 5-MeO-DMT studies to date. It's a randomized, double-blind, placebo-controlled trial, the gold standard design, published in a leading psychiatry journal. It tested GH001, GH Research's inhaled synthetic 5-MeO-DMT, in people whose depression hadn't improved with standard antidepressants.

The study

Design: Phase 2b. A 7-day randomized, double-blind, placebo-controlled phase, followed by a 6-month open-label extension.
Where and when: 16 sites across Europe, May 2023 to March 2025.
Participants: 128 people were assessed and 81 were randomized: 40 to GH001 and 41 to placebo. All were adults aged 18-64 with treatment-resistant depression, meaning no response to 2-5 antidepressant treatments, in a current episode lasting 2 years or less. Average age was about 42-44, and a little over half were women.
Dosing: up to three escalating inhaled doses (6, 12 and 18 mg) on a single day, or a matching placebo regimen. In the GH001 group, 9 people received one dose, 21 received two, and 10 received all three.
Main measure: change in depression score (MADRS) from baseline to day 8, assessed by raters who didn't know who received what.

What it found

Depression scores: GH001 lowered scores by about 15.5 points more than placebo by day 8, a large and statistically significant difference.
Remission: 57.5% on GH001 (23 of 40) versus none on placebo.
Response: 60% on GH001 (24 of 40) versus none on placebo.
Other measures: secondary measures of illness severity also favoured GH001.
The placebo group: in the open-label extension, all 41 placebo patients then received GH001 and responded at similar rates.
Six months later: of the 23 people in remission at day 8, 3 were still in remission without any further treatment. No one developed tolerance to the effect over the six months.

Safety

Side effects: these occurred in 72.5% of the GH001 group versus 7.3% on placebo. All were mild or moderate, most often nausea, extra salivation and tingling sensations.
During the blinded week: no severe or serious adverse events, and no one stopped because of side effects.
Mental health: no new suicidal thoughts and no psychotic symptoms. Dissociation didn't persist once the effects wore off.
Over six months: no serious treatment-related adverse events.

Limitations

Still a modest sample, which limited analysis of subgroups
Few participants had very long-standing or highly resistant depression
With a medicine this powerful, most people can probably tell whether they received it, which makes true blinding difficult
Sponsored by GH Research

What this means, and doesn't

A placebo-controlled result of this size is much harder to explain away than a small open-label study, and it marks a genuine step forward for the field. The six-month figure is an important reality check, though. For most people, the improvement faded without further sessions. Larger Phase 3 trials, including in the United States, will show whether these results hold.

The finding also supports a principle long held in ceremonial practice: a single powerful experience can open a door, but lasting change usually depends on what happens afterwards. That's the role integration is meant to play.

This was a clinical product given in a medical setting for a diagnosed condition. It doesn't describe ceremonial work, and it isn't a reason to stop any current treatment.

Research summaries are for education, not medical advice. Considering 5-MeO-DMT yourself?
Start with Safety & Screening.