In brief
- A pilot trial with ten women shows that a GH001 session with one to three individualized inhalations reached MADRS remission criteria two hours after the final dose, with the effect sustained at least through the eighth day.
- The study, published in The Journal of Clinical Psychiatry, is—according to its corresponding author—the first published clinical trial evaluating a psychedelic-based therapy specifically for postpartum depression.
- This is an open-label trial without a comparison group and with only ten participants: the results are promising but preliminary, and the company is already preparing larger randomized trials.
Ten women with postpartum depression received one GH001 session with one to three inhalations according to response, a drug developed by the Irish company GH Research from 5-MeO-DMT, and all ten met the MADRS remission threshold, which does not mean absence of every symptom within hours. The results, published on June 3, 2026, in The Journal of Clinical Psychiatry, represent the first clinical data released on a psychedelic compound applied specifically to this form of depression, which affects a significant percentage of women after childbirth.
A single session, eight days of follow-up
The phase 2a trial was open-label—all participants knew they were receiving the active drug—and lacked a placebo group. The ten women inhaled GH001, also known by its generic name mebufotenin, in a single-day supervised session. Scores on the Montgomery-Åsberg Depression Rating Scale (MADRS) dropped by an average of 35.4 points between the start of the study and the eighth day (p<0.0001), and all ten participants met the criteria for remission—a MADRS score of 10 or less—two hours after the final administration that day, an effect that remained stable throughout the week of follow-up. The scale measuring maternal functioning (Barkin Index) also improved, with an average increase of 56%. No serious events were reported; three women had suicidal ideation at baseline and none at subsequent assessments, reported effects were mild or moderate, consistent with what has been described for 5-MeO-DMT in other depression trials.
Breastfeeding and next steps
As part of the study, drug levels in breast milk were also analyzed. According to the company, the data support a strategy involving a brief interruption of breastfeeding around the time of dosing, rather than prolonged suspensions, a hypothesis based on four lactating women, without demonstrating infant safety or establishing a use regimen here. Researcher Kristina M. Deligiannidis, a signatory of the study, described the work as “the first published clinical trial of a psychedelic-based therapy specifically for postpartum depression.” The data were also presented at the CINP 2026 congress, held in Glasgow at the end of June, alongside broader results for the same drug in treatment-resistant depression, an indication for which GH001 is already in the phase of preparing larger pivotal trials.
What this implies
Postpartum depression is usually treated with slow-acting antidepressants and specific options include oral zuranolone; the paper describes brexanolone as previously approved and withdrawn from the market. A possible single-session intervention with effects in hours would represent a significant change for many women and their families. That said, it is important not to lose sight of the study size: ten people, without a comparison group, is a sample too small to rule out that part of the improvement is due to the effect of expectation or the clinical support received during the session, which is especially relevant with substances of intense and brief psychoactive effect like 5-MeO-DMT. The company itself treats this as a preliminary signal and announces larger randomized, controlled trials as the next step. As with the rest of psychedelic research, interest is not at odds with caution: the data are encouraging, but there is still a long way to go to know if this benefit holds up in larger and more diverse populations.
Source
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
