In brief
- A pilot study from the Centre for Psychedelic Research at Imperial College London tested psilocybin in 21 women with long-standing anorexia nervosa (average duration of 11 years).
- 18 of the 21 participants showed improvements two weeks after the final session, and 48% reached symptom scores comparable to those of people without the disorder at the three-month mark.
- Motivation for recovery remained high for one year, although body weight did not change significantly during the six weeks of treatment.
A team from the Centre for Psychedelic Research at Imperial College London has published results in The British Journal of Psychiatry from a pilot study exploring psilocybin, combined with psychological support, as a potential avenue for people with anorexia nervosa—an eating disorder notoriously difficult to treat with current therapies.
A group often excluded from trials
The 21 female participants, with an average age of 32, had been living with anorexia nervosa for an average of eleven years and had not found lasting improvements with previous treatments. This profile of chronic, treatment-resistant cases is typically excluded from conventional clinical trials, which gives this work added value despite its small size. The authors themselves describe it as an open-label pilot study, without a control group, designed to explore feasibility and safety rather than to establish definitive efficacy.
Three doses and one-year follow-up
Each participant received three oral doses of psilocybin over a six-week period, with two weeks between sessions: an initial low dose of 1 mg and two subsequent doses of 25 mg, provided within a supportive therapeutic environment featuring structured conversation before and after each session. According to Imperial College London, the substance was well tolerated by all participants, with headache and nausea being the most frequent side effects. Two weeks after the final dose, 18 of the 21 women showed improvements; at three months, 48% presented eating disorder symptom scores comparable to those of people without the diagnosis, and motivation for recovery remained high after one year. Body weight, however, did not change significantly during the six weeks of active treatment.
What this implies
The researchers themselves, including Hannah Douglass and Robin Carhart-Harris, urge caution: this is a small study without a comparative placebo group and without demonstrated weight changes, so they describe the results as “promising” and justifying larger, more rigorous trials, rather than a validated therapy. They also stress that this type of intervention requires specifically trained clinicians and a sustained support environment, given the delicate nature of the clinical presentation. For those following psychedelic research, the relevant finding is that it opens a new line of work for a disorder where current therapeutic options are limited, with a one-year follow-up suggesting that the effect on motivation for change could be more durable than in other approaches.
Source
- Douglass, H. M., Spriggs, M. J., Godfrey, K. et al. Psilocybin therapy for adult females with anorexia nervosa: pilot study. The British Journal of Psychiatry, July 8, 2026.
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.
