In brief
- A pilot trial at Imperial College London tested psilocybin with therapeutic support in 21 women with long-term anorexia nervosa (average duration of 11 years).
- 86% showed symptom improvement at two weeks, and 48% reached scores comparable to people without an eating disorder at three months. Symptom follow-up reached six months and motivation follow-up one year.
- Without a control group, the design cannot separate psilocybin effects from therapeutic support and usual care, or equate improved scores with recovery.
A team at Imperial College London has published the results of a pilot trial in which synthetic psilocybin, combined with intensive therapy, was administered to women with anorexia nervosa who had been ill for an average of eleven years without finding a long-term effective treatment. The study, published on July 8, 2026, in the British Journal of Psychiatry, is small and lacks a control group, but it opens an almost unexplored avenue of research: the vast majority of psilocybin trials have focused on depression or post-traumatic stress disorder, not eating disorders.
A six-week protocol for a decade-long illness
The study included 21 adult women with an average age of 32 and an average body mass index of 16.4 (below the healthy threshold of 18.5). The protocol, led by researcher Hannah Douglass alongside the team of Robin Carhart-Harris and David Erritzoe, consisted of three dosing sessions separated by two weeks: the first with 1 mg as a reference dose, which some participants did notice, and the following two with 25 mg each. Each session was accompanied by hours of therapeutic conversation before and after, led by psychotherapist Jennifer Danby, who specializes in eating disorders. Participants were blinded to the dosage they received at any given time.
Symptoms at six months and motivation at one year
Two weeks after the final session, 18 of the 21 women (86%) showed improvement in their eating disorder symptom scores. At three months, 48% presented values comparable to those of people without a diagnosis. At six months, the effect remained, and at one year, participants reported maintaining greater motivation to pursue recovery, although body weight barely changed during the six weeks it was measured. The most common adverse effects were headache and nausea. One participant experienced two suicide attempts at seven and nine months and required hospitalization. The team judged them unrelated to the intervention; that assessment does not establish the absence of risk in this small, clinically vulnerable sample. Another participant dropped out of the study after the second dose.
What this implies
The pilot cannot attribute improvement specifically to the substance: psychological support and usual care accompanied dosing, without an independent control group. The sample size and lack of a control group limit generalization of the findings. Imperial reports that the authors call for larger, more rigorous studies and emphasize professional support in any serious discussion of harm reduction with psychedelics: in complex clinical presentations like this, support must be provided by trained clinicians in a supportive environment, not improvised. Anorexia nervosa has one of the highest mortality rates among mental disorders, and a significant portion of those who suffer from it chronically do not respond to available treatments, which explains the interest in exploring alternatives, including less conventional pharmacological ones, without presenting them as a definitive solution or minimizing the risks for an especially vulnerable clinical population.
Source
- Imperial College London. Psilocybin therapy shows potential as a treatment for anorexia nervosa in small trial. Imperial College London News, 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.
