Psilocybin Shows Promise for Treating Anorexia

A new clinical trial offers early – but certainly promising – insights into the potential benefits of psilocybin to treat anorexia nervosa.

The open-label study, which included 10 adult women diagnosed with anorexia or in partial remission, administered a single 25-mg dose of synthetic psilocybin, the psychoactive compound in some mushrooms. The researchers paired the drug with psychological support. 

Initial results suggest the treatment might be safe and tolerable, with some participants experiencing noteworthy symptom relief.

“Our findings suggest that psilocybin may be helpful in supporting meaningful psychological change in a subset of people with anorexia nervosa,” lead author Stephanie Knatz Peck, MD, explained. “What’s particularly interesting is that 60 percent of participants reported a reduction in the importance of physical appearance, while 70 percent noted quality-of-life improvements and shifts in personal identity.”

Trial Background and Setup

Anorexia nervosa remains one of the most troubling – and difficult to treat – mental health conditions, with a mortality rate 18 times higher than that of the general population. Distorting one’s relationship between food and body image, anorexia typically spawns severe health problems.

To make things worse, there are no FDA-approved medications on the market designed to treat anorexia, which makes novel treatment approaches critical.

The trial sought to evaluate psilocybin’s safety and acceptability as a therapeutic tool. To explore the safety and tolerability of psilocybin within this vulnerable group, researchers also monitored the participants’ heart function, vital signs, and blood work, while keeping an eye on their mental health markers.

Key Findings

Primary trial results showed encouraging safety outcomes. None of the participants experienced serious adverse events. And the researchers observed no significant changes in heart function, vital signs, or suicidal ideation.

And while two participants developed mild hypoglycemia — low blood sugar, which resolved within 24 hours — the research team suggested it probably stemmed from the fasting participants had to endure for the trial, rather than the psilocybin itself.

The side effects that did crop up appear to be generally mild, including headaches, nausea, and fatigue.

Participants also reported meaningful results from the treatment, with 90 percent of them saying it improved their outlook. Notably, many reported that a single session wasn’t enough, suggesting that multiple treatments would be needed.

“You are able to act in a way that maybe had felt unachievable before if you set the right intention,” one participant said.

But perhaps most importantly, the trial managed to keep everyone engaged, with no participants dropping out.

Exploratory Results

Specifically, the researchers noted that:

• Four of the 10 participants showed clinically significant reductions in eating disorder symptoms three months into the treatment.
• Some reported improvements in flexibility around food-related concerns and a reduced preoccupation with body shape and weight.
• And 40 percent of participants demonstrated scores in the “normal” range on the Eating Disorder Examination, suggesting a reduction in disorder severity. 

Although researchers couldn’t document any notable body mass index (BMI) changes in the group, individual results varied. Some participants gained weight, while others remained stable, or even lost a few pounds. This variation suggests that psilocybin’s impact could be more psychological than physiological, at least in the short term.

Why Psilocybin Might Work

Psilocybin’s potential benefits could stem from its influence on the brain pathways linked to serotonin. Many anorexia patients live with abnormalities in their serotonin pathways, which might make them especially responsive to therapies that address this system.

Earlier research suggests that psilocybin might enhance brain plasticity, which could help anorexia patients embrace better perspectives on food, body image, and self-worth.

The trial’s psychological support component probably helped. Psilocybin therapy generally involves guidance from trained therapists to help patients process their experiences. The safe setting and therapeutic approach might have contributed to the participants’ positive perceptions of the treatment and the mindset changes some of them described.

Future Directions

While the researchers concede that this early-stage study is too small to make any sweeping claims, it helps lay the foundation for future investigation.

In fact, two larger trials are already underway to further explore psilocybin’s effects on eating disorders. If they can confirm that psilocybin can meaningfully address anorexia symptoms, it could pave the way for the first FDA-approved pharmacological treatment.

But for now, psilocybin remains a promising – albeit unproven treatment option.

Further Reading

Recovery from Anorexia and Bulimia

Eating Disorders and Reproductive Health

Eating Disorders in Youth With Bipolar Disorder