An FDA-Approved CBD Drug Was Tested on Anorexia Patients. They Gained Weight. Getting It Will Still Be Hard.

Anorexia nervosa kills more people than any other psychiatric condition. It has exactly one FDA-approved drug for weight restoration — an antipsychotic called olanzapine, green-lit in 2021 — and it works for only a fraction of patients. Against that backdrop, a small but rigorous new clinical trial from the University of Southern California and UC San Diego just produced a result that researchers and eating disorder clinicians are paying close attention to: an FDA-approved, plant-derived CBD formulation helped women with anorexia gain weight in a placebo-controlled setting.

The drug is Epidiolex. Most people know it, if they know it at all, as the first cannabis-derived medicine the FDA ever approved — cleared in 2018 for two rare childhood epilepsies, Dravet syndrome and Lennox-Gastaut syndrome. What most people don’t know is that its active ingredient, pharmaceutical-grade cannabidiol derived directly from the cannabis plant, has been studied for other conditions ever since. Appetite and weight regulation — long associated with cannabis — have been in researchers’ sights for years. This trial is the first placebo-controlled test of CBD’s specific effect on anorexia nervosa weight recovery.

What the Study Found

Researchers enrolled 32 women diagnosed with anorexia nervosa or atypical anorexia nervosa in a double-blind, randomized controlled trial. Half received twice-daily doses of Epidiolex; half received a placebo. The trial ran for three weeks.

The results, published in the International Journal of Eating Disorders, were significant: participants who received CBD showed “a significant increase in BMI over time compared to the placebo group.” Critically, they reported no serious side effects — a meaningful finding in a population where treatment tolerability is frequently a barrier to sticking with any protocol.

The study’s authors were measured but clear about what they found. CBD demonstrated “a favorable safety profile” and “the capacity to support weight recovery” in these patients, with indications it may also be improving eating disorder psychopathology — meaning patients’ psychological relationship with food and body image, not just the number on the scale. They called for larger, longer trials to “make definitive conclusions about the mechanism through which CBD impacts AN pathophysiology.”

Why This Matters

Anorexia nervosa carries a crude mortality rate estimated between 5 and 10 percent. Death from cardiac failure and organ damage secondary to starvation, along with suicide, are both significant contributors. For patients who have cycled through treatment programs, residential care, and medication regimens without adequate results, a new evidence-supported option is not an abstraction. It’s potentially life-changing.

But this trial is also a window into how thin the treatment toolkit actually is. Olanzapine — the only FDA-approved pharmaceutical for weight restoration — is an antipsychotic with side effects that include metabolic changes, sedation, and extrapyramidal symptoms. For many patients, particularly young women who are already hyperaware of bodily control, it’s a hard sell. Nutritional counseling and cognitive behavioral therapy are the first-line treatments and can be genuinely effective, but dropout rates are high and long-term recovery outcomes remain mixed across the population. The field has been hungry for new tools for a long time.

A plant-derived compound with a clean enough safety profile to pass a controlled trial, showing real weight recovery outcomes, is exactly the kind of data the field needs. Which makes the access problem harder to ignore.

The Access Problem

Epidiolex is not a cheap drug. A one-month supply typically runs between $1,300 and $2,700 at retail, depending on dosage and pharmacy. Insurance coverage exists but is frequently contested — and its FDA-approved indications are narrow. Epidiolex is approved for epilepsy and, since 2020, tuberous sclerosis complex. Using it for anorexia nervosa is off-label: legal for a physician to prescribe, but a harder insurance fight, a tougher prior-authorization hurdle, and a more expensive out-of-pocket path for patients who are already dealing with a condition that consumes enormous financial and emotional resources.

That’s before factoring in the broader political environment surrounding cannabis medicine. Epidiolex may be a federally approved pharmaceutical, but CBD derived from any other cannabis source remains a Schedule I controlled substance — the same classification as heroin. The research that produced this trial exists because the scientists were working with the one CBD product federally sanctioned for that kind of human research. Any follow-up study involving other cannabinoid formulations, or attempting to compare CBD to plant cannabis extracts, requires DEA licensing, restricted supply chains, and layers of institutional review that weren’t designed to facilitate cannabis research at scale.

In practice, that means the trials that could move this science forward are slower, more expensive, and more prone to abandonment than equivalent pharmaceutical research. The federal regulatory architecture, in short, is actively working against the science here.

What’s Next — and What Came Before

This isn’t the first time cannabis and appetite disorders have intersected in the research literature. A 2018 study — also summarized by NORML — found that low-dose oral THC was “safe and effective at treating symptoms of anorexia,” showing improvements in psychological symptoms including anxiety and depression around food. THC and CBD work through different mechanisms in the body, and comparing them directly isn’t straightforward; what this newer trial adds is a controlled, blinded design and a primary focus on BMI as an outcome measure, not just symptom scores.

The authors of the Epidiolex study explicitly called for next steps: larger samples, longer durations, and investigation into whether combining CBD with other interventions — specific dietary protocols, for instance — could amplify outcomes. That’s a responsible scientific posture for a pilot trial of 32 participants.

But patients don’t wait in a holding pattern while research methodologies mature. There are an estimated one million people in the United States living with anorexia nervosa or related eating disorders, with disproportionate concentration among adolescent and young adult women, as well as growing recognition of the condition in populations historically excluded from treatment studies. They are not going to line up at their physicians’ offices demanding Epidiolex prescriptions based on a three-week pilot. But they, and their doctors, deserve to know this data exists — and to understand that the obstacles between that data and broader therapeutic access are not scientific. They are political.

The Bottom Line

The USC/UCSD trial is a small study, and the authors say so explicitly. It is not a mandate for prescribing. It is, however, a clear signal that CBD’s therapeutic range extends well beyond the epilepsy conditions that got Epidiolex onto pharmacy shelves.

For the eating disorder community, for researchers, and for anyone paying attention to what cannabis medicine might still do if federal barriers were lower, it’s a data point worth paying attention to. A drug that helps people with one of the most dangerous psychiatric conditions in the country gain weight, with no serious side effects, and made from a plant that remains classified as having “no accepted medical use” under federal law — that’s not a niche finding. That’s the contradiction the drug war left us with, still playing out in a hospital somewhere right now.

Maya Torres covers the human side of cannabis policy for CannabisInquirer.com — expungement, medical access, and equity. Reach her at mtorres@cannabisinquirer.com.