Cannabis Help with Anorexia Nervosa? What Research Says

Anorexia nervosa is a serious eating disorder associated with restrictive eating, an intense fear of weight gain and a distorted perception of body weight or shape. The condition can cause severe malnutrition, hormonal disturbances and potentially life-threatening complications. Treatment usually involves specialist psychological therapy, nutritional rehabilitation and regular medical monitoring. Researchers have also investigated whether cannabinoids, particularly THC, could influence appetite and weight gain in people with anorexia nervosa.

Although THC is known to stimulate appetite in certain circumstances, evidence supporting its use in anorexia nervosa remains limited. Increasing hunger does not necessarily address the psychological mechanisms that maintain an eating disorder.

Why Is Medical Cannabis Being Studied for Anorexia?

One of the recognised effects of tetrahydrocannabinol (THC) is its ability to stimulate appetite. Cannabinoid-based medicines have been studied for appetite loss and weight reduction associated with conditions such as HIV/AIDS and cancer.

These effects have encouraged researchers to investigate whether THC might also support weight restoration in patients with anorexia nervosa.

However, anorexia nervosa differs from appetite loss caused by physical illness. People with anorexia nervosa may experience hunger while deliberately restricting food intake because of intense anxiety surrounding eating and weight gain.

For this reason, an increase in appetite alone cannot be assumed to improve the underlying eating disorder.

The Endocannabinoid System and Appetite Regulation

The human body produces its own cannabinoids, known as endocannabinoids. Together with cannabinoid receptors and the enzymes responsible for their production and breakdown, they form the endocannabinoid system (ECS).

This system participates in several physiological processes, including appetite regulation, energy balance, mood and the processing of rewarding experiences.

CB1 receptors, which are found throughout the central nervous system, are involved in the regulation of food intake and responses to food-related stimuli. THC activates these receptors, contributing to its appetite-stimulating effects.

Researchers have investigated whether changes in endocannabinoid signalling are associated with eating disorders, including anorexia nervosa.

What Have Researchers Discovered About the Endocannabinoid System in Anorexia?

Research conducted at KU Leuven in Belgium has provided evidence of differences in cannabinoid receptor activity among patients with eating disorders.

In a 2011 study published in Biological Psychiatry, researchers used positron emission tomography (PET) to examine CB1 receptor availability in patients with anorexia nervosa and bulimia nervosa.

The study found increased CB1 receptor availability in several brain regions among participants with anorexia nervosa compared with healthy controls. The researchers suggested that this might represent an adaptive response to changes in endocannabinoid signalling.

A subsequent Belgian study published in Translational Psychiatry in 2016 investigated the relationship between CB1 receptor availability and body mass index in people with different eating and weight-related disorders.

Researchers identified associations involving brain regions responsible for appetite regulation and food-related reward processing.

These findings suggest that the endocannabinoid system may be involved in the biological mechanisms associated with disordered eating. However, they do not establish whether altered cannabinoid signalling causes anorexia nervosa or whether cannabinoid treatment can improve the condition.

Can THC Make Food More Appealing?

THC can influence the way the brain processes food-related rewards. Activation of CB1 receptors may increase the motivation to eat and affect how rewarding food is perceived.

Experimental research has also suggested that cannabinoid signalling can influence responses to food-related smells and flavours.

These mechanisms may partly explain the increased appetite experienced by some cannabis users.

However, much of the research into cannabinoid-related changes in food perception comes from experimental or preclinical studies. There is insufficient clinical evidence to conclude that THC improves the experience of eating in patients with anorexia nervosa.

Clinical Research: Dronabinol and Weight Gain in Anorexia Nervosa

One of the most frequently cited clinical trials examining cannabinoids in anorexia nervosa was conducted in Denmark and published in the International Journal of Eating Disorders in 2014.

The study involved 25 adult women with severe, long-standing anorexia nervosa. Participants received either placebo or dronabinol, a pharmaceutical form of THC, alongside their existing treatment.

During the four-week treatment period, patients received dronabinol at a dose of 2.5 mg twice daily.

Participants gained approximately 0.7 kg more during dronabinol treatment than during placebo treatment. The researchers reported no significant psychotropic adverse events during the short study period.

However, dronabinol did not produce significant improvements in the psychological symptoms of the eating disorder measured during the trial.

The findings suggest that THC-based medication may influence weight gain in some patients. The small number of participants and short treatment period limit the conclusions that can be drawn about long-term effectiveness and safety.

What Do Scientific Reviews Say About Cannabis and Anorexia?

A systematic review published in 2020 examined clinical research involving cannabinoids in anorexia nervosa. Despite identifying numerous publications, the researchers found only two original randomised controlled trials relevant to their analysis.

The available findings were inconsistent, and the authors concluded that further research was necessary.

A broader review published in the Journal of Eating Disorders in 2023 also identified possible benefits alongside reports of limited effectiveness and potential harms.

More recently, a systematic review and meta-analysis published in The Lancet Psychiatry in April 2026 examined the effectiveness and safety of cannabinoids for several psychiatric conditions.

The analysis found no significant treatment benefit for anorexia nervosa. The evidence specific to this condition remained limited, and cannabinoid treatment was associated with a greater overall risk of adverse events across the psychiatric conditions studied.

These findings do not establish an effective treatment for anorexia nervosa using cannabis or cannabinoid-based medicines.

Can Medical Cannabis Treat Anorexia Nervosa?

Medical cannabis is not an established treatment for anorexia nervosa. There is currently insufficient clinical evidence to recommend it routinely for treating the disorder or achieving sustained recovery.

THC may stimulate appetite or produce modest short-term weight changes under certain conditions, but these effects do not necessarily improve restrictive eating behaviours, fear of weight gain or distorted body image.

Established treatment focuses on restoring nutritional health and addressing the psychological and behavioural factors associated with the disorder.

The UK National Institute for Health and Care Excellence (NICE) recommends specialist psychological treatment and coordinated medical care for anorexia nervosa. Medication should not be offered as the sole treatment.

Any consideration of cannabinoid-based medication in a patient with anorexia nervosa would require careful specialist assessment. Such treatment should not replace established eating disorder care.

What Are the Risks of THC for Patients with Anorexia?

Patients with anorexia nervosa may have physical complications caused by malnutrition, including cardiovascular abnormalities, electrolyte disturbances and reduced physical resilience.

THC can cause dizziness, changes in heart rate, impaired concentration and anxiety. Some individuals may also experience panic reactions or other psychiatric adverse effects.

These risks require particular attention in patients with severe malnutrition, coexisting psychiatric conditions or those taking medications that may interact with cannabinoids.

There is also a risk that short-term appetite stimulation could be mistaken for meaningful improvement in the underlying disorder. Clinical progress requires assessment of nutritional status, eating behaviours and psychological symptoms over time.

When Might Cannabinoid Treatment Be Considered?

There is currently no well-established clinical indication for prescribing medical cannabis specifically to treat anorexia nervosa.

In unusual circumstances, a specialist may assess whether a cannabinoid-based medicine has a separate, justified medical indication in a patient who also has an eating disorder. Such decisions require an individual evaluation of potential benefits, contraindications and interactions with existing treatment.

The available research does not support using THC as a substitute for nutritional rehabilitation, psychological therapy or psychiatric care.

Patients experiencing symptoms of anorexia nervosa should seek assessment from healthcare professionals experienced in eating disorders. Early treatment can reduce the risk of serious medical complications.