Researchers are studying how psilocybin might affect obesity, based on growing evidence.

Past research on psilocybin, as well as other psychedelics, has consistently shown the drug may be effective in treating mental conditions such anxiety, depression, PTSD, or addiction. A correlational study that was published in 2013 found that people who had tried classic psychedelic drugs at least once over their lives were significantly less likely to be overweight.

Researchers from Denmark’s University of Copenhagen conducted a new experiment using mice to test the ability of psilocybin in reducing food cravings. The researchers tested psilocybin’s effects on food intake and body weight using mice models of diet-induced and genetic obesity.

Initial research showed that mice with obesity who received psilocybin had no weight loss or food intake after receiving a high-dose dose or daily microdosing. Although the researchers did not discover any evidence supporting the hypothesis they found it encouraging and they encouraged further research.

“We were surprised to see that psilocybin did not have at least a subtle direct effect on food intake and/or body weight in genetic and diet-induced models of obesity and overeating,” study author Christoffer Clemmensen, an associate professor at the University of Copenhagen, told PsyPost. “Although we failed to discover major effects of psilocybin on mouse energy metabolism and behaviors associated with eating, we believe that there are nuances of the mode of action of psychedelics that cannot be appropriately captured in rodent models. Importantly, psilocybin was safe and had no adverse effects on the physiological parameters we tested in mice.”

In the United States, obesity is common and costly

The Centers for Disease Control and Prevention data shows that obesity has been identified as one of the top health issues in the United States. In fact, it affected almost 42% of Americans between 2017 and 2020. Obesity prevalence among Americans aged 20-39 years was 39.8%, 44% among those 40-59 year olds, and 41% among people 60 and older.

Heart disease, stroke and type 2 diabetes are some of the most common causes of premature, preventable death. In 2019, the annual medical cost of obesity was $173 billion, which adds approximately $1861 per person.

“Perhaps surprisingly, obesity is a rather treatment resistant disease that shares neuropathological similarities to mental disorders, such as addiction,” said Clemmensen.

“Dysfunctions in homeostatic and reward circuitry can lead to ‘relapse’ in people with obesity, making it difficult to adhere to lifestyle and even drug interventions. Given that psychedelics are thought to enhance the plasticity of neural circuits, it may be that when combined with behavioural therapy, psychedelics might be powerful tools for ‘resetting’ long-held compulsive behaviors. Further, classic psychedelics act on the serotonergic system, and could have a direct effect on food intake by broad activation of serotonin (5-HT) receptors, emphasizing their potential benefits for obesity.”

They noted that mice models can be used to study scientific issues, but they aren’t a substitute for humans. Therefore, the researchers encouraged research on how psilocybin could affect weight and food intake.

“The main caveat is translation,” Clemmensen said. “Although animal models in general have been invaluable for neuroscience and metabolism research they might be inappropriate for testing health benefits of psychedelics.”

“I remain excited about this topic, psychedelics for treatment of obesity and eating disorders and I think we should start considering what sub-groups of patients could benefit from this drug class,” he added.

The study, “Acute and long-term effects of psilocybin on energy balance and feeding behavior in mice,” was published last month by the peer-reviewed journal Translational Psychology.