Cannabidiol (CBD), a compound derived from marijuana, could move closer to clinical trials for potentially helping to treat or prevent COVID-19, according to researchers. More research is required to test its overall effectiveness.

Dr. Marsha Rosner of the University of Chicago led a research team that prescribed 1,212 patients with epilepsy an oral high-purity CBD dose of 100 mg/mL which showed they tested positive for COVID-19 at lower rates than the control group who didn’t take CBD. The research showed 6.2% of patients tested positive for the virus after taking CBD compared to the 8.9% of control group patients who did not use CBD.

The research first treated human lung cells with a dose of CBD before exposing them to COVID-19 and monitoring them for the virus. Researchers also gave CBD to mice one week before infecting them with COVID and both times found that the CBD suppressed infection in both cases.

“A clinical trial is necessary to determine whether CBD is really effective at preventing or suppressing SARS-CoV-2 infection, but we think this may have potential as a prophylactic treatment,” Rosner said in a news release.

Researchers caution against self-treating with “non-medical CBD” such as edibles or inhalants as a preventative treatment against the virus if someone tests positive or is unvaccinated. Rosner says buying CBD-infused gummy bears or muffins “probably won’t do anything.” The CBD that was tested was 98% pure and Rosner stresses “you want the lowest possible effective dose,” because of potential side effects as the drug is filtered through the liver.

"We would love to be able to say specifically" that a certain dose of cannabinoids is helpful, she said, but at this point, "vaccine-induced antibodies and antibody drugs are much more effective at blocking infection," Rosner said.

Dr. Amesh Adaija said that “this is an early study that needs further confirmation but does provide a pathway for new ways to help combat COVID-19," adding further studies on CBD will be needed to further explore Rosner’s findings.