New research found cannabidiol (CBD) effectively blocks SARS-CoV-2 replication in human cells. The study was published Thursday in the peer-reviewed journal Science Advances.
A team of 33 researchers at the University of Chicago and the University of Louisville found people taking 100 milligrams-per-milliliter of high-purity CBD returned positive COVD-19 tests at a lower rate than control groups who did not take CBD.
Research was conducted on three different groups: humans, human lung carcinoma cells, and mice.
Scientists hoped to determine if the cannabinoid would regulate the antiviral inflammatory response.
Initially, researchers pretreated lung cells with CBD two hours prior to infection with the virus.
After 48 hours, researchers found “CBD potently inhibited viral replication under non-toxic conditions.”
The study went on to test three SARS-CoV-2 variants and concluded their ability to infect cells was also inhibited by CBD.
Combining CBD with THC at a one-to-one ratio suppressed the efficacy of CBD in combating the virus.
Trials were then conducted with mice to determine if an equivalent effect could be found. Mice were treated with CBD for a week before being exposed to SARS-CoV-2. They were then treated for an additional 4 days with CBD.
The findings provided an important insight into the cannabinoid’s effectiveness. “CBD treatment significantly inhibited viral replication in lungs and nasal turbinates … During this period, the mice showed no signs of clinical disease,” the study stated.
“These results establish the pre-clinical efficacy of CBD as an anti-viral drug for SARS-CoV-2 during early stages of infection.”
Finally, researchers analyzed 1,212 patients from the National COVID Cohort Collaborative.
Patients with medically-similar backgrounds were selected for the study.
The research team chose individuals with a history of seizure-related conditions, and subdivided them into those using CBD to treat their symptoms and those who did not use CBD.
Patients using high-potency CBD had significantly lower COVID-19 infection rates than patients from the non-CBD control group.
“Our results suggest that CBD and its metabolite 7-OH-CBD can block SARS-CoV-2 infection at early and even later stages of infection,” the study stated.
This research adds to other recent studies linking cannabis to treatment for the novel coronavirus.
While these findings are clinically significant and a vital step in furthering the fight against COVID-19, the study’s authors advise against using non-medical formulations of CBD as a preventative or treatment therapy at the present time.