A University of Chicago study published in Science Advances found that cannabidiol (CBD), a non-psychoactive cannabis compound, blocked SARS-CoV-2 replication in human lung cells and mice. These preliminary findings warrant caution and further research.
SARS-CoV-2, the virus behind COVID-19, is the seventh known human coronavirus, joining SARS-CoV, 229E, NL63, OC43, HKU1, and MERS-CoV. These viruses range from mild colds to severe illness. Even with vaccines available, ongoing spread underscores the need for new treatments.
Few therapies effectively block SARS-CoV-2 replication, making this research noteworthy. The study shows CBD inhibits SARS-CoV-2 infection in lab-grown human cells and mice.
Viruses like SARS-CoV-2 hijack host cells to replicate their genetic material and proteins. Led by Dr. Marsha Rosner at the University of Chicago, researchers exposed human lung cells to SARS-CoV-2 and CBD.
CBD did not prevent viral entry but strongly inhibited replication inside cells. Notably, it worked against three SARS-CoV-2 variants.
In mice, a week-long CBD treatment reduced infection in lungs and nasal passages.
Supporting evidence came from the National COVID Cohort Collaborative database: Among 1,212 epilepsy patients prescribed CBD, COVID-19 positivity rates were significantly lower than in matched controls.
These findings do not mean CBD prevents COVID-19. Researchers stress they are preliminary; CBD is no substitute for vaccines or public health measures. Many commercial CBD products lack sufficient purity or dosage for these effects—the study used high-purity compounds.
As Dr. Rosner notes, "Going to the local bakery and buying muffins probably won't do anything." Yet, "the results are promising. We are eager to see clinical trials begin." Human trials are now planned.
