Two new studies suggest that some cannabis compounds, including CBD, offer protection against the virus that causes COVID-19. The encouraging findings should lead to additional funding for research on the antiviral properties of cannabis.
A study published yesterday in the journal Science Advances by researchers from the University of Chicago and University of Louisville found that CBD prevents the SARS CoV-2 virus from effectively replicating in human cells.
The researchers also found that patients taking prescription CBD (the FDA-approved drug Epidiolex, prescribed for seizure disorders) were much less likely to become infected with COVID-19, the disease caused by the SARS CoV-2 coronavirus.
The researchers first hypothesized that CBD’s anti-inflammatory properties could help treat the “cytokine storm” stage of COVID-19, in which the body’s immune system overreacts to the presence of the virus and triggers dangerous levels of inflammation.
What they found was even more exciting: while CBD doesn’t keep the virus from entering lung cells, it does prevent the virus from replicating once there. Lab experiments on human lung cells and mice confirmed the effect. The researchers also duplicated the result achieved with the original SARS CoV-2 strain on three additional variants of the coronavirus.
“We just wanted to know if CBD would affect the immune system,” said senior author Dr. Marsha Rosner, a University of Chicago professor. “No one in their right mind would have ever thought that it blocked viral replication, but that’s what it did.”
The authors of the study say clinical trials should be planned to study whether CBD could be prescribed as a preventative for COVID-19 or a treatment for people in early stages of the disease.
The researchers used high concentrations of purified CBD (as is found in Epidiolex), and found that CBD mixed with other cannabinoids like THC were less effective. They cautioned that consumer CBD products may not offer the purity or precise dosing necessary to produce the effects their experiments achieved.
But while the researchers suggest that commercial CBD products may not offer the same anti-COVID benefits, the news could nevertheless revitalize the sagging CBD market. The non-intoxicating cannabinoid experienced explosive market growth following passage of the 2018 Farm Bill that legalized hemp cultivation, but faded in popularity as intoxicating THC variants like delta-8 THC and HHC became more widely available. CBD has a number of known health benefits—aside from treating COVID-19—and is generally safe and legal for consumer use in most places in the United States.
The University of Chicago study comes less than two weeks after Oregon State University and Oregon Health & Science University researchers published a study in the Journal of Natural Products showing that the acid forms of cannabinoids CBD and CBG block SARS CoV-2 from entering human cells.
Cannabidiolic acid (CBD-A) and cannabigerolic acid (CBG-A) are the precursor forms of those cannabinoids. They occur naturally in hemp and marijuana plants. When heated (decarboxylated), they become cannabidiol (CBD) and cannabigerol (CBG), and most of their known properties are unlocked.
The Oregon State researchers found that the acid forms of those compounds bind to the SARS-CoV-2 spike protein and interfere with the virus’s ability to infect human cells. “Orally bioavailable and with a long history of safe human use, these cannabinoids, isolated or in hemp extracts, have the potential to prevent as well as treat infection by SARS-CoV-2,” says the study.
“They bind to the spike proteins so those proteins can’t bind to the ACE2 enzyme, which is abundant on the outer membrane of endothelial cells in the lungs and other organs,” said study co-author Dr. Richard van Breemen, a researcher with Oregon State’s Global Hemp Innovation Center, College of Pharmacy, and Linus Pauling Institute.
“With widespread use of cannabinoids, resistant [coronavirus] variants could still arise, but the combination of vaccination and CBDA/CBGA treatment should create a more challenging environment with which SARS-CoV-2 must contend, reducing the likelihood of escape,” the authors write in the study.