Smoking marijuana will not protect you from the novel coronavirus, no matter what anyone says and no matter how much certain people want it to be true.
However, if taken in the right way and at the right amount, the cannabis compound CBD might lessen the severity of COVID-19 infection and even prevent the virus’s spread, new research published this week found.
What’s more, new anecdotal evidence suggests that people—not lab mice, and not isolated human cells, but human beings—who were prescribed regular high-potency doses of pharmaceutical-grade CBD were less likely to contract COVID, according to research published Thursday in the journal Science Advances.
“Our research suggest that CBD and its metabolite 7-OH-CBD,” which is a compound produced after the body processes CBD, “can block SARS-Cov-2 infection at early and even later stages of infection,” wrote the researchers, led by academics at the University of Chicago.
Thursday’s findings come on the heels of research published last week that found cannibidiolic acid—or CBD-A, the precursor molecule to CBD, as well as other similar cannabis acids that become the familiar cannabinoids when heated—prevented the entry of the coronavirus into isolated human cells.
Taken together, these findings are fueling a misconception that smoking cannabis or taking over-the-counter CBD drops are a useful tool against COVID. They’re not.
What the findings may mean that cannabis-derived medicines or preparations might supplement vaccines in the struggle to end the nearly two-year-long COVID-19 pandemic.
But—and researchers cannot stress this enough—what it does not mean is that smoking a joint treats COVID. And your over-the-counter CBD drops won’t, either.
In interviews, researchers highlighted both the potential significance of their work as well as its limitations.
“As a bottom line, what this says is that CBD has the potential to prevent infections, such as breakthrough infections, which might be one of the most useful applications,” as Marsha Rosner, a professor of cancer research at the University of Chicago and a lead study author, said in an interview with VICE’s Motherboard vertical.
However, as the researchers wrote, the findings were limited to just CBD—and just to certain high-grade CBD preparations that deliver a very large dose of the compound.
"Going to your corner bakery and buying some CBD muffins or gummy bears probably won't do anything," Rosner said in a news release.
And nothing in the study indicates CBD is a replacement for existing preventative measures, such as masking and vaccinations—both of which the researchers hope people continue to do.
“What we don't want,” she added, “is people just running out and thinking, ‘I can take CBD, and then I don't have to get vaccinated or I don't have to be masked.”
“This is what we really don't want to see.”
Rosner and her colleagues treated human lung cells with CBD prior to infecting them with the SARS-CoV-2 virus. And they found that “CBD potently inhibited viral replication under non-toxic conditions,” they wrote, adding that other cannabinoids, including “psychoactive THC,” did not do this.
“Remarkably,” they wrote, “only CBD was a potent agent.”
How did CBD do this? The cannabinoid appears to activate a cellular stress response normally triggered in the presence of “viruses or other pathogens,” as Rosner said in a phone interview on Friday. This stress response produces a series of proteins called interferons. And
“CBD induces the production of interferons, and they are the antivirals that will fight the virus,” Rosner said.
CBD also prevented the virus from making other changes to infected host cells.
But cells are cells—they’re not living beings. To test the findings on living beings—something last week’s study did not do—female mice were given two loads of CBD: 20 or 80 mg per kilogram of body weight.
That’s a fairly substantial dose that could be exorbitantly expensive: A 150-pound person would have to take a heroic 5,440 milligrams of CBD to match the mice—and some companies sell 10,000 milligrams, or less than two doses, for $250.
Nevertheless, some will argue that’s money and CBD well spent.
According to the researchers, mice that took 80 milligrams of CBD per kilo of weight saw decreases of viral loads in the lungs and the nose up to “40- and 4.8-fold.”
And, finally, there is some evidence that these mice and test-tube studies will translate to people.
Epidiolex is a CBD-based pharmaceutical drug approved for prescription by the federal Food and Drug Administration for patients with severe seizure disorder.
A review of 1,212 patients in a dataset called the National COVID Cohort Collaborative revealed showed that the COVID infection rate among people with a “medication record” of taking pharmaceutical-grade CBD was 6.2 percent, compared to 8.9 percent for people not taking CBD, the researchers wrote.
But CBD’s preventative potential was even more pronounced for people who took CBD the same day as their COVID-19 tests. For a subset of 531 patients “who were likely taking” 100 milligrams of CBD, their positivity rate was 4.9 percent, compared to rate of 9 percent among a control group not taking the drug.
Going forward, Rosner and her colleagues are hoping that clinical trials with humans can begin—and begin soon, as the pandemic grinds on through historic-high levels of infections and hospitalizations, a dreadful winter spike fueled by the omicron variant.
“We are very eager to see some clinical trials on this subject get off the ground," Rosner told the University of Chicago’s news service.
“Especially as we are seeing that the pandemic is still nowhere near the end,” she added, “determining whether this generally safe, well-tolerated, and non-psychoactive cannabinoid might have anti-viral effects against COVID-19 is of critical importance.”