Smoking Weed Does Not Protect You From Covid-19

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Scientific papers don’t usually go viral, but this week, a team of researchers from Oregon State University published a study that contained the magic formula to blow up the internet: cannabis and Covid-19.

According to research published Monday in the Journal of Natural Products (and subsequently rewritten in almost every news outlet on Earth) two compounds found in hemp plants—specifically, acids that become active cannabinoids only after heat is applied—“prevented entry” of the novel coronavirus that causes Covid-19 into isolated human cells.

This could mean that certain cannabis-derived preparations, given in the right amount, might help people fight off Covid-19. Which is exciting stuff!

What this research does not mean is that smoking cannabis helps protect you from the coronavirus, or that “weed stops Covid” (at least in the practical sense), or that the reason why someone got sick with Covid while someone else didn’t had anything to do with cannabis.

Yet by the time the story began appearing in every news outlet, aggregator, Facebook post, and clout-chasing social media account by Wednesday morning, that was the meaning the research had taken on.

The intent here isn’t to pick on individuals for misunderstanding or being misled. They’re just there as a representative sample of similar discourse appeared everywhere the study appeared. Weed kills Covid-19, cannabis will end the pandemic!

Of course, the study authors made no such claims, and anyone who read the research—or, in the media’s defense, any of the coverage past the headlines—would have known that. The problem is twofold: very few people do that, and even those that do have a poor understanding of the difference between a cannabinoid and a cannabinoid acid.

In an interview with VICE, Richard van Breemen, a professor of medicinal chemistry at Oregon State and the study’s lead author, explained that the researchers wanted to investigate what natural products might help humans fight off the virus.

They discovered that three compounds in hemp “had this high ability to bind to the spike protein” that allow the novel coronavirus to enter human cells so easily and thus spread Covid-19 so quickly.

The three compounds are cannabidiolic acid (CBD-A), cannabigerolic acid (CBG-A), and tetrahydrocannabinolic acid (THC-A). In cannabis biochemistry, acids are the biosynthetic precursors to the cannabinoids that activate receptors in humans, i.e. “get you high.” This means, in simple terms, the cannabis compounds studied in this research are not the cannabis compounds most weed users seek when they go to the dispensary.

And they are not the compounds you ingest when eating an edible or smoking a joint, because these acids are transformed when heat is applied—from THC-A to THC, from CBD-A to CBD, from CBG-A to CBD. And neither CBD, THC, nor CBG are “active against the virus,” van Breemen said.

As van Breemen told VICE, a “dietary supplement” such as a gummy or a tincture that contains all three of these compounds might help people stay healthy. (Crucially, the researchers could not study THC-A due to federal drug laws.)

But since most commercially available cannabis, whether sold in licensed stores or on the traditional market, has very little CBD or CBG, most commercially available cannabis won’t do a thing for your Covid-19 situation—and no cannabis will do anything if you smoke it.

And we don’t yet know if even these compounds will actually do anything either.

“What happens in a test tube does not always translate into what happens in animals or humans,” observed Dr. Patricia Frye, a physician and cannabis expert who practices integrative medicine and teaches at the University of Maryland School of Pharmacy. But “as it stands, we do not know if cannabidiolic acid or cannabigerolic acid will prevent infection.”

“And given that there are now treatments for Covid infections in at-risk patients (monoclonal antibodies, anti-virals), I would not recommend using cannabis in lieu of available treatments if a person is at high risk of poor outcome,” she added.

Frye noted that both the study’s authors as well as most coverage was perfectly clear. But not everyone—and not everyone who smokes cannabis, even!—knows the difference between THC and THC-A.

For that reason, “I am sure that many in the public who don’t understand what the acids are might think that smoking cannabis could prevent Covid,” she said.

“We have no reason to think that smoking weed protects you,” agreed Dr. Peter Grinspoon, a physician at Massachusetts General Hospital and instructor at Harvard Medical School who regularly writes about cannabis. “Smoking anything isn’t a good idea during a pandemic that affects the lungs; better to vape ground flower or use a tincture.”

And Grinspoon threw even more cold water on the excitement. “These compounds would need to be tested in animals, then in humans, and actually demonstrated to be effective against Covid. This is a long way off, assuming they work, which is by no means guaranteed,” he said. “I don’t think many molecules at that level actually pan out into functional medicines.”