Pop open a seltzer or eat a cookie and feel extra relaxed—that’s the promise of CBD (aka “cannabidiol”)–infused drinks. Major food and beverage companies such as Mondelez, Molson, and Alkaline88 have expressed interest in marketing CBD-infused food and drinks. While you might be able to find CBD beverages sold in some stores (it depends on where you live), you can’t walk into any supermarket in America and grab a pack of CBD cookies.
CBD is a chemical compound extracted from the cannabis plant. It doesn’t get you high; it just might (might!) make you feel calm. As long it’s extracted from hemp, it’s technically legal under the federal law—unless it’s sold in a food or as a drink.
The Food and Drug Administration has been expressing disapproval for almost all CBD products except an oral prescription drug called Epidiolex that is used to treat seizures in children, which the FDA says is a “highly purified form of CBD.” The FDA has several concerns about CBD going into other drugs, and food and drinks. One of the main side effects the agency is concerned about is potential liver damage.
But is CBD really that harmful to the liver? After all, people already use CBD products all the time. Despite the FDA’s reservations, some states have even legalized CBD food and beverages.
“As far as I know, there have not been an influx of cases of healthy adults taking retail products and having acute liver toxicity,” says Ryan Vandrey, a professor of psychiatry at Johns Hopkins who researches the behavioral effect of cannabis. By and large, CBD as a chemical entity is relatively safe, Vandrey says. But there are some important caveats, including when it comes to liver function.
Here’s where that particular concern comes from: While using the FDA-approved Epidiolex, some children developed problems with their liver. Specifically, their enzyme levels went up, which is a sign that the organ is either inflamed or damaged, explains Robert Kaufmann, an Illinois-based physician who has consulted for cannabis companies like American Shaman.
But a 2020 study that analyzed 12 previous clinical trials comprising 800 participants notes that liver issues occur in kids taking both Epidiolex and another anti-epilepsy drug, one that is known to cause liver enzyme elevations. “CBD can cause some liver function elevations,” explains Kaufmann, “But it’s almost always associated with the taking of other drugs.”
Studies with animals do clearly show that extremely high doses of CBD are damaging to the liver. In one study, researchers administered CBD extract to mice. The animals died after four days (again, the doses they gave the mice were extremely high). When they slightly lowered the dose so that the mice lived, they observed elevated liver enzymes. Although the study doesn’t reflect a real-life scenario, it pinpointed the adverse effects that CBD could cause when we take it in really high doses.
There’s some research evidence that CBD is just fine for human livers in small doses: One study that Kaufmann published last year in Cannabis and Cannabinoid Research involved around 800 people taking CBD, and it concludes that self-medication of CBD doesn’t damage the liver. (For Kaufmann’s study, 12 CBD product companies provided funding.) Around 30 days after participants consumed CBD, researchers performed liver tests on the study participants and found that everything looked normal. Studies examining the effect of high doses of CBD have not been done in humans yet, but Kaufmann and Eric Leas, an assistant professor at the University of California, San Diego, who specializes in drug policy, both told me that heightened levels of CBD could indeed be detrimental to us. “Moderation,” emphasized Kaufmann. CBD could be an issue “if you put too much load on your liver.”
That’s where the problem with food and drink loaded with CBD comes in—moderation can be trickier if you aren’t taking a precise dose. “If you don’t have CBD in the form of a pill, and [you’re] adding it to coffee or salad, you never know how much CBD you are consuming,” says Leas. Imagine having several CBD beers over the course of a night, and not really keeping track—and then doing that regularly, along with having CBD snacks in between. It’s possible that that could all add up to concerning levels of CBD.
What about CBD-instilled tinctures and oils that are applied to the skin, and which are easily available to buy right now? Though it could be easy to slather on more oil than is intended, such topical products get absorbed in very little quantities in the bloodstream, says Vandrey.
In CBD products, there can also be other chemical compounds that cause harm, says Vandrey. If you purchase CBD, you should buy it from a reputable source that shares certificates of analysis to confirm that the product isn’t contaminated.
Interestingly, in small doses, CBD could in fact have some beneficial effects on the liver, Kaufmann says. In lab animal models, it’s been shown that CBD can reduce the onset of Type 2 diabetes, which is associated with liver disease. What’s more, studies in mice models even say that low doses of CBD could be beneficial by reducing inflammation in liver. Kaufmann cautions that we really cannot be sure if these benefits will also show up in humans—in most animal studies, researchers inject the drug into animals, rather than giving it to them orally.
CBD’s effect on the liver should be researched more. Vandrey says we need to be mindful of the limitations of the data that we have and collect more information to better understand the cases in which CBD can impair liver function.
In the meantime, having a little bit of CBD to relax won’t hurt. After all, too much beer can cause liver issues, too.