The CBD industry is flourishing, conservatively projected to hit $16 billion in the United States by 2025. Already, the plant extract is being added to cheeseburgers, toothpicks and breath sprays. More than 60 percent of CBD users have taken it for anxiety, according to a survey of 5,000 people, conducted by the Brightfield Group, a cannabis market research firm. Chronic pain, insomnia and depression follow behind. Kim Kardashian West, for example, turned to the product when “freaking out” over the birth of her fourth baby. The professional golfer Bubba Watson drifts off to sleep with it. And Martha Stewart’s French bulldog partakes, too.
A few drops of CBD oil in a mocha or smoothie are not likely to do anything, researchers contend. Doctors say another force may also be at play in people feeling good: the placebo effect. That’s when someone believes a drug is working and symptoms seem to improve.
What is CBD?
Last year, the F.D.A. approved Epidiolex, a purified CBD extract, to treat rare seizure disorders in patients 2 years or older after three randomized, double-blind and placebo-controlled clinical trials with 516 patients that showed the drug, taken along with other medications, helped to reduce seizures. These types of studies are the gold standard in medicine, in which participants are divided by chance, and neither the subject nor the investigator knows which group is taking the placebo or the medication.
However, a double-blind study found healthy volunteers administered CBD had little to no change in their emotional reaction to unpleasant images or words, compared to the placebo group. “If it’s a calming drug, it should change their responses to the stimuli,” said Harriet de Wit, co-author of the study and a professor in the University of Chicago’s department of psychiatry and behavioral neuroscience. “But it didn’t.”
“It’s promising in a lot of different therapeutic avenues because it’s relatively safe,” said James MacKillop, co-director of McMaster University’s Michael G. DeGroote Center for Medicinal Cannabis Research in Hamilton, Ontario.
Everyone wants a piece of CBD, and nobody is watching. Remember: There’s no regulation by the FDA or anyone else. An investigation by Natural Products Insider, a trade publication for the supplement industry, revealed that CBD producers are, at best, claiming to follow “good manufacturing practices” without any official oversight. It’s illegal to sell something that isn’t what its packaging claims it is — that falls under the purview of the Federal Trade Commission — but nobody is doing onsite testing.
For ingested CBD, that fat solubility is a problem. “[Ingested] CBD has a very low bioavailability, something between 6 and 15 percent, which varies between people,” says Blessing. Because ingested CBD is so inefficient at actually getting to the brain to stimulate CB1 and other receptors, the doses shown to be effective have to be very high. “There’s no evidence that doses below 300 mg of CBD have any effect in any psychiatric measure,” says Blessing. “And in fact, dose-finding studies show that the lowest clinically effective dose of CBD for reducing anxiety is 300 mg.” Blessing is talking about induced anxiety in otherwise healthy patients, which is all we have studies on; studies of CBD’s efficacy in treating clinical anxiety, which would require regular doses, haven’t been published.
It may have something to do with the fact that THC stimulates that CB1 receptor a lot, in turn triggering the psychoactive effects of marijuana like disturbed sensory perception, impaired motor skills, and anxiety. Conversely, CBD stimulates CB1 very lightly, causing some effects that seem downright opposed to those of THC including relief from anxiety, stress, and hyper-excitability.
What’s even in your favorite CBD product?
The exact legality of CBD is tricky. The Drug Enforcement Administration maintains that CBD is federally illegal but will not bother going after anyone for possessing or using it. Many argue that a provision in the 2014 farm bill allowing industrial hemp pilot programs, mostly aimed at the textile industry, actually made non-THC use of cannabis legal; while the much-delayed 2018 farm bill signed into law at the end of the year made industrial hemp legal nationwide, CBD has largely yet to be reclassified.
Esther Blessing is a professor and researcher at NYU who performs and reviews clinical trials on CBD’s effectiveness in treating post-traumatic stress, anxiety, substance addiction, and other conditions. Speaking about widely available and unregulated CBD oils, she says, “This is the main scam, snake oil thing going on out there now.”
Is it possible that all of this is just … the placebo effect? It feels condescending to suggest that, given there are hoards of people who love their CBD tinctures and gummies and claim effects from it. It’s a tremendously rude thing to say, hey, you’re all being hoodwinked. But the placebo effect is much stronger than you might think.
“CBD inhibits the cytochrome P450 enzymes that break down important psychiatric drugs,” says Blessing. CBD isn’t the only substance that messes with the body’s ability to metabolize these drugs — both St. John’s wort and the humble grapefruit are unfriendly — but CBD is comparatively poorly studied. The way CBD inhibits those enzymes could dramatically raise the levels of SSRIs or opioids in the system, potentially leading to an overdose.