CBD: what researchers and medical professionals do and don’t know


This post comes to us from departing science writing intern Tyler Fox, who graduated in May. Congrats, Tyler! And thanks for a year of great stories.

Cannabidiol, better known as CBD, is everywhere. Walgreens and CVS now offer lotions and snacks containing CBD. Local restaurants sell cocktails with CBD infusions. Brewers are adding it to their beers. The maker of Oreo and Chips Ahoy cookies is looking into incorporating it into their products.

As these products become more accessible, consumer interest continues to grow.

CBD is being credited with curing a wide range of ailments from chronic pain, post-traumatic stress disorder, insomnia, and even acne. But with all this excitement about this seemingly miraculous new health trend, how much do we really know about CBD’s effects?

“There’s a lot of claims made about CBD’s effects with low amounts of research to back them up,” says Dipesh Navsaria, a UW Health pediatrician at American Family Children’s Hospital. “What’s really important to remember about these products is that they’re entirely unregulated, which means these products don’t need proof that they do anything.”

These CBD products are now more readily available since the 2018 Farm Bill and state legislatures have allowed for wider agricultural production of hemp. Hemp is a strain of cannabis plant that contains a higher concentration of CBD but lower amounts of THC, an active ingredient in marijuana that causes its characteristic high.

CBD is a chemical compound naturally derived from the plant, which is perhaps more often associated with marijuana. But CBD is unique in how it acts on endocannabinoid receptors in humans to affect certain physiological processes. These receptors contribute to our appetite, pain sensation, mood and memory, which is why CBD products have a wide range of effects.

Only recently has the FDA specifically approved a medication containing CBD, which is used to treat rare epilepsy disorders. Beyond that, there is still too little evidence to confirm its touted effects. And with its connection to THC and marijuana production, the FDA has not yet classified CBD as a food or as a drug, so it isn’t regulated as such.

This means that supplement shops are making their own recommendations on what and how much consumers should use.

“Asking someone who sells CBD oils about how much to take can be a dangerous thing,” says Navsaria. “And we don’t have clinical trials on dosages, so it’s difficult to discuss with patients.”

Early research indicates that CBD is relatively safe, explains Natalie Schmitz, a UW–Madison School of Pharmacy researcher and former medical cannabis pharmacist at the University of Minnesota.

“It’s always better to start low and go slow with dosages, but right now the most common reported side effect with increased dosages is diarrhea,” says Schmitz.

However, without regulations, there is no guarantee that the labels of CBD products accurately represent the amount of CBD they claim. A 2017 article in the Journal of the American Medical Association found that of the 84 CBD products they tested, 26 percent contained less CBD than the label stated. And while most CBD products claim not to contain any THC, 21 percent of the products tested positive for the psychoactive THC compound.

This means that athletes who may be interested in using CBD in sports medicine applications should be very cautious in which products they choose.

With these concerns, Schmitz advises patients that are interested in trying CBD to do so cautiously and with frequent check-ins and communication with their healthcare providers.

Research confirms that long-term exposure to THC can affect memory and cognition, but these long-term studies haven’t yet been performed with CBD, which makes it more difficult for medical professionals to recommend its use.

While the FDA works to more closely regulate CBD products, it’s important to remember that there is no miracle drug. With wide and untested claims made about the compound, history reminds us that there is no cure-all. With every medication there are limitations and for CBD, we just don’t know them yet.

“Prescription medications cost what they do because we know what they’ll do,” says Navsaria. “I hope people wait to see how the research clarifies what CBD actually does.”