Cannabidiol, or CBD, a nonintoxicating component of the marijuana plant, is touted as a magic bullet that eases pain, anxiety, insomnia and depression. Salves, sprays, tinctures and oils containing CBD are marketed as aphrodisiacs that boost desire; as balms for eczema, pimples and hot flashes; and even as treatments for serious diseases like diabetes and multiple sclerosis.
Unlike THC or tetrahydrocannabinol, the “psychoactive” component of the cannabis plant, CBD won’t get you “high.” But scientists know little about what it can do: Most of the information about CBD’s effects in humans is anecdotal or extrapolated from animal studies, and few rigorous trials have been conducted.
“It is a kind of new snake oil in the sense that there are a lot of claims and not so much evidence,” said Dustin Lee, an assistant professor in psychiatry and behavioral sciences at Johns Hopkins University who is planning a human trial of CBD for use in quitting smoking.
The Food and Drug Administration has approved some drugs made from synthetic substances similar to THC to treat poor appetite and nausea in people with A.I.D.S. or cancer. But so far, the F.D.A. has approved only one drug containing CBD, Epidiolex, after clinical trials found it reduced seizures in children with two rare, severe forms of epilepsy.
“There’s a lot of hype about everything about CBD,” said Dr. Orrin Devinsky, the director of the NYU Langone Comprehensive Epilepsy Center, who led the Epidiolex studies and went out of his way to say the drug’s effect was “not miraculous.” “There is certainly data that it has a variety of anti-inflammatory effects, but whether that translates into improving human health is unknown. Does it help people with eczema, rheumatoid arthritis or ulcerative colitis? We don’t know. There is a good theoretical basis, but the studies have not been done.”
The F.D.A. still considers CBD a drug, so it cannot be sold in foods or drinks or as a dietary supplement, and several states and cities — including New York City, California, Maine and Ohio — have ordered restaurants to remove CBD from lattes, smoothies, muffins and other foods. The F.D.A. has issued several warnings to companies that make unproven claims that their CBD products will treat or prevent disease.
“This deceptive marketing of unproven treatments raises significant public health concerns, as it may keep some patients from accessing appropriate, recognized therapies to treat serious and even fatal diseases,” an F.D.A. spokesman said.
Dr. Yasmin Hurd, director of the Addiction Institute at Mount Sinai in New York City and a professor at the Icahn School of Medicine who has done extensive research on CBD, says the compound holds particular potential for the opioid crisis because it appears to reduce heroin cravings in recovering addicts. But, she said, “let’s do the research. It’s crazy that this substance is being consumed by everybody, yet we still don’t know the mechanism of action.”
CBD has a relatively good safety profile and is “hands-down safer generally than THC,” the intoxicating component of cannabis, Dr. Hurd said. But it can cause adverse side effects, including sleepiness and diarrhea. Patients in the Epidiolex trials also had more infections and rashes, as well as depressed appetite, sleep problems and elevated liver enzymes.