Depending on who’s talking about CBD—short for cannabadiol, the nonpsychoactive compound found in marijuana and hemp plants—it’s either a cure-all for every ailment, or little better than a placebo. Since 33 states (and the District of Columbia) have legalized medical marijuana, and the 2018 Farm Bill legalized hemp, physicians may be seeing more requests from patients to try these products. What do physicians need to know to best inform their patients? The answers lie somewhere in the middle of the two extremes.
What is CBD?
CBD is one of hundreds of cannabinoids found in the cannabis sativa plant (marijuana and hemp) that does not cause the euphoria or intoxication of its cousin compound, THC.
“CBD binds to different receptors than THC,” says Jack Springer, MD, Fellow at the American College of Emergency Medicine and assistant professor of Emergency Medicine at the Zucker School of Medicine at Hofstra Northwell in San Diego, Calif.
Researchers are only just beginning to understand the endocannabanoid system in the human body, he says, which were only discovered around the 1990s. “Since that time this system has been found to have numerous important functions on the body relating to appetite and energy balance, immune function and nervous system function,” Springer says.
CBD, a phytocannabanoid—deriving from plants—is frequently touted as relieving such conditions as chronic pain and inflammation, anxiety, and sleep issues, says Rosemary Mazanet, MD, PhD, an oncologist and Chief Scientist at Columbia Care, a provider of medical cannabis products in 13 states.
However, when it comes to the evidence, most claims are only anecdotal. Research studies in the U.S. on CBD are still limited.
Mazanet says that many of CBD’s positive effects on these conditions may be placebo, but she does not consider that a bad thing, particularly for issues such as anxiety. “Even if it’s placebo, if people think it’s working for them, that’s good because people take so many benzodiazepenes, which can be addictive over periods of time,” Mazanet says.
Other physicians believe that taking CBD alone is missing the effectiveness of the whole cannabis (marijuana) plant, which includes THC and numerous other cannabanoids, which work together in what is known as an “entourage effect.”
Jordan Tishler, MD, an internist and professor at Harvard Medical School in Brookline, Massachusetts, and president of the Association of Cannabis Specialists, also believes that the benefits the average person is getting from CBD are likely placebo, and that it’s THC that can really treat symptoms. “If you think about the general things cannabis is used for—pain control, nausea suppression, appetite stimulation, treatment of anxiety—that’s all THC… in proper dosing and in proper timing that’s actually working.”
However, any of the compounds of cannabis in isolation have their downsides, even THC, Tishler says. This is evidenced by the failure of a drug called Marinol, released in the 1980s, which was essentially pure THC. “It didn’t work well because most people got so intoxicated that they never achieved the therapeutic value,” Tishler says.
Because both hemp and marijuana were considered illicit substances for so long, research on CBD in the United States has been limited. Thus, there simply isn’t enough convincing scientific evidence yet to back up any specific usage of CBD with one exception. The only FDA approved use for CBD in the U.S., Tishler says, is the FDA approved drug Epidiolex, used to treat seizures associated with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) in patients 2 years of age and older. Even then, it does not work for every patient who takes it.
Tishler says that the dosage of CBD required to bring benefit to the average person is so high—between 600 and 1200 mg of CBD per day—it is also cost prohibitive for many. He estimates CBD costs approximately five cents per milligram, which would make a therapeutic dose of CBD about $80 per person per day. “You need so much CBD to make a dent,” Tishler says.
In an attempt to provide some concrete evidence on effectiveness of CBD and THC, The National Academy of Science Engineering and Medicine released a report in 2017 that found the following:
“Conclusive or substantial evidence” that cannabanoids (not specifically CBD) are effective as antiemetics in the treatment of chemotherapy-induced nausea and vomiting (with oral cannabinoids); and improving patient-reported multiple sclerosis spasticity symptoms (with oral cannabinoids).
“Moderate evidence” that cannabanoids improve short-term sleep outcomes in individuals with sleep disturbance associated with obstructive sleep apnea syndrome, fibromyalgia, chronic pain, and multiple sclerosis (primarily nabiximols).
For everything else, evidence is “limited or inconclusive.”
“The important thing to get across is that nothing is a panacea,” says Springer. “Until we dial in the mechanism of action and can pick apart which cannabinoid is most beneficial for what and can isolate it, we’re not going to know.”
He urges physicians to be cautious about making claims that CBD is definitely going to work for any specific ailment or disease.
While there aren’t a lot of known side effects to CBD other than diarrhea, upset stomach and occasional lightheadedness, Springer says, he feels the marketing of CBD downplays any potential side effects. “Anything you put in your body is going to have an effect. The issue comes down to what form and dose are you taking,” Springer says.
Side effects are also much more likely at higher dosages, which is where Tishler urges caution. “Having CBD at placebo levels is probably not a big deal, but high levels of CBD are probably something we want with some control, or people will get drug interactions.”
The legal question
In addition to questions about CBD’s curative claims, there’s some gray area around its legality. There’s an erroneous assumption that marijuana is illegal and hemp is legal, therefore, CBD derived from hemp is assumed to be legal as well. William Garvin, JD, shareholder for the law firm Buchanan, Ingersall, and Rooney in Washington D.C., and co-head of its cannabis group, which handles issues related to the regulation and sale of cannabis, says, “The problem is that marijuana and hemp have the same genus species of plant.”
Thus, he says, hemp has long been lumped in with marijuana, legally speaking, and treated as illegal even though hemp does not contain enough THC to create intoxication. That muddied the legal waters in states where local authorities don’t know the difference between the plants, and has kept even hemp-derived CBD from being legal to buy and sell in every state.
The passage of the 2018 Farm Bill has legalized hemp, and thus hemp-derived CBD, so long as the producer is licensed and in compliance with federal or state agricultural standards.
However, no such federal agricultural program exists yet, Tishler says.
The legalization of hemp may change who is allowed to produce and sell CBD, by requiring more stringent standards, but Garvin thinks that might be a benefit to the consumer by creating more consistent and standardized products.
All of that said, there is often lag time between legislation and law enforcement, so Garvin urges CBD users, “Don’t take [CBD] through airports. Treat it as a product that could have difficult with authorities because you never know which authorities are going to be on board with it and which ones aren’t.”
Mazanet also cautions that not all CBD products are created equally, or with any consistent manufacturing standards. “When patients buy CBD products over the counter or from the gas station, they have no idea what they’re getting,” she says.
She points to a 2017 study in JAMA where researchers tested 84 CBD products they purchased over the internet from 31 different companies—40 oil products, 20 tinctures, and 20 vaporizations. “Less than half of the products had in them what they said they had in them,” Mazanet says. “There’s really no oversight in what people buy.”
Springer says even dispensaries in states with medical marijuana are not always the most reliable source.
That being said, Mazanet accepts that patients who want CBD products are going to get them, and feels that physicians should try to work with these patients. “The thing that’s most important is that physicians don’t send their patients elsewhere,” she says.
Springer urges physicians to encourage their patients to do their research before purchasing products and to acquaint themselves with quality brands for those patients who are determined to buy them.
Like Mazanet, in the service of keeping rapport with his patients, Springer doesn’t write CBD off entirely because his patients are interested in it. He’s hopeful about research that shows cannabanoids may help to reduce dependence on other drugs, particularly opioids and benzodiazepenes, which can become addictive.
“For people who are opiate dependent or on a medication that has side effects, it’s a no brainer. If they’re willing, they should try to see if it helps,” Springer says.
Tishler is less likely to recommend CBD to his patients, however, (though he does recommend medical marijuana). “I don’t destroy patients’ response to placebo, but I don’t recommend placebo, either,” he says.
He feels it’s more important for doctors to figure out what the patient is trying to treat and focus on whether they need to intervene in some directed fashion. “If someone asks my opinion about [CBD] I’ll tell them it’s not particularly useful,” Tishler says.