CBD—short for cannabidiol—is a compound extracted from the marijuana plant that’s touted in ads as a way to relieve everything from chronic pain to anxiety to insomnia. Seemingly overnight, a dizzying array of products that contain CBD is now on sale in convenience stores and other retailers or online. They come in the form of ingestible tinctures (drops), oils, vaping liquids, lotions, sprays, capsules—even gummy bears. CBD is in beauty products, chocolate bars, popcorn, peanut butter, and dog treats. You can order a CBD-laced latte or get a CBD-infused massage.
Americans are clearly intrigued: The number of Google searches for “CBD” or “cannabidiol” has increased well over 100 percent annually since 2017 in the United States, according to a study led by University of California, San Diego, researchers and published online in October 2019 in JAMA Network Open. There were 6.4 million Google searches in April 2019 alone, which far exceeded the number of searches for other health topics like “diet,” “exercise,” and “meditation” during the same period.
Is it pot or not?
CBD is one of the more than 100 chemical compounds known as cannabinoids that come from marijuana or its close relative hemp (both are varieties of the plant Cannabis sativa). But unlike another well-known compound from the marijuana plant, tetrahydrocannabinol (THC), CBD doesn’t get users high. THC produces intoxicating effects when smoked or consumed, such as in brownies or other “edibles.” CBD doesn’t have the same effect as THC on the brain.
Hemp also contains a very small amount of THC and is grown for a number of uses, such as making paper and cloth. Hemp is also used as an ingredient in an increasing number of foods and beverages. Hemp is a rich source of CBD. By U.S. law, CBD products (sometimes labeled “CBD oil” or “hemp oil”) derived from hemp plants can contain no more than 0.3 percent THC by weight.
Fuzzy legal status
Federal and state laws are at odds with one another over CBD’s legal status. The federal 2018 Farm Bill gave U.S. farmers the OK to grow and sell hemp. Yet the FDA has approved the use of only one form of CBD, a prescription-only oral solution called Epidiolex, for prevention of epileptic seizures. Because the FDA deems CBD to be an investigational drug, the agency forbids its sale in dietary supplements and foods. (The FDA doesn’t regulate ingredients in beauty products, and so far using CBD in cosmetics isn’t restricted.)
To confuse matters further, states often override federal laws, and most allow the sale of products containing CBD oil derived from hemp, though in some states you may need to obtain a note from your doctor and purchase products at a special dispensary. Also, the types of CBD products you can buy depends on where you live. For example, Massachusetts forbids the sale of foods containing CBD, while neighboring New York permits CBD edibles. Three states—Idaho, Nebraska, and South Dakota—prohibit the sale of cannabis products, although CBD sometimes falls into a gray area of the law. It’s safe to say that state and federal regulators are still sorting out CBD’s legal status, so laws throughout the country will likely evolve.
What might CBD do for you?
In 2018, the FDA approved Epidiolex for reducing seizures in people with two rare but severe forms of epilepsy. All other alleged health benefits linked to CBD are unproven, despite claims on package labels. Animal studies indicate that CBD appears to have some medicinal properties, such as tamping down inflammation (at least in mice!). As yet, there’s no robust scientific evidence to support most health claims.
Here’s what we know about some of the more common reasons people use CBD:
- Chronic pain. A modest body of evidence suggests that cannabis contains substances that ease chronic pain. In fact, a cannabis-based pain reliever containing THC and CBD called Sativex is available in 27 countries including Canada and the United Kingdom (but not in the United States) for treatment of pain and muscle spasticity caused by multiple sclerosis. However, it’s hard to say whether CBD alone does the same. Overall, little research has been done on whether CBD, in isolation, provides pain relief. Researchers have studied its effectiveness in easing nerve pain, but the studies have been too small to be relevant, and results have been inconsistent.
- Anxiety and depression. The few studies of CBD for anxiety in humans were small and short term. In a Brazilian study published in 2011 in Neuropsychopharmacology, 24 adults with social anxiety disorder were given 600 mg of CBD, then asked to deliver a speech. Compared to untreated healthy control subjects asked to give speeches, the CBD users reported less anxiety and discomfort. However, another small study, published in 2017 in Cannabis and Cannabinoid Research, found that treating healthy subjects with varying doses of CBD failed to dampen their emotional responses to upsetting or threatening images and words. There’s even less support for the idea that CBD relieves depression.
- Sleep problems. A review in the August 2019 issue of Experimental and Clinical Psychopharmacology found some evidence that CBD may help you fall asleep faster, wake up less often while you’re in bed, and get a better night’s rest. However, most of the studies reviewed were small, so carefully designed studies are needed.
- Other conditions. Limited evidence suggests that CBD could help improve Parkinson’s disease symptoms and might help curb opioid addiction, but much more research is needed. Studies have failed to find benefit in other diseases, including Crohn’s disease (an inflammatory bowel disorder) and diabetes. Product claims that CBD can treat Alzheimer’s disease, cancer, and pet anxiety are all unsubstantiated.
Safety Tips for Buying CBD
The fast-growing market for CBD products is largely unregulated, and not all products may be safe. These steps can help you protect yourself.
Not to be taken lightly
Reviews of multiple small-scale, short-term human studies have found that pharmaceutical-grade CBD is generally safe, but the high-quality products used in most studies may differ from those in over-the-counter CBD products. The World Health Organization (WHO) stated in a 2018 report that “in humans, CBD exhibits no effects indicative of any abuse or dependence potential.… To date, there is no evidence of public health-related problems associated with the use of pure CBD.” However, the FDA says that evidence is insufficient to deem CBD safe when used as an ingredient in human and animal food.
Despite the WHO’s assessment, CBD is not risk-free. If you decide to try CBD, always talk with your doctor first and bear in mind the following potential concerns:
- Adverse effects: In clinical trials, some people treated with Epidiolex reported drowsiness, diarrhea, loss of appetite, and other side effects. Liver damage has occurred, too, and patients who take Epidiolex must have their liver function regularly monitored. Similar side effects and liver injury have been reported in studies of CBD use for other purposes. What’s more, nothing is known about CBD’s long-term adverse effects, especially in older adults with chronic conditions.
- Drug interactions: CBD may interfere with the effectiveness and metabolism of some common drugs. According to reports, CBD heightens the activity of the anticoagulant warfarin (Coumadin), which can increase bleeding risk. Using CBD with drugs that depress the central nervous system, such as benzodiazepines like alprazolam (Xanax) and diazepam (Valium), can induce or intensify drowsiness and sedation. CBT can amplify the potency and side effects of other drugs, such as the muscle relaxant chlorzoxazone (Lorzone) and the bronchodilator theophylline (Theo-Dur, Theochron, others), and interact with herbs and supplements, such as melatonin and St. John’s wort, as well as alcohol. Some antibiotics and antifungal medications can affect CBD’s potency.
- Quality problems: Since there’s minimal oversight of the CBD market, there’s no guarantee that the information on the product’s labels is accurate, and manufacturers have little incentive to closely monitor the quality of their merchandise. Some products have been found to be contaminated with microorganisms and pesticides and other chemicals. A 2017 analysis found that, of 84 CBD products purchased online, 26 percent contained substantially less CBD than stated on their labels, and 43 percent contained significantly more.
- Synthetic CBD: Beware of recreational products that add synthetic cannabis compounds to plant material, which could make you very sick. These products, which have names such as Spice or K2, have been found to contain contaminants such as rat poison and have been linked to severe bleeding and caused several deaths.
And there’s another risk to be aware of: If you use a CBD product (with the exception of Epidiolex), you might test positive for marijuana on a drug screening.
There isn’t enough evidence yet to recommend CBD for any medical use aside from the epileptic conditions it’s approved for. More research is needed to establish CBD’s safety, including safe and appropriate dosages, interaction with drugs and foods, and other potential side effects. Until then, it pays to approach CBD products with healthy skepticism.
This article first appeared in the UC Berkeley Wellness Letter.
Also see Edible Cannabis Riskier Than Inhaled.
Published March 17, 2020