The FDA is working to answer questions about the science, safety, and quality of products containing cannabis and cannabis-derived compounds, particularly CBD.
The FDA is committed to setting sound, science-based policy. The FDA is raising these safety, marketing, and labeling concerns because we want you to know what we know. We encourage consumers to think carefully before exposing themselves, their family, or their pets, to any product, especially products like CBD, which may have potential risks, be of unknown quality, and have unproven benefits.
Potential harm, side effects and unknowns
The FDA is concerned that people may mistakenly believe that using CBD “can’t hurt.” The agency wants to be clear that we have seen only limited data about CBD’s safety and these data point to real risks that need to be considered. As part of the drug review and approval process for the prescription drug containing CBD, it was determined that the risks are outweighed by the benefits of the approved drug for the particular population for which it was intended. Consumer use of any CBD products should always be discussed with a healthcare provider. Consumers should be aware of the potential risks associated with using CBD products. Some of these can occur without your awareness, such as:
Misleading, unproven, or false claims associated with CBD products may lead consumers to put off getting important medical care, such as proper diagnosis, treatment, and supportive care. For that reason, it’s important to talk to your doctor about the best way to treat diseases or conditions with available FDA-approved treatment options.
In addition to safety risks and unproven claims, the quality of many CBD products may also be in question. The FDA is also concerned that a lack of appropriate processing controls and practices can put consumers at additional risks. For example, the agency has tested the chemical content of cannabinoid compounds in some of the products, and many were found to not contain the levels of CBD they claimed. We are also investigating reports of CBD potentially containing unsafe levels of contaminants (e.g., pesticides, heavy metals, THC).
CBD oil may also increase liver enzymes (a marker of liver inflammation). People with liver disease should use CBD oil with caution, ideally under the care of a doctor who can regularly check blood liver enzyme levels.
Part of this response could be explained by the way that CBD acts in the brain. In low doses, CBD may act as an agonist to several receptor sites, meaning it acts similarly to surrounding molecules that normally bind to the receptor, enhancing the signalling of those receptor sites. At higher doses, however, too much activity at the receptor site can lead to an opposite effect, negating the beneficial effects of CBD.
CBD oil contains CBD mixed with an inert carrier oil, such as coconut oil or hemp seed oil. The bottled oil, called a tincture, is sold in various concentrations. There are also CBD capsules, CBD gummies, and under-the-tongue CBD sprays.
Possible Side Effects
CBD is the short name for cannabidiol, one of the two chemicals—among the dozens in cannabis—that have the most health benefits. The other, tetrahydrocannabinol (THC), produces the psychoactive effects described as being “high.” CBD oil generally does not contain THC, although some trace amounts may be present in products sold in certain states.
CBD oil may benefit those with drug addiction, suggests a 2015 review of studies published in Substance Abuse.
Meredith Bull, ND, is a licensed naturopathic doctor with a private practice in Los Angeles, California.
Outside of these two disorders, CBD’s effectiveness in treating seizures is uncertain. Even with Epidiolex, it is uncertain whether the anti-seizure effects can be attributed to CBD or some other factor.
Also known as “cotton mouth,” CBD can potentially cause your mouth and eyes to feel very dry, notes Dr. Brent A. Bauer via Mayo Clinic. Though this side effect is more likely to occur with THC, it can happen with CBD, as well.
“CBD is not an intoxicating substance, whereas THC is a psychoactive that can get you high,” explains Dr. Jas Matharu-Daley, a physician and consultant for a brand that specializes in CBD production.
“If the CBD is from a reputable source and one that has been inspected by a third-party independent lab, the content of CBD is more reliable,” notes Dr. Matharu-Daley. “The CBD should be organically grown, free of pesticides and heavy metals, and not sourced in food which can affect absorption. Generally, CBD is safe and side effects are few at low doses.”
She adds, “[Another difference is that] CBD is derived from hemp and has been classified as a legal substance. Hemp has <0.3% THC. Conversely, cannabis plants such as marijuana are grown to have much higher levels of THC and are still illegal according to the FDA, although individual states vary as to their use.”
Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.