To find out—because there’s been relatively little rigorous research on CBD to date and I’m a skeptic by nature—I reached out to a doctor and a scientist for the 411. As I suspected, this isn’t a topic that has been studied in depth. Yet there is some reason to believe that certain CBD products may truly be more bioavailable when absorbed under the tongue than if taken through food or drink.
Sublingual delivery isn’t always a better option for all substances, points out Dr. Birdsall—some B vitamins, for instance, need to be “activated” by the liver in order to do their jobs—but for certain vitamins and medications, it can be a super effective delivery method.
How does this apply to CBD? Surprise, surprise: It’s hard to say. “There has been very little scientific research on the sublingual absorption of CBD,” says Dr. Birdsall. The research that does exist has some inconsistencies, adds Kater, since there are so many factors that affect absorption—such as the quality of the CBD or the pH and consistency of the formulation. Plus, many of these studies focus on formulas that contain both CBD and THC—a psychoactive compound found in cannabis that’s supposed to be absent from CBD-only products—so it’s unclear whether their findings would also apply to a product that contains predominantly CBD.
If you are targeting specific symptoms of a condition, taking an oil, capsule, or gummy might be a better way to obtain a higher, more concentrated dose.
Starting at a lower dose and working your way up to the amount you need may be the best ways to avoid taking too much.
One of the most popular ways to take CBD is as an oil. Such products are made by combining CBD with some type of carrier oil, such as coconut oil. Some more recently developed products include dietary supplements, foods, beverages, lotions, salves, and cosmetics.
It may be helpful to take a broad-spectrum product since research suggests that CBD’s effects may be most beneficial when taken in conjunction with other cannabinoids, a phenomenon known as the entourage effect. CBD may also help mitigate some of the effects of THC.
What Kind Should You Take?
Federal law prohibits the sale of products that contain more than 0.3% THC. States laws also vary, so you should always check with your state before buying CBD products online.
It is important to remember that you should always talk to your doctor before using CBD if you have symptoms of a serious mental or physical health condition. CBD could potentially worsen symptoms or interact with other medications you are taking.
Looking at the dosage information for the CBD product that has been FDA approved can also be helpful. For Epidiolex, an FDA-approved cannabis-derived medication used to treat seizures in people with certain types of epilepsy, the starting dosage is 5 milligrams per kilogram of body weight. This dose can later be increased to 5 mg per kilogram of body weight twice a day.
How to Take CBD
John C. Umhau, MD, MPH, CPE is board-certified in addiction medicine and preventative medicine. He is the medical director at Alcohol Recovery Medicine. For over 20 years Dr. Umhau was a senior clinical investigator at the National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health (NIH).
Verywell / Madelyn Goodnight