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.
Even so, Kater says that “most of the literature supports the notion that CBD has better bioavailability when consumed sublingually versus orally. [and] MCT oil-based tinctures are thought to provide better uptake than a traditional oil.” But, again, there’s no evidence that this applies to the exact CBD oil or tincture that you, specifically, have in your cabinet. As mentioned before, every formulation is different, and those small differences matter when it comes to bioavailabilty.
Long story short: You may as well try holding your CBD oil or tincture under your tongue before swallowing it—you could find that you feel it working slightly faster. Anecdotally, says Dr. Birdsall, experts recommended that you hold it there for at least 60 seconds. (A word of warning: There will be drool.) Your other option is to try a product that’s specifically created to be absorbed sublingually, like Kin Slips, which are kind of like those breath-freshening films that dissolve in your mouth.
CBD oil may benefit those with drug addiction, suggests a 2015 review of studies published in Substance Abuse.
The tricky part is calculating the exact amount of CBD per milliliter of oil. Some tinctures have concentrations of 1,500 mg per 30 mL, while others have 3,000 mg per mL (or more).
There are no guidelines for the appropriate use of CBD oil. CBD oil is usually delivered sublingually (under the tongue). Most oils are sold in 30-milliliter (mL) bottles with a dropper cap.
In addition, the stroke volume (the amount of blood remaining in the heart after a heartbeat) was significantly reduced, meaning that the heart was pumping more efficiently.
Here are a few tips to help you find the best CBD oil: