(This article originally appeared in AskCBD! and is republished here with permission.)
There are various forms by which one can ingest CBD, including tinctures, vaping oils, and edibles. The delivery method of CBD—what product type you choose to take your CBD—determines its bioavailability. Bioavailability is the percentage of the substance absorbed into the bloodstream after it is fully processed throughout the body. Knowing the bioavailability of your product allows you to tailor the product to your health and wellness goals.
Bioavailability is typically measured against intravenous administration, which results in 100 percent of the CBD being actively available. Though various studies may disagree about the different levels of bioavailability of CBD depending on the method of ingestion, for the most part, bioavailabilities of various product types fall into a standard range.
The following overview answers the question, “What is the bioavailability of CBD?”:
There are a few common factors that will affect the bioavailability of CBD regardless of the method of ingestion. According to madebyhemp.com, “All methods are affected by the hydrophobic properties of CBD oil.” In other words, CBD does not dissolve in water; rather it collects in fatty tissue, reducing the amount that goes into the bloodstream. For CBD edibles and capsules, this automatically lowers the bioavailability of CBD.
In addition to bioavailability, other factors such as body weight and product quality can greatly affect the active dosage of CBD. Consumers should always research the products before purchasing. When it comes to dosing, a person should always start with the lowest amount and work their way up until they find the correct dose that works for them.
Using CBD vape oil with a vaporizer or vape pen is one of the quickest ways to have CBD enter the bloodstream. Vaping is fast becoming one of the most popular ways to consume CBD. As madebyhemp.com explains, “When inhaled, the CBD enters the lungs and passes through tiny air sacs called alveoli, which exchange carbon dioxide and oxygen between the bloodstream and the lungs. CBD moves through the thin walls of the alveoli and directly into the bloodstream.” Bioavailability of vaping may be as high, or higher, than 50 percent.
Sublingual (oral) use of CBD refers to placing the oil under your tongue. This way the oil is absorbed through the mucous membranes. According to madebyhemp.com, “Capillaries in the connective tissue diffuse the substance, which then enters the bloodstream. In this method, the substance bypasses the first-pass metabolism.” While no percentages are available, sublingual usage has a very high percentage of bioavailability.
While many people love CBD edibles, be it gummies or cake pops or one of the myriad products available on the market today, it, unfortunately, has one of the lowest percentages of bioavailability of all available methods.
According to madebyhemp.com, “When consumed orally, CBD passes through the digestive system and circulates through the liver. The bioavailability of CBD is reduced during what is known as ‘first pass metabolism.’ When consumed, CBD is metabolized by the liver and in other sites such as the gastrointestinal tract, lungs, and blood. It reduces the amount of CBD that is present in the bloodstream.”
With edibles, the bioavailability of CBD is as low as 4-20 percent. However, some research shows that even though the bioavailability is lower from this method, given an equal active dosage, the effects may last longer.