What is the Bioavailability of CBD?

What is the Bioavailability of CBD?

CBD is available in many forms, including tinctures, edibles, capsules, and vape oils. The various means of consumption make CBD a versatile compound. With CBD products, you can cater to your supplement preferences and wellness goals.

Your choice of delivery method will determine the strength and distribution of CBD in your system. How you take CBD also has an effect on the bioavailability of a compound. The bioavailability of a substance is the percentage that is absorbed into the bloodstream after any other processing in the body.

Intravenous administration is said to have a 100% bioavailability; additional methods are compared to this route to create a ratio for the percentage bioavailability. While the bioavailability percentages vary between studies, there is a commonality between many. The following is an overview of the bioavailability of three of the most popular methods of CBD consumption: oral, sublingual, and inhalation.


Oral consumption of CBD can include products such as capsules, edibles, and oils. This method is popular due to its ease of use. Oral consumption is a quick and familiar method that is used for many supplements.

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. This reduces the amount of CBD that is present in the bloodstream.

The bioavailability of THC through oral consumption ranges from 4-20%. Sufficient data is not available for the bioavailability of CBD, which is why researchers are enthusiastic about the abundance of CBD research that is currently being conducted. As mentioned previously, factors such as absorption and metabolism are responsible for the low bioavailability.

While oral consumption has a lower bioavailability than other methods, it has been shown to have longer lasting effects.


Sublingual (under the tongue) consumption can be performed with products such as tinctures, concentrates, lozenges, and sprays. You may notice that many CBD oils recommend sublingual use rather than oral consumption due to its effectiveness.

When consumed sublingually, a substance is absorbed through the mucous membrane under the tongue. Capillaries in the connective tissue diffuse the substance, which then enters the bloodstream. In this method, the substance bypasses the first-pass metabolism. This accounts for a higher bioavailability than oral consumption. There is sufficient data to support that sublingual administration has a higher bioavailability than oral consumption; however, there are no specific percentages available.


CBD can be inhaled safely in the form of a vape oil and with a vaporizer pen. Vaping is a relaxing method that has gained popularity in the past years. It’s especially popular now that you can getnatural CBD vape oils, rather than unhealthy VG/PG blends.

During the method of vaping, CBD enters the bloodstream through the lungs. To explain this process, we’re going to get a bit science-y.

all stars space GIF by StarTalk Radio with Neil deGrasse Tyson

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. Again, this method bypasses the first-pass metabolism and therefore can have a higher bioavailability than oral consumption.

The bioavailability of inhalation of THC is reported to be as high as 56%. Therefore, inhalation can have a higher bioavailability of sublingual administration as well. However, this number ranges greatly due to the dynamics of smoking. The size and spacing of puffs, hold time, and volume of inhalation can greatly affect the level of bioavailability.

Inhaling vaporized CBD oil is a quick and efficient method. Since the oxygen is entering the bloodstream directly, the effects of CBD are quickly present.

Other Factors

All methods are affected by the hydrophobic properties of CBD oil. CBD oil does not readily dissolve in water and, for that reason, it diffuses out of the bloodstream and collects in fatty tissues. This reduces the amount of active CBD in the system, therefore lower bioavailability. Dosage and potency will also affect the bioavailability of a substance.

Bioavailability affects everything we consume, including food and other substances. While a low bioavailability may seem discouraging, it is quite the opposite. Varying bioavailabilities gives the consumer options. A lower amount of CBD can work well for some while higher amounts work well for others. Varying potencies makes CBD accessible for a wide range of people.

CBD Serving Size

The best CBD method will vary from person to person. When first trying CBD, is it best to start with the serving size on the label. If after a week the effects are not where you’d like them to be, increase the serving size for another week. Continue this process until you are happy with the results. Check out our other blog to learn more about CBD serving sizes.

Quality CBD Oil

Most importantly, the CBD content is dependent on the quality of the CBD oil. High-quality CBD oil will be consistent and will provide the level of CBD that is advertised. Be sure to purchase CBD products from a reputable source that has readily available information about their products. A COA is a great way to ensure what is on the package is what is in the product. This will ensure that you are receiving a quality product that will perform optimally.


What method of CBD consumption have you found to work well for you? Leave a comment below!

Back to blog