Bioavailability refers to the amount of a substance that is absorbed into the bloodstream after it has been consumed. When it comes to cannabidiol (CBD), each method of consumption produces varying levels of bioavailability. Bioavailability is important because increased CBD absorption into the bloodstream makes for a more effective product.
Edibles, for example, have a lower bioavailability because much of the CBD must be digested before it enters the bloodstream; this is called “first-pass metabolism.” Conversely, inhaled CBD results in a higher bioavailability because the cannabinoid is absorbed through the lungs and does not have to pass through the digestive tract before it enters the bloodstream.
Oral CBD, like in oils and tinctures, typically has a low bioavailability compared to other delivery forms. This is an important concept to understand because, in order for CBD to be effective, it must reach cannabinoid receptors and the other pathways in the brain and body.
Thanks to recent research, however, there is good news on how we can improve the bioavailability of oral CBD.
Researchers at BioTeSys GmbH recently conducted the first clinical trial testing the bioavailability of oral CBD. This study looked at whether the absorption of oral CBD could be improved by using a more effective delivery system.
Sixteen participants (half men and half women) were each given a single oral dose of 25mg of CBD via a self-emulsifying drug delivery system (SEDDS) called VESIsorb®, which was developed by Vesifact AG (Baar, Switzerland). After 14 days, the same participants were given CBD diluted with medium-chain triglycerides (MCTs) to compare the effects on bioavailability; this dose was called MCT-CBD. To control for the effect of food, participants had to fast before receiving these doses.
The researchers found that SEDDS-CBD resulted in higher bioavailability compared to MCT-CBD. More specifically, the blood plasma levels of those in SEDDS-CBD group were 4.4 times higher than the MCT-CBD group.
SEDDS contain several substances that contain hydrophilic (“fat-loving”) solvents. This mixture can break down oil into droplets, just like your gastrointestinal tract does to digest fats. In this way, SEDDS can help get more CBD into your bloodstream.
CBD is increasingly being sought after to alleviate many symptoms, such as pain and inflammation, while promoting better overall health. The findings of this study suggest that individuals who use oral CBD may not have to consume as much of a CBD product in order to reap its benefits thanks to a heightened level of bioavailability through an innovative delivery system. Further research and development is required before public use but these data and technique are very promising.
- Xu C, et al. Pharmacokinetics of oral and intravenous cannabidiol and its antidepressant-like effects in chronic mild stress mouse model,” Environ Toxicol Pharmacol. 2019;70:103202.
- Knaub K, et al. A novel self-emulsifying drug delivery system (SEDDS) based on VESIsorb® formulation technology improving the oral bioavailability of cannabidiol in healthy subjects. Molecules. 2019;24(16):2967.