Cannabidiol lymphatic transport after oral administration assessed using a novel thoracic lymph duct cannulated conscious pig model.

Researchers wanted to understand how cannabidiol (CBD), a major component of cannabis, moves through the body's lymphatic system—a network of vessels that absorbs fats and other substances from food and supplements. Most previous studies on this process used anesthetized rats, but rats are quite different from humans in their anatomy and physiology. In this innovative study, scientists surgically placed a small tube into the thoracic lymph duct (a major lymphatic vessel) in conscious pigs, which are considered a better biological model for understanding human physiology. They then gave pigs two different forms of CBD—one dissolved in sesame oil and one as a modern nanoemulsion formulation—and measured how much CBD ended up in the bloodstream and lymph over time.

The results showed that CBD has relatively low overall bioavailability (the amount that actually enters the bloodstream) at around 6-9%, but surprisingly, a significant portion of the CBD that does get absorbed travels through the lymphatic system rather than directly into the blood. Notably, the lymphatic transport patterns differed between pigs and rats, suggesting that previous rat studies may not accurately predict how CBD moves through the human body. The nanoemulsion formulation showed more consistent results between species, which has important implications for how CBD products are formulated and absorbed.

These findings are significant for both researchers and cannabis users because they highlight how formulation matters—different ways of preparing CBD can substantially affect how your body absorbs it. The research also suggests that animal models closer to humans (like pigs) are essential for accurately predicting how cannabinoid medicines will work in people, potentially leading to better CBD products and more reliable dosing guidelines in the future.