When someone takes CBD oil, a capsule or another orally consumed CBD product, it is easy to assume that the amount swallowed is the amount the body receives. However, human physiology tells a considerably more complicated story. Between swallowing CBD and its arrival in the bloodstream, several biological processes determine how much of the original compound becomes available to circulate through the body. Understanding this journey helps explain why CBD absorption varies between individuals, why food can influence its availability and why researchers continue investigating different cannabinoid delivery technologies.