Cannabis

Eating 13: The blood-brain barrier

As we have seen, THC molecules are highly fat-soluble. That means they are easily absorbed into fatty tissue. As a result, THC molecules move easily through the fatty tissues of the brain.

They are also small enough to easily penetrate the vascular walls of the blood-brain barrier, even though these are better protected against foreign substances than other blood vessels in the body. Only now can the THC molecules affect the workings of the brain.