THC is psychoactive while CBD is not. While both compounds are cannabinoids, they each interact with the body in different ways. THC directly engages the cannabinoid receptor 1 (CB1), which is concentrated largely in the central nervous system.
CBD, however, doesn’t engage CB1 in the same way. As explained by neurologist and medical researcher Dr. Ethan Russo in an interview with Project CBD:
“[CBD] doesn’t tend to bind directly to what’s called the orthosteric site [on cannabinoid receptors] where THC binds. Rather, it binds on what’s called an allosteric site, another site on the receptor, and so it alters the binding of both THC and the endogenous cannabinoids, the endocannabinoids.”
So, what’s the verdict in a THC vs. CBD mashup? CBD and THC both connect on receptors in different locations. While THC directly engages the cannabinoid through the orthosteric site, CBD seems to regulate or fine tune that interaction by connecting to a separate receptor location.
Read more >>> Source: CBD: Everything You Need To Know About Cannabidiol