Cannabidiol (CBD), and Tetrahydrocannabinol (THC) are the two predominant cannabinoids found in marijuana and while they have key differences, it’s important to understand their similarities as well. The major difference most people think about is typically that THC is psychoactive, and CBD is non-psychoactive.
To understand why this is the case, it’s important to look at the similarities and differences in their chemical structure. (Please excuse my bad picture editing abilities)
In the figures above the red areas represent where CBD and THC are identical, whereas the blue areas illustrate where they differ. Despite my childlike animation abilities, it is still clear to see that these two compounds are more similar than different.
Interesting Fact: CBD and THC actually have the same exact chemical composition; they only differ in the way these atoms are arranged. Both their molecular formulas are C21H30O2
That rearrangement of atoms is why these two compounds may look similar but result in a different clinical response because it alters how they react with our bodies’ endogenous receptors. THC in most cases stimulates our cannabinoid receptors (CB1 and CB2), whereas CBD in most cases blocks or modulates the activity of these receptors.
In a very basic way of looking at it, cannabinoid receptors are highly concentrated in the areas of our brain that are responsible for thinking, memory, and coordination and when THC binds to these receptors there is a change in their normal function (psychoactive). CBD however doesn’t bind these receptors and can actually block THC from exerting its effect (non-psychoactive).
The similarity in their structure is why they migrate to similar areas of our bodies, but that small difference drastically effects their respective physiologic response and how they react with one another. As always feel free to reach out for clarification or suggested follow-up topics!