Tetrahydrocannabinol vs Cannabidiol: what is the difference?

How they differ

These two have the identical formula, C21H30O2, and identical weight, and one is intoxicating while the other is not. The difference is that THC's molecule closes into a ring that CBD leaves open, and only the closed form fits the CB1 receptor in the brain in a way that activates it. CBD instead acts indirectly at CB1 and on a scattering of other targets including serotonin receptors and TRPV1. THC is the compound cannabis is regulated for, and CBD is sold widely as a supplement in jurisdictions where THC is not. CBD is also the one with an approved prescription medicine built on it, for specific childhood epilepsy syndromes.

Side by side

Structural similarity 0.57 of 1, computed as a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.

Common questions

What is the difference between Tetrahydrocannabinol and Cannabidiol?

These two have the identical formula, C21H30O2, and identical weight, and one is intoxicating while the other is not. The difference is that THC's molecule closes into a ring that CBD leaves open, and only the closed form fits the CB1 receptor in the brain in a way that activates it. CBD instead acts indirectly at CB1 and on a scattering of other targets including serotonin receptors and TRPV1.

Do Tetrahydrocannabinol and Cannabidiol have the same formula?

Yes. Both are C21H30O2 at 314.5 g/mol. They are isomers: the same atoms arranged differently, which is why they behave differently despite weighing the same.