CBD

CBD (cannabidiol, C₂₁H₃₀O₂, MW 314.46) is the second most-abundant cannabinoid in most cultivars and the dominant cannabinoid in hemp chemotypes. It was first isolated by Adams, Hunt, and Clark (1940, Journal of the American Chemical Society 62:196) and its absolute stereochemistry was established by Mechoulam and Shvo (1963, Tetrahedron 19:2073). CBD is non-intoxicating but pharmacologically complex: it is a CB1 negative allosteric modulator (Laprairie et al., 2015, British Journal of Pharmacology 172:4790), a 5-HT1A agonist (Russo et al., 2005, Neurochemical Research 30:1037), a TRPV1 activator/desensitizer, a GPR55 antagonist, and a PPARγ ligand. The FDA approved purified CBD as Epidiolex in 2018 for Dravet and Lennox-Gastaut syndromes, and in 2020 for tuberous sclerosis complex, based on phase-3 RCTs showing significant seizure reductions. The popular label "non-psychoactive" is imprecise: CBD is non-intoxicating but does cross the blood-brain barrier and modulate mood and anxiety in some trials. → See also: CBDA, CBDV, CB1 receptor, 5-HT1A.