CBN

CBN (cannabinol, C₂₁H₂₆O₂, MW 310.43) is a non-enzymatic oxidative degradation product of THC that accumulates in aged, heat-exposed, or UV-exposed cannabis. Unlike other major cannabinoids it is not directly biosynthesized from CBGA. CBN is mildly intoxicating, with CB1 affinity roughly 10% that of Δ⁹-THC (Rhee et al., 1997). It binds CB2 with somewhat higher relative affinity, making it effectively CB2-preferring among the classical cannabinoids. CBN is widely marketed as a sedative "sleep cannabinoid," but a systematic review by Corroon (2021, Cannabis and Cannabinoid Research 6:366) concluded that the sedative reputation traces largely to a 1975 study (Karniol et al.) in which CBN was co-administered with THC; residual terpene oxidation products in aged cannabis, not CBN itself, may account for perceived sedation. Evidence for CBN monotherapy as a sleep aid remains low. → See also: THC, Decarboxylation, Myrcene.