Editing Cannabinol (section)

===Pharmacokinetics===
When administered orally, CBN demonstrates a similar metabolism to Δ<sup>9</sup>-THC, with the primary active metabolite produced through the hydrolyzation of C9 as part of [[First pass effect|first-pass metabolism]] in the liver. The active metabolite generated via this process is called [[11-Hydroxycannabinol|11-OH-CBN]], which is 2x as potent as CBN, and has demonstrated activity as a weak CB2 [[Receptor antagonist|antagonist]]. This metabolism starkly contrasts that of Δ<sup>9</sup>-THC in terms of potency, given that [[11-Hydroxy-THC|11-OH-THC]] has been reported to have 10× the potency of Δ<sup>9</sup>-THC.

Due to high lipophilicity and first-pass metabolism, there is low [[bioavailability]] of CBN and other cannabinoids following [[oral administration]]. CBN metabolism is mediated in part by [[Cytochrome P450|CYP450]] [[Protein isoform|isoforms]] 2C9 and 3A4. The metabolism of CBN may be [[Catalysis|catalyzed]] by UGTs ([[Glucuronosyltransferase|UDP-glucuronosyltransferases]]), with a subset of UGT isoforms (1A7, 1A8, 1A9, 1A10, 2B7) identified as potential substrates associated with CBN [[glucuronidation]]. The [[bioavailability]] of CBN following administration via [[inhalation]] (e.g., smoking or vaporizing) is approximately 40% that of [[Intravenous therapy|intravenous administration]].

A small study of six cannabis users found a highly variable half life of 32&nbsp;±&nbsp; 17 hours upon intravenous administration.<ref>{{cite journal | vauthors = Johansson E, Ohlsson A, Lindgren JE, Agurell S, Gillespie H, Hollister LE | title = Single-dose kinetics of deuterium-labelled cannabinol in man after intravenous administration and smoking | journal = Biomedical & Environmental Mass Spectrometry | volume = 14 | issue = 9 | pages = 495–499 | date = September 1987 | pmid = 2960395 | doi = 10.1002/bms.1200140904 }}</ref> Similar to CBD, CBN is metabolized by the [[CYP2C9]] and [[CYP3A4]] liver enzymes and thus the half-life is sensitive to genetic factors that effect the levels of these enzymes.<ref>{{cite journal | vauthors = Stout SM, Cimino NM | title = Exogenous cannabinoids as substrates, inhibitors, and inducers of human drug metabolizing enzymes: a systematic review | journal = Drug Metabolism Reviews | volume = 46 | issue = 1 | pages = 86–95 | date = February 2014 | pmid = 24160757 | doi = 10.3109/03602532.2013.849268 | s2cid = 29133059 | url = https://zenodo.org/record/1093138 }}</ref>