tetrahydrocannabinol tetrahydrocannabinol tetrahydrocannabinol (thc) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. although the chemical formula for thc (c21h30o2) describes multiple isomers, the term thc usually refers to the delta-9-thc isomer with chemical name (−)-trans-δ9-tetrahydrocannabinol. thc is a terpenoid found in cannabis and, like many pharmacologically active phytochemicals, it is assumed to be involved in the plant's evolutionary adaptation against insect predation, ultraviolet light, and environmental stress. thc was first discovered and isolated by israeli chemist raphael mechoulam in israel in 1964. it was found that, when smoked, thc is absorbed into the bloodstream and travels to the brain, attaching itself to endocannabinoid receptors located in the cerebral cortex, cerebellum, and basal ganglia. these are the parts of the brain responsible for thinking, memory, pleasure, coordination and movement. for the phytocannabinoid homologue of thc, that is much more potent than thc itself, see thcp. tetrahydrocannabinolinn: dronabinolclinical datatrade namesmarinol, syndrosother names(6ar,10ar)-delta-9-tetrahydrocannabinol; (−)-trans-δ9-tetrahydrocannabinol; thclicense data us fda: dronabinol dependenceliabilitylow - moderate 8–10%addictionliabilityrelatively low: 9%routes ofadministrationoral, local/topical, transdermal, sublingual, inhaleddrug classcannabinergicatc codea04ad10 (who) legal statuslegal status au: unscheduled: act, schedule 8 (controlled drug) br: class f (prohibited substances) ca: unscheduled de: dronabinol: anlage iii, δ9-thc: ii, other isomers and their stereochemical variants: i. (does not apply to thc as part of cannabis, which is regulated separately, see cannabis (drug)) uk: class b us: schedule ii as syndros, and schedule iii as marinol un: psychotropic schedule i /ii pharmacokinetic databioavailability10–35% (inhalation), 6–20% (oral)protein binding97–99%metabolismmostly hepatic by cyp2celimination half-life1.6–59 h, 25–36 h (orally administered dronabinol)excretion65–80% (feces), 20–35% (urine) as acid metabolitesidentifiers iupac name (6ar,10ar)-6,6,9-trimethyl-3-pentyl-6a,7,8,10a-tetrahydro-6h-benzochromen-1-ol cas number1972-08-3 ypubchem cid16078iuphar/bps2424drugbankdb00470 ychemspider15266 yunii7j8897w37skeggd00306 ychebichebi:66964 nchemblchembl465 ycomptox dashboard (epa)dtxsid6021327 echa infocard100.153.676 chemical and physical dataformulac21h30o2molar mass314.469 g·mol−13d model (jsmol)interactive imagespecific rotation−152° (ethanol)boiling point155–157°c @ 0.05mmhg, 157–160°c @ 0.05mmhgsolubility in water0.0028 mg/ml (23 °c) smiles cccccc1cc(c2c(c1)oc(32c=c(cc3)c)(c)c)o inchi inchi=1s/c21h30o2/c1-5-6-7-8-15-12-18(22)20-16-11-14(2)9-10-17(16)21(3,4)23-19(20)13-15/h11-13,16-17,22h,5-10h2,1-4h3/t16-,17-/m1/s1 ykey:cyqfcxcebyingo-iagownofsa-n y ny (what is this?) (verify) thc, along with its double bond isomers and their stereoisomers, is one of only three cannabinoids scheduled by the un convention on psychotropic substances (the other two are dimethylheptylpyran and parahexyl). it was listed under schedule i in 1971, but reclassified to schedule ii in 1991 following a recommendation from the who. based on subsequent studies, the who has recommended the reclassification to the less-stringent schedule iii. cannabis as a plant is scheduled by the single convention on narcotic drugs (schedule i and iv). it is specifically still listed under schedule i by us federal law under the controlled substances act for having "no accepted medical use" and "lack of accepted safety". however, dronabinol, a pharmaceutical form of thc, has been approved by the fda as an appetite stimulant for people with aids and an antiemetic for people receiving chemotherapy under the trade names marinol and syndros. medical uses further information: dronabinol not to be confused with droperidol. thc is an active ingredient in nabiximols, a specific extract of cannabis that was approved as a botanical drug in the united kingdom in 2010 as a mouth spray for people with multiple sclerosis to alleviate neuropathic pain, spasticity, overactive bladder, and other symptoms. nabiximols (as sativex) is available as a prescription drug in canada. in 2021, nabiximols was approved for medical use in ukraine. as of 2022, 38 states, three territories, and the district of columbia in the united states allow medical use of cannabis (in which thc is the primary psychoactive component), with the exception of idaho, iowa, wyoming, nebraska, wisconsin, indiana, tennessee, alabama, north carolina, south carolina, and georgia. as of 2022, the u.s. federal government maintains cannabis as a schedule i controlled substance under law, while dronabinol is classified as schedule iii in capsule form (marinol) and schedule ii in liquid oral form (syndros). pharmacology