THC

Tetrahydrocannabinol (THC)
INN: dronabinol

Clinical data
Trade names	Marinol
License data	US FDA: Dronabinol
Pregnancy category	US: C (Risk not ruled out)
Dependence liability	8–10% (Relatively low risk of tolerance)
Addiction liability	Low
Routes of administration	Orally, local/topical, transdermal, sublingual, inhaled
ATC code	A04AD10 (WHO)
Legal status
Legal status	AU: S8 (Controlled) CA: Schedule II DE: Anlage I (Controlled) UK: Class B US: Schedule I, Schedule II as Cesamet, and Schedule III as Marinol
Pharmacokinetic data
Bioavailability	10–35% (inhalation), 6–20% (oral)
Protein binding	97–99%
Metabolism	Mostly hepatic by CYP2C
Biological half-life	1.6–59 h, 25–36 h (orally administered dronabinol)
Excretion	65–80% (feces), 20–35% (urine) as acid metabolites
Identifiers
IUPAC name (−)-(6aR,10aR)-6,6,9-Trimethyl-3-pentyl-6a,7,8,10a-tetrahydro-6H-benzo[c]chromen-1-ol
Synonyms	(6aR,10aR)-delta-9-tetrahydrocannabinol
CAS Number	1972-08-3 Y
PubChem (CID)	16078
IUPHAR/BPS	2424
DrugBank	DB00470 Y
ChemSpider	15266 Y
UNII	7J8897W37S Y
ChEBI	CHEBI:66964 N
ChEMBL	CHEMBL465 Y
ECHA InfoCard	100.153.676
Chemical and physical data
Formula	C21H30O2
Molar mass	314.469 g/mol
3D model (Jmol)	Interactive image
Specific rotation	−152° (ethanol)
Boiling point	157 °C (315 °F)
Solubility in water	0.0028, (23 °C) mg/mL (20 °C)
SMILES CCCCCc1cc(c2c(c1)OC([C@H]3[C@H]2C=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 Y Key:CYQFCXCEBYINGO-IAGOWNOFSA-N Y
NY (what is this?)

Tetrahydrocannabinol (THC, dronabinol by INN), or more precisely its main isomer (−)-trans-Δ⁹-tetrahydrocannabinol, is the principal psychoactive constituent (or cannabinoid) of cannabis. It can be a clear, amber or gold colored glassy solid when cold, which becomes viscous and sticky if warmed.

Like most pharmacologically-active secondary metabolites of plants, THC in Cannabis is assumed to be involved in self-defense, perhaps against herbivores. THC also possesses high UV-B (280–315 nm) absorption properties, which, it has been speculated, could protect the plant from harmful UV radiation exposure.

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 signed by the US Congress in 1970 .

A pharmaceutical formulation is available by prescription in the U.S. and Canada under the brand name Marinol.