Tetrahydrocannabinol

Tetrahydrocannabinol
INN: Dronabinol
Clinical data
Trade namesMarinol, Syndros
Other names(6aR,10aR)-delta-9-Tetrahydrocannabinol; (−)-trans9-tetrahydrocannabinol
License data
Dependence
liability
Physical: Low
Psychological: Low–moderate
Addiction
liability
Relatively low: 9%
Routes of
administration
By mouth, transdermal, sublingual, inhalation
Drug classCannabinoid
ATC code
Legal status
Legal status
  • AU: Unscheduled: ACT, Schedule 8 (Controlled Drug)
  • BR: Dronabinol: A3; THC <30mg/ml: A3; others: F2 (prohibited).
  • 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))
  • NZ: Class B (medicine form)
  • UK: Class B
  • US: Schedule II as Syndros, Schedule III as Marinol, Schedule I as Δ9-THC in pure form
  • UN: Psychotropic Schedule I /II
    • SE: Förteckning II (Unscheduled when EU-approved industrial hemp <0,3% THC)
    • In general Rx only
Pharmacokinetic data
Bioavailability
  • Oral: 6–20%
  • Inhalation: 10–35%
Protein binding97–99%
MetabolismMostly hepatic by CYP2C
Metabolites11-OH-delta-9-THC, and others
Onset of actionWithin seconds to minutes when smoked
Elimination half-life1.6–59 h, 25–36 h (orally administered dronabinol)
Duration of action2–4 hours when smoked and 4–10 hours when taken orally
Excretion
  • 65–80% (feces)
  • 20–35% (urine) as acid metabolites
Identifiers
  • (6aR,10aR)-6,6,9-Trimethyl-3-pentyl-6a,7,8,10a-tetrahydro-6H-benzo[c]chromen-1-ol
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.153.676
Chemical and physical data
FormulaC21H30O2
Molar mass314.469 g·mol−1
3D model (JSmol)
Specific rotation−152° (ethanol)
Boiling point155–157 °C (311–315 °F) 0.05mmHg, 157–160°C @ 0.05mmHg
Solubility in water0.0028 mg/mL (23 °C)
  • CCCCCc1cc(c2c(c1)OC([C@H]3[C@H]2C=C(CC3)C)(C)C)O
  • 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?)  (verify)

Tetrahydrocannabinol (THC) is a cannabinoid found in cannabis. It 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 (−)-trans9-tetrahydrocannabinol. It is a colorless oil.

THC, also known pharmaceutically as dronabinol, is used medically to relieve chemotherapy-induced nausea and HIV/AIDS-related anorexia. Nabiximols, a botanical drug which contains THC, is used medically to treat symptoms of multiple sclerosis, including spasticity and neuropathic pain. THC acts as a partial agonist at CB1 and CB2 cannabinoid receptors.

THC can be administered orally, inhaled, or transdermally, with bioavailability and onset varying by route, and is extensively metabolized in the liver to active and inactive metabolites before being excreted in feces and urine. Side effects include red eyes, dry mouth, drowsiness, memory impairment, anxiety, and, with chronic use, cannabinoid hyperemesis syndrome. While human overdose is rare, THC can interact with other drugs and has a complex pharmacokinetic profile.

THC is classified variably under international and US law, with medical use approved in multiple countries. Research supports its effectiveness for spasticity and central pain in multiple sclerosis, though evidence for other neurological disorders is limited, and long-term high-dose exposure may carry uncertain toxicity risks.