tetrahidrocannabinol

Tetrahidrocannabinol, also known as delta-9-tetrahydrocannabinol (Δ9-THC), is the principal psychoactive component of Cannabis sativa. It acts on the endocannabinoid system, primarily as a partial agonist at the CB1 receptor in the central nervous system and at CB2 receptors in peripheral tissues.

Chemically, Δ9-THC has the formula C21H30O2 and a tricyclic dibenzopyran structure. It is lipophilic and is absorbed rapidly when cannabis is smoked or vaporized, producing quick onset, with oral use yielding a delayed and longer-lasting effect. The psychoactive effects include euphoria, altered perception, changes in time sense, and increased appetite.

Pharmacokinetically, THC is metabolized in the liver by cytochrome P450 enzymes (notably CYP2C9 and CYP3A4) to 11-hydroxy-THC, an active metabolite, and later to 11-nor-9-carboxy-THC (THC-COOH), which is inactive. The drug and its metabolites are mainly excreted in feces and urine and are highly lipophilic, leading to storage in adipose tissue. Elimination half-life varies with use and can be extended with chronic administration, contributing to prolonged detection times.

Medical and recreational use varies by jurisdiction. Recreationally, THC produces mood alteration, perception changes, analgesia, and antiemetic effects in some contexts. Medically, cannabinoids derived from or including THC have been used for chronic pain, cancer-related nausea, and appetite stimulation; approved prescription products include dronabinol and cnt nabilone in some regions.

Safety considerations include impaired driving, memory and coordination effects, anxiety or paranoia in some individuals, and potential for dependence with long-term use. Pregnancy and certain psychiatric conditions are generally advised against use.