Tetrahydrocannabinol

The chemical compound tetrahydrocannabinol (THC) is a psychoactive substance found in cannabis.

Its molecular formula is C₂₁H_30</font>O₂, with a molecular weight of 314.45. Its IUPAC name is (6aR-trans)-6a,7,8,10a-tetrahydro-6,6,9-trimethyl-3-pentyl-6H-dibenzo[b,d]pyran-1-ol, more common names are Δ⁹-tetrahydrocannabinol (sometimes also Δ¹-tetrahydrocannabinol, using different numbering scheme) and others. It has a boiling point of 473.15 K (200 �C, 392 �F). It has a LD₅₀ of 1270 mg/kg (male rats), 730 mg/kg (female rats) orally (administered dissolved in sesame oil).

Its actions on the body are the result of its binding to a receptor, which was known as the cannabinoid receptor. Since cannabinoids are not naturally produced in the human body, the search began for this receptors' endogenous ligand (the substance that normally binds to it), leading to the eventual discovery of anandamide. Studies of the distribution of the receptors in the brain explain why toxicity of THC is so low (i.e., the LD₅₀ of the compound is so large): parts of the brain that control vital functions such as respiration do not have many receptors, so are relatively unaffected even by doses larger than could ever be ingested under any normal conditions.

Effects include relaxation, euphoria, altered space-time perception, enhancement of visual, auditory, and olfactory senses, disorientation, and appetite stimulation.

A number of studies indicate medical benefits for cancer and AIDS patients by increasing appetite and decreasing nausea, blocking the spread of some cancer-causing Herpes simplex viruses (Δ⁹). It has been shown to assist some glaucoma patients by reducing pressure within the eye, and is used, in the form of cannabis by a number of multiple sclerosis patients for relieving spasm. Other studies indicate a variety of negative effects associated with constant, long-term use, including memory loss, depression and loss of motivation. The long-term effects of THC on humans is highly disputed, and the issue is politicized because of its status as a schedule I drug according to the Controlled Substances Act (other tetrahydrocannibinol analogues such as Delta-6-Tetrahydrocannibinol are also listed in the Controlled Substances Act.)

Since September 1, 2003, the medicine Dronabinol (which contains THC) is available in Dutch pharmacies, for cancer and AIDS patients. An American analogue called Marinol is also available.

Tetrahydrocannabinol

See also