Marijuana contains hundreds of known compounds, the most famous of which is called THC - tetrahydrocannabinol. The main psychoactive component of the herb, THC, is directly responsible for changes in mood, perceptions and behavior that are associated with cannabis use. When processing THC from the body, the molecule is degraded in the liver to 11-nor-9-carboxy-tetrahydrocannabinol or THC-COOH - the primary THC metabolite.
This metabolite is the main molecule on which most "narcotic" marijuana tests are based. They are mostly held by law enforcement agencies but may be mandatory when applying for certain positions in state institutions, schools, and private companies. They are especially useful for parents who want to know if their child is using cannabis.
