Marijuana is a green, brown, or gray mixture of dried, shredded flowers, stems, seeds, and leaves of the hemp plant Cannabis sativa. There are nearly 600 known slang terms for marijuana or the use of marijuana, the most common being "pot" and "weed." It is usually smoked as a cigarette (called a "joint" or a "nail") or in a pipe or bong. Some users also mix marijuana into foods or use it to brew tea.
The main active chemical in marijuana is delta-9-tetrahydrocannabinol, or THC. THC is one of 70 cannabinoid chemicals in marijuana, and marijuana also contains more than 400 other chemicals, including some of the same carcinogens as tobacco smoke.
THC reaches peak levels in the body within 10 minutes of smoking. Intoxication lasts approximately two to three hours. Weakened mental ability, slow reaction times, and lack of coordination last up to 24 hours after each use of the drug.