Marijuana leaves the body slowly. The effects of smoking a cigarette last for hours, so someone who smokes at night may still be under the drug's influence the following morning. There are some tell-tale signs of marijuana use. Someone who has smoked a single marijuana cigarette may be in a talkative, outgoing mood and have food cravings. This is often followed by a period of sleepiness.
Users often show signs of paranoia.
Marijuana also impairs coordination, concentration, and short-term memory. Heavy users may smoke several marijuana cigarettes a day. High doses can produce hallucinations. Long-term use may lead to a lack of energy, motivation, and impairment of memory. These effects may linger even after the user stops using the drug.