Marijuana is produced from the dried leaves and flowers of the cannabis plant. It contains THC, which is the psychoactive compound that produces marijuana's effects. THC is fat-soluble and can stay in the body for weeks after use. Marijuana can be smoked, ingested, or taken as a pill. Short-term effects include increased heart rate and feelings of euphoria, while long-term use may negatively impact the brain, lungs, and reproductive system. Marijuana is also illegal and its use can carry legal penalties.