Upon first inhaling smoke from a cigarette, the nicotine reaches the person’s brain in under 10 seconds, and it reaches the central nervous system in under five minutes. The initial influence on a person’s brain depends on a host of circumstances, but in most cases nicotine acts as a mild depressant. Nicotine is a fast-acting chemical, and is quickly used by the human body. All traces of nicotine are usually undetectable in a person within a few days after a final cigarette. The total length of time a person has been a smoker, combined with their metabolism and other physical characteristics, will determine how long it will take for the last traces of nicotine to leave the body.
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