How long does it take for tobacco to leave your body system?

Nicotine: Nicotine metabolizes quickly in the body. Usually within 8 hours, also it depends on the amount someone smokes. The effects of smoking like if someone had copd- reversal of lung function may take 3- 6 months( provided there is not already a structural damage).

Nicotine effects: Phsyical nicotine withdrawl is complete usually 72 hrs or so from stopping. But blood tests can still detect evidence of smoking 7 to 10 days later. Urine tests can find evidence 3 to 4 days after stopping.