Karen smith,   Thanks for your question.    Nicotine doesn't stay in your system very long.  Doctors like to use something called a half life to describe how long drugs and toxins remain in our systems before they are eliminated.  In the case of nicotine, the half life is one hour.  This means that it takes one hour for half of the nicotine to be broken down and eliminated.  In another hour, half of the remaining nicotine will be eliminated, leaving 25 % of the original amount left in the system.  Another hour later, will find 12.5% and so on.  In 6 - 8 hours the amount left is almost negligible.   Breakdown of nicotine occurs in the liver and lungs and the breakdown products are passed out of the body through the urine.    Please review our website for more information about nicotine, its addictive action and ways to kick the habit.   Martin Cane, M.D.