When tobacco is smoked, the average smoker takes in 1–2 milligrams of nicotine per cigarette. Nicotine rapidly reaches peak levels in the bloodstream and enters the brain. A typical smoker will take 10 puffs on a cigarette over the roughly 5 minutes that the cigarette is lit. Thus, a person who smokes about 1 pack (20 cigarettes) daily gets 200 “hits” of nicotine to the brain each day.
Among those who do not inhale the smoke—such as cigar and pipe smokers and smokeless tobacco users—nicotine is absorbed through mucous membranes in the mouth and reaches peak blood and brain levels more slowly.