If 1 cigarette has only mg of nicotine how can a 21 patch help you quit?

One cigarette contains more than 1 mg of nicotine. One Marlboro cigarette holds about 12 milligrams of nicotine and delivers about 1 to 2 milligrams to the smoker with each puff. It is more likely that a 21 mg patch would be the lowest strength available in a nicotine patch, and this would still deliver significantly more nicotine to a former smoker than a single cigarette. Higher nicotine patches might contain 35 or 52 mg of nicotine.