Nicotine patches and gums don't change your brain chemistry.
These non-prescription products help people break the habit of lighting up throughout the day without having to deal with nicotine withdrawal. At least a decade before antidepressant options were available, smokers were using nicotine replacement to get through the trial of withdrawal from smoking.
Transdermal patches don't give you the kick that smoking does: Instead of the 10-second delivery system that cigarettes provide, the patches will deliver the drug steadily and evenly. If you wear them at night, you might have strange dreams, but you're less likely to wake up wanting that morning smoke.
Nicotine gum, on the other hand, does give you that occasional kick. You use nicotine gum by biting it a couple of times, then holding it in your mouth and biting again whenever a craving kicks up. You start with one piece every hour or two, then scale down to one piece every four to eight hours.
Even though quitters are only supposed to use the replacement therapies for 12 to 24 weeks, Dr. Steven A. Schroeder says that it's better to use them longer if you need to than to start smoking again.