Nicotine replacements don't contain any of the carcinogens (cancer-causing agents) that are found in cigarettes. This is why Nicorette and NicoDerm CQ are sold without a doctor's prescription, and why they have helped millions of smokers quit. Nicotine replacements give you a reduced amount of nicotine to help calm your cravings and irritability so you can focus on the emotional aspects of your habit.