It is important to know that nicotine is not a cause of cancer; rather, cancer-causing compounds in tobacco and tobacco smoke and carbon monoxide from the burning of tobacco cause diseases. The nicotine found in all nicotine replacement therapy products is regulated by the Food and Drug Administration, and these products are both safe and effective when used properly. The amount of nicotine you get from nicotine replacement therapy products is low, is delivered very slowly, and does not contain chemicals causing cancer or other diseases. Using nicotine replacement therapy for approximately 3 to 6 months is  a safe and effective way to help people quit smoking and stay quit. https://smokefree.gov/sites/default/files/pdf/mythsaboutNRTfactsheet.pdf