Nicotine patches can help you stop smoking. When you apply the patch, nicotine passes through your skin into the body, replacing the nicotine you would normally get from smoking. As your body adjusts to not smoking, you should reduce the size of the patch over a period of 12 weeks, until you no longer need to use them. This nicotinell no. 3 patch is the final stage in using the patches, and should only be used after using patch no 1 and patch no.2. Not to be used if you suffer from serious heart disease, are pregnant or breastfeeding.