 Medications for smoking cessation are currently only effective in helping a minority of smokers quit. Drug development is slow and expensive, so there is much interest in optimizing the effectiveness of existing treatments and medications. Current standard doses of nicotine replacement therapy NRT are not effective for many smokers and in many cases provide less nicotine compared to when a smoker is smoking their usual number of cigarettes. The proposed study will test if a personalized dose of nicotine patch up to 84mg will improve quitting success in those who do not respond to a standard dose of NRT 21mg. 