Many people use both cigarettes and e-cigarettes (dual use) and want to quit both. However, little is known about the best way to support individuals who want to quit dual use. This study will test different doses of nicotine replacement therapy (patches and lozenges), a medication typically used for quitting smoking, to see which dose is best for people using both cigarettes and e-cigarettes. This study will also see if quitting cigarettes and e-cigarettes can lead to changes in health that might prevent cancer.