DOSE-UP: Dose Optimization for Smoking and E-Cigarette Use Pharmacotherapy

This randomized clinical trial evaluates the effectiveness of augmented-dose combination nicotine replacement therapy (NRT) versus standard-dose NRT and no-NRT control for cessation of dual combustible cigarette (CC) and electronic cigarette (EC) use. Adults who currently engage in dual use and are motivated to quit both products will be assigned to one of three 12-week interventions: (1) no pharmacotherapy (behavioral support only), (2) standard-dose NRT (21 mg nicotine patch + 4 mg lozenges, 5-20/day), or (3) augmented-dose NRT (21 mg + 14 mg patches + 4 mg lozenges, 5-30/day). All groups receive evidence-based behavioral support through the EX Program. Primary outcomes include biochemically confirmed dual abstinence and CC-only abstinence at 12 and 24 weeks. A subset of participants will provide blood and saliva samples to assess DNA damage biomarkers associated with tobacco use and cessation.