This is a smoking cessation study which is examining varenicline for use in reducing or quitting e-cigarettes. Half of the participants will receive a placebo pill and half will receive varenicline. All participants will be asked to complete daily, brief REDCap EMA diaries (to report e-cigarette use, other tobacco use, and record videos of medication taking) and attend research visits every 3 weeks (i.e., weeks 3, 6, 9, 12) to complete additional assessments and receive compensation for doing so.

This is a smoking cessation study which is examining varenicline for use in reducing or quitting e-cigarettes. Half of the participants will receive a placebo pill and half will receive varenicline. All participants will be asked to complete daily, brief REDCap EMA diaries (to report e-cigarette use, other tobacco use, and record videos of medication taking) and attend research visits every 3 weeks (i.e., weeks 3, 6, 9, 12) to complete additional assessments and receive compensation for doing so.

Eligible participants (ages 18+ whom have daily cigarette use) will attend an in-person assessment (though some aspects of the study, including consent, can be completed remotely). Participants will submit a breath sample for assessment of expired carbon monoxide. Approximately 5-7 days after completion of the in-person assessment, participants will meet with research staff. A medical clinician will meet with the participant to present a smoking cessation treatment recommendation along with resources. Participants will also complete surveys to assess their treatment preferences, motivation, and self-efficacy following receipt of the recommendation.

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.