RecruitingProcedureManipulating E-Cigarette Nicotine to Promote Public HealthThis clinical trial explores the manipulation of e-cigarette (EC) nicotine to promote public health. Researchers are trying to understand and gather information about how the strength, form, and structure of nicotine in products play a significant role in their potential for addiction and how they might affect health risks. The information gained from this study may allow researchers to understand how these aspects of nicotine influence the potential for addiction, how people puff on ECs, how the body processes nicotine, and any potential harmful effects it might have on health. Exploring these specific characteristics of nicotine may also determine if an EC product standard could help identify optimal nicotine levels for users.