Use of Nicotine Pouches Among Daily Smokers

The purpose of this clinical trial is to understand the health effects of a new oral nicotine pouch, and also to understand if this product can help reduce traditional cigarette smoking. The main aims are: 1. Understand the impact of nicotine pouch use on toxicant exposure biomarkers, and indicators of potential harms to health. 2. Examine the influence of nicotine pouch use on conventional tobacco product use (cigarettes). Participants will be randomized to one of six nicotine pouch groups (3 nicotine strengths, each with 2 potential flavors) to use over 16 weeks and asked to reduce their cigarette smoking over that time by at least 75% by substituting with the use of the nicotine pouches. Researchers will compare the outcomes of the different nicotine pouch strengths and flavors to each other. Participants will be asked to complete study questionnaires and provide urine, exhaled carbon monoxide, and mouth cell samples, and other health measurements.