Project 1, Study 1 will evaluate the relationship between nicotine yield of very low nicotine content cigarettes and cigarettes smoked per day, nicotine exposure, discomfort/dysfunction, other health-related behaviors, nicotine/tobacco dependence, biomarkers of tobacco exposure, intention to quit, compensatory smoking, other tobacco use, cigarette characteristics, cognitive function, cardiovascular function, and perceived risk. We will also consider differences between conditions in compliance with product use.