Understanding the Influence of "Natural" Cigarillo Descriptors on Expectancies, Subjective Effects, Smoking Behavior, and Exposure: A human laboratory study - PROJECT ABSTRACT Tobacco companies are incredibly skilled at circumventing tobacco control regulations. This is what they have done with the development of a new generation of implied reduced harm claims positioning tobacco products as “natural,” evading federal regulations that prohibit tobacco companies from making explicit reduced harm claims. Current, former, and even non-users of tobacco believe that tobacco brands using the “natural” descriptor and related themes/descriptors are less harmful, healthier, and more attractive than their conventional counterparts. While the misleading nature of the “natural” descriptor is well understood in cigarettes, it has not been investigated in cigarillos, the second most commonly used combusted tobacco product. Sales of non-“natural” labeled cigars were flat between 2017-2021; however, sales of cigars labeled as “natural” increased by 14% during this time period, driving the overall increase in cigar sales. Cigarillo smoke contains higher concentrations of toxins and carcinogens than cigarette smoke, and sustained use is a cause of cancer. Despite their harm profile, cigars, including cigarillos, are commonly viewed as less harmful than cigarettes. One possible reason for this is the belief that cigars are perceived as more “natural”, perhaps driven by the increasing use of the term “natural” on packaging and advertising. Although sales of “natural” labeled cigarillos have surged, no research has yet assessed their addiction potential by examining the following: 1) health-risk expectancies motivating current and future cigarillo use; 2) subjective effects that reinforce repeated use; and 3) use patterns that increase nicotine and toxicant exposure (e.g., inhalation amount). Recruiting a diverse sample of young adult cigarillo users, the overall objective of this within-subjects human laboratory deception study is to examine the relationship between exposure to the “natural” descriptor on cigarillo advertising with health-risk expectancies, subjective effects, cigarillo smoking behavior, and toxicant exposure. Our central hypothesis is that cigarillos with a “natural” descriptor will increase product appeal and use behavior. Prior human laboratory research and online experimental studies, including our pilot work and preliminary data from MPI Pearson’s ongoing R01, have found that “natural” can affect health-risk expectancies and subjective effects for cigarettes establishing the scientific premise that the “natural” descriptor could affect such outcomes similarly for cigarillos. At the completion of this project, the expected outcomes are to have identified the addictive potential of “natural”-labeled cigarillos vs those without. The subjective appeal and reinforcing effects of tobacco use are important indicators of the neurobiological systems that underlie nicotine addiction and abuse liability and have been shown to motivate subsequent use. These results will have a positive impact because they will provide a strong evidence-base to inform product standards (packaging, labeling) for cigarillos (and other tobacco products), and will inform prevention messaging to reduce cigarillo appeal and correct misperceptions about perceived harm of “natural” labeled tobacco products.