ABSTRACT: PROJECT 2 In the US, 18.5 million people smoke menthol cigarettes. The largest disparities in menthol cigarette use are between Black and white smokers. Rates are also higher among lesbian/gay and bisexual (LGB) smokers vs. straight smokers. FDA has proposed to ban menthol as a characterizing flavor in cigarettes. The benefits of a menthol ban could be dramatically amplified by a quit smoking campaign that gives menthol smokers the tools they need to quit smoking altogether, rather than switch to different cigarettes. The primary goal of Project 2’s proposed research as part of the UNC TCORS is to evaluate whether the benefits of a menthol ban could be amplified by a quit smoking campaign, with a focus on the priority populations of Black and LGB people who smoke menthol. The project will also provide rigorous causal evidence about the impact of a menthol cigarette ban on cigarette purchases. To achieve these goals, we will first develop a campaign to encourage priority menthol populations to quit smoking using our team’s multi-phase message development process involving expert feedback, focus groups with priority populations, and an experiment with a nationally representative sample of menthol smokers. We then will evaluate a menthol cigarette ban alone, and a ban paired with a quit smoking campaign, in an RCT. The RCT will leverage 3 locations of our team’s Mini Mart (i.e., a small convenience store designed for research), allowing for greater external validity of study findings and for measurement of consumer behavior in the context of a shopping trip. The Mini Mart is uniquely suited to test the interaction of interventions including policies and campaigns. Our proposed research will also shed light on the psychological mechanisms through which a menthol ban and campaign influence consumer purchasing behavior, using mixed-methods mediation techniques. This research will inform FDA’s menthol regulation and potential industry challenges to their proposed rule banning menthol as a characterizing flavor in cigarettes. Expected results of this project will include audience-informed campaign materials to encourage menthol cigarette smokers to quit smoking altogether, rigorous causal evidence of the impact of a menthol ban on cigarette purchases, and an understanding of whether a campaign can amplify the benefits of a menthol ban. This project aligns with the UNC TCORS Center Integrative Theme of building the science for effective regulation of and communication about tobacco flavored products disproportionately used by priority populations. This research addresses RFA-OD-22-004 Scientific Domains of behavior, communications, and impact analysis. We propose research in multiple priority areas of the RFA by using innovative methods to assess the impacts of a menthol ban and campaign in priority populations.