This R01 proposal is responsive to priority areas #2 (Addiction) and #4 (Behavior) within RFA-OD-19-019. Although the FDA banned characterizing flavors in cigarettes, menthol cigarettes are still available to consumers. Menthol cigarette smoking has increased specifically in young adults (YA; defined here as ages 18-24), while non- menthol smoking has decreased in this age group, and the majority of new YA smokers initiate with a menthol cigarette. Experimentation with menthol cigarettes vs non-menthol cigarettes, is linked to greater likelihood of progressing to regular smoking and of nicotine dependence. Recently, FDA has announced its intention to the reduce the nicotine in cigarettes to minimally addictive or non-addictive levels. Notably, a reduced nicotine standard would apply to all cigarettes on the market, including menthol cigarettes, which account for 30% of the cigarette market share. Menthol's pleasurable taste and other sensory effects (cooling /soothing sensations in the throat) may contribute to a positive first smoking experience, a potential mechanism linking initiation with uptake and regular smoking. As such, a key unanswered question is whether menthol sustains or increases the reinforcing properties of cigarette smoking in YAs, despite a low-nicotine product standard. If the appeal and reinforcing properties of very low nicotine cigarette (VLNC) smoking is increased by menthol flavoring in YAs, beyond non-menthol VLNC smoking, this may facilitate progression to regular smoking among newer users. While controlled investigations have examined the differential reinforcing effects of smoking VLNCs vs NNCs, the majority have focused on established adults smokers but omitted YA new smokers, and few, if any, have specifically examined differential appeal for smoking menthol vs non-menthol VLNCs. To address this knowledge gap, we will recruit 100 menthol YA smokers who started smoking regularly in the past 6-months, and measure appeal/reinforcement for smoking both menthol and non-menthol VLNCs and the impact of appeal/reinforcement on tobacco purchasing behavior using a well-validated Experimental Tobacco Marketplace (ETM) paradigm. Appeal/reinforcement will be assessed via two complementary measurement paradigms: one in the laboratory and the other in the natural environment using ecological momentary assessment (EMA). Laboratory studies provide a great deal of efficiency and internal control, allowing for causal inference of acute subjective response; while EMA allows for similar causal sequencing of behavior, but in an ecologically valid format. It is hypothesized that, compared to non-menthol VLNCs, menthol VLNCs will show greater appeal/reinforcement, both in the laboratory and via EMA, and appeal will predict tobacco purchasing behavior and preferences simulated in the “real world” via the ETM. This research will isolate the unique effects of menthol in smoking, beyond a reduced nicotine standard, and will help inform regulatory decisions about the abuse liability of menthol VLNCs and the use of flavors in other tobacco products in future studies.