PROJECT 3 (P3) P3 examines which features of ONPs increase abuse liability and product appeal in young adult vapers. To accomplish this, P3 will use virtual (Zoom) visits to recruit a nationwide sample of 320 current e-cigarette users aged 21-25 years who are not planning to quit vaping and open to using ONPs. We will conduct product appeal and abuse liability tests in a mixed factorial design varying ONPs by product type (nicotine pouch v. nonmedicinal gum) Å~ Flavor (mint v. fruit) Å~ Nicotine Concentration (high v. low). Aim 1 is to assess the sensory appeal Hypotheses: 1a) Based on preliminary data, we predict greater appeal (e.g., willingness to use again) and desirable sensory attributes for gum vs. pouches and low vs. high nicotine. Given that mint masks nicotine’s bitterness and irritating effects, we hypothesize:1b) Mint will suppress the sensory appeal-reducing (and irritation-enhancing) effects of high vs. low nicotine (nicotine Å~ flavor interaction). Aim 2 is to characterize ONP abuse liability. Using the highest rated mint and fruit ONPs from the previous appeal session, abuse liability for both flavors will be measured after 30-min standardized ONP self-administration via: i) positive subjective drug effects, withdrawal/urge relief, behavioral economic indices of ONP reward value, and novel dual use liability measures (i.e., motivation to use the ONP when e-cigarette use is constrained), and ii) naturalistic use after provision of study ONP in 1-week follow-up. Hypotheses: 2a) subjective drug effects, withdrawal/urge relief, ONP reward value, indices of demand, and naturalistic self-administration will be greater for high vs. low nicotine; 2b) ONP reward value, indices of demand, and naturalistic self-administration will be higher for gum (vs. pouch); 2c) ONP reward value, indices of demand, and naturalistic self-administration will be higher for mint than fruit, especially in the high nicotine condition (nicotine Å~ flavor interaction). Implications for regulation: If certain combinations of ONP types, flavors, and nicotine concentrations improve the user experience and enhance abuse liability, these products could encourage new ecigarette+ ONP dual use patterns (e.g., use ONPs at times when vaping is not possible). This could provide the FDA with evidence that denying marketing applications or prioritizing enforcement of illegal marketing for these specific ONPs could prevent AYAs who try ONPs from becoming persistent users with detrimental use patterns. FDA Scientific Areas: Behavior and Addiction.