RecruitingDrug trialEffects of E-Cigarette Flavors on Adult E-Cigarette Users With Opioid Use DisorderThis study examines the effects of e-cigarette (EC) flavors among adults with opioid use disorder (OUD) receiving buprenorphine treatment who currently use e-cigarettes. Participants will smell and rate 11 EC flavors based on appeal, sensory characteristics, and likelihood of future use. Researchers will examine how different flavor profiles influence the appeal and reinforcing effects of ECs in this population. The goal is to identify EC flavors that may enhance the acceptability of ECs as a potential harm-reduction strategy among adults with OUD receiving buprenorphine treatment.