Abstract There has been a steady increase in cannabis use among US adolescents over the past decade. Perceptions of risk, specifically the belief that cannabis use is not harmful, may contribute to this increased use. The purpose of this study was to evaluate parental, school, and peer influence as protective factors in perceiving there is risk of harm from monthly cannabis use. Using the 2017 National Survey on Drug Use and Health (NSDUH), the study outcome was self-reported perceived risk of harm from monthly cannabis use amongst adolescents between ages 12 and 17. The exposures were parental monitoring and support, perception of school importance, extracurricular activity participation, peer...