IISUP I: Welcome to Prevention is a self-paced, online course introducing participants to youth substance use prevention. Participants of this course will explore why prevention matters, including the rates, effects, and consequences of youth substance use. Participants will also examine milestones and trends of substance use in our society over time, how prevention efforts have evolved throughout history, and the components of effective prevention. This course consists of six modules. Estimated completion time for the entire course is 3 hours. Estimated completion time for each module is 30 minutes.