The NIDA Clinical Trials Network has a free, online training course to prepare research staff to conduct substance use clinical trials with human participants. The 12 modules of the Good Clinical Practice course are based on the principles of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use and the Code of Federal Regulations for clinical research trials in the United States. Users may take the course at their own pace and download and print modules to study offline. Users are required to complete a quiz following each module, and must pass with at least 80% accuracy (unless 100% accuracy is required by their institutional review board). Users who pass will be able to print a certificate of completion that is valid for 3 years within the NIDA Clinical Trials Network. Learn more about the Good Clinical Practice course.