Empowering youth workers and youth organisations to contribute to reducing excessive alcohol and drug use, and their consequences on young people's well-being, physical and mental health, is of crucial importance to Europe. However, young people are often considered passive recipients of health promotion interventions, and the involvement of youth organisations in public health initiatives is insufficient.The proposed project - You4Health! - aims to address this need by providing youth workers with the necessary skills to implement effective health promotion interventions, and empower them to be actively involved in public health. The project team plans to do this by:1) Mapping the field of youth-led alcohol/drug health promotion interventions in order to provide a list of ready-to-use examples and case-studies;2) Realising You4Health!, an online training platform for youth workers. The platform will consist of sequenced training modules, guidelines, good practices and case studies, as well as ready-to-use materials for real-life situations, for the design, implementation and evaluation of effective youth-led health projects. All contents will be provided in English and translated into different languages.The You4Health! tools target youth workers and young people. Our approach is based on 'Co-production'. Any project output will be the result of collaboration between partner organisations and youth workers. An advisory group of youth workers from different countries will be actively involved from the beginning to collaborate as co-producer of project outputs, and to pilot the You4Health! web platform. Pilot's participants will represent the first group of youth workers to be trained, and with the aim of having a multiplying effect in their local communities. Overall, this will guarantee usability of the final products, foster a sense of ownership and contribute to achieving the highest reach among European youth organisations.The You4Health! project will increase youth workers' knowledge and critical thinking towards effective programmes, reduce implementation barriers for youth organisations, and increase the proportion of empowered youth workers in taking the initiative towards health promotion. In the long run, You4Health! will increase the number and quality of youth-led health projects and raise the broader conversation in society about young people's health issues, make young people more involved in public health, and ultimately have a positive impact on the young population health.