This transdisciplinary project with KNMP, RIVM and several pharmacists focuses on promoting the sustainable use of psychotropic medications to minimize environmental harm. In response to the increasing use of these drugs and their impact on aquatic ecosystems, the research aims to address knowledge gaps about improper disposal, prescribing practices, and environmental risks. It involves systematic studies to assess the awareness of prescribers, pharmacists, and patients regarding sustainability, evaluate the environmental damage caused by specific psychotropic drugs, and test the effectiveness of simple educational interventions. Collaboration with key stakeholders ensures practical insights and innovative solutions, ultimately contributing to sustainable prescribing, usage, and disposal practices while reducing ecological harm.