35 Years of GLP in Germany: A Brief Overview About Its Successful History

Good Laboratory Practice (GLP) emerged in the 1970s in response to serious deficiencies in the validity and reproducibility of preclinical safety data submitted in the USA. Non-adherence to scientific standards in the use of laboratory methods and the data generated, and even fraudulent practices, led to the establishment of binding regulatory standards, which were later adopted by the OECD as the "Principles of GLP", alongside the Council Decision on the Mutual Acceptance of Data (MAD). This framework, expanded to include compliance monitoring programmes and non-member country participation and has since formed the foundation for international harmonization of non-clinical safety testing. Germany, as an early adopter of the OECD GLP system, provides a prominent example of long-term implementation. Since the national compliance monitoring programme became legally binding in 1990, thousands of inspections were carried out in the meantime. German test facilities cover all OECD-defined areas of expertise and the German compliance monitoring authorities maintain rigorous inspection cycles in line with OECD recommendations, with a notable share operating for decades within the programme. This long-standing infrastructure in Germany contributes to the reliable and robust application of the OECD's GLP principles. This article presents a comprehensive overview of the historical development, international transposition and national application of GLP, using Germany as a case study after 35 years of implementation. By compiling regulatory milestones, structural data, and long-term monitoring outcomes, the publication aims to provide a transparent evidence base for assessing the effectiveness of GLP frameworks. The systematic presentation of these data serves both to document Germany's contribution to the international GLP landscape and to support ongoing discussions on harmonization, resource allocation, and future challenges in non-clinical safety assessment.