Certain medicines contain per- and polyfluorinated alkyl compounds, known as PFAS, which are causing increasing environmental harm due to their long-lasting effects. A report by the University of Freiburg, commissioned by the German Environment Agency, shows that many PFAS-based active ingredients used in medicines can be replaced by alternative active ingredients. Based on the findings of the report, doctors will in future be able to give preference to prescribing PFAS-free medicines, where this is appropriate from a therapeutic point of view.