BackgroundEvidence from clinical research indicates that men and women can differ in response to drug treatment. The knowledge database Janusmed Sex and Gender was developed to illuminate potential sex and gender differences in drug therapy and, therefore, achieve a better patient safety. The database contains non-commercial evidence-based information on drug substances regarding sex and gender aspects in patient treatment. Here, we describe our experiences and reflections from collecting, analyzing, and evaluating the evidence.Janusmed Sex and GenderSubstances have been systematically reviewed and classified in a standardized manner. The classification considers clinically relevant sex and gender differences based on available evidence. Mainly biological sex differences are assessed except for gender differences regarding adverse effects and compliance. Of the 400 substances included in the database, clinically relevant sex differences were found for 20%. Sex-divided data were missing for 22% and no clinically relevant differences were found for more than half of the substances (52%). We noted that pivotal clinical studies often lack sex analyses of efficacy and adverse effects, and post-hoc analyzes are performed instead. Furthermore, most pharmacokinetic analyses use weight correction, but medicines are often prescribed in standard doses. In addition, few studies have sex differences as a primary outcome and some pharmacokinetic analyses are unpublished, which may complicate the classification of evidence.ConclusionsOur work underlines the need of sex and gender analyses, and sex-divided data in drug treatment, to increase the knowledge about these aspects in drug treatment and contribute to a more individualized patient treatment.