Updated project metadata. Endocrine disruption (ED) can trigger far-reaching effects on environmental populations, justifying a refusal of market approval for chemicals with ED properties. For the assessment of ED effects on development and reproduction, regulatory decisions mostly rely on apical endpoints from in vivo testing with adult animals. Here, we present a rapid and reproducible data dependent proteomics approach for identifying comprehensive molecular fingerprints interfering with the sexual endocrine system in zebrafish (Danio rerio) embryos as an alternative to animal testing. For this, we have analysed methyltestosterone as model substances for androgenic perturbation in a modified zebrafish embryo toxicity test (zFET). These signatures allow for a definition of solid biomarkers as tools in screening approaches and for integration in chronic toxicity studies for identifying suspect ED substances, in the fish early life-stage test (OECD TG 210).