The use of anabolic agents in food producing animals is prohibited within the European Union since 1988. The illegal use of natural steroid hormones control is however still a current challenge, especially regarding the limitations of existing screening methods. In this context, the present study aimed to develop a new screening approach based on the emerging 'untargeted profiling' concept, but with a special emphasis on steroids phase II conjugated metabolites, in the scope of revealing potential biomarkers signing a fraudulent administration of 4-androstenedione. After extraction and separation of the urinary glucuronide and sulfate steroid fractions, each one was analyzed separately by UPLC-MS/MS using the precursor ion scan acquisition mode. This approach was carried out in order to monitor product ion characteristic of sulfate (m/z 97) and glucuronide (m/z 113) functional groups, and then to fish for any potential conjugated steroid leading to these ionic species after fragmentation. After statistical analysis, 86 metabolites (33 from steroid compounds and 53 from other unknown substances) were highlighted as potential biomarkers of 4-androstenedione abuse. After application of several robustness criteria, 26 metabolites (whom 5 were unambiguously structurally identified), were finally selected to build a statistical model which could be used as new diagnostic tool for screening purposes. (C) 2011 Elsevier B.V. All rights reserved.