Compound C demonstrates how AWESOM can assist scientists in identifying the metabolites of new compounds. In a recent study of etrasimod's metabolism in humans , traces of up to 31 metabolites were detected in plasma, feces, and urine; however, only 14 of these were "definitively or tentatively" identified. The proposed metabolic pathways confirm that two of the SOMs identified by AWESOM correspond to experimentally confirmed SOMs. More importantly, the atoms with elevated total uncertainty scores point to likely sites where experimental methods could not precisely determine the exact location of the SOMs -and, consequently, the exact structure of the metabolites. This includes the oxidation of the central cyclopentindole moiety and a second oxidation on the terminal cyclopentane ring, marked as "putative SOMs" in Figure . This example shows how AWESOM can guide experimentalists in conducting focused complementary studies on specific atoms to fully elucidate the structures of all metabolites of a compound, ultimately saving both time and resources. This work presents AWESOM, a GNN-based model for predicting phase 1 and 2 SOMs in xenobiotics focusing on uncertainty estimation. Unlike previous approaches using related technologies, AWESOM provides a comprehensive prediction of potential SOMs across a wide range of xenobioticsmetabolizing enzymes and generates atom-specific uncertainty scores, offering valuable insights into the confidence of its predictions.