Metabolizer is ChemAxon's metabolite enumeration and major metabolite prediction tool. Metabolite prediction provides ideas about the metabolic fate of molecules. Biodegradation deactivates drugs, activates pro-drugs and metabolites can have biological effects which may mean risk for living organs. Knowing metabolic fate early can help drug designers to improve the metabolic stability of compounds or to avoid toxicity risks.

Metabolizer's knowedge base is stored in biotransformation libraries. A library contains a set of generic reactions, rules to make transformations selective, examples, literature references ranking and some other data. Biotransformation libraries can be "plugged in" easily, and you can even create and use your own ones. A human xenobiotic phase I biotransformation library is built-in the application, however, for immediate use.

Metabolizer is part of ChemAxon's JChem package and a desktop application is installed by the JChem installer. is released in the form of a desktop application with graphical user interface (GUI). Command line tool and programming API are not yet available in the initial release.