DrugBank 3.0 is a comprehensive resource for 'omics' research on drugs, offering extensive data on drugs, their targets, and related biological information. It contains detailed information on drug nomenclature, ontology, chemistry, structure, function, pharmacology, pharmacokinetics, metabolism, and pharmaceutical properties. DrugBank 3.0 has been significantly expanded since its last update in 2008, with over 40 new data fields per drug entry, a 40% increase in data depth. These additions include illustrated drug-action pathways, drug transporter data, drug metabolite data, pharmacogenomic data, adverse drug response data, ADMET data, pharmacokinetic data, computed property data, and chemical classification data. DrugBank 3.0 also offers expanded database links, improved search tools for drug-drug and food-drug interactions, new resources for querying and viewing drug pathways, and hundreds of new drug entries with detailed patent, pricing, and manufacturer data. These enhancements have been complemented by improvements in the quality and quantity of existing data, particularly regarding drug target, drug description, and drug action data. DrugBank 3.0 represents the result of two years of manual annotation work aimed at making the database more useful for a wide range of 'omics' applications, including pharmacogenomics, pharmacoproteomics, pharmacometabolomics, and pharmacoeconomics. The database has grown significantly in the past five years, with a 40% increase in the number of data fields for each drug entry, a 130% increase in the number of computed structure parameters, an 80% increase in the number of external database links, and a 46% increase in the number of food-drug interactions. The database has also improved the quality of its existing data, with hundreds of drug descriptions, mechanisms of action, and pharmacological summaries either re-written or expanded. DrugBank 3.0 now includes detailed drug pathway diagrams, drug transporter information, drug carrier information, drug metabolite data, drug metabolizing enzyme data, QSAR data, chemical classification data, SNP-associated drug effects, and drug patent/pricing/manufacturer data. The database has also expanded its database linkages, with an average of 31 hyperlinks per DrugCard. DrugBank 3.0 also offers enhanced querying and viewing capabilities, including new browsing or search tools such as PathBrowse, GenoBrowse, ClassBrowse, ReceptorBrowse, and the Interax Interaction Search. These tools allow users to search for drugs, drug targets, metabolizing enzymes, carriers, and transporters, and to explore drug-action pathways and drug-drug or food-drug interactions. DrugBank 3.0 is a comprehensive and accessible drug information resource that should be much more useful for a wide range of 'omics' applications.DrugBank 3.0 is a comprehensive resource for 'omics' research on drugs, offering extensive data on drugs, their targets, and related biological information. It contains detailed information on drug nomenclature, ontology, chemistry, structure, function, pharmacology, pharmacokinetics, metabolism, and pharmaceutical properties. DrugBank 3.0 has been significantly expanded since its last update in 2008, with over 40 new data fields per drug entry, a 40% increase in data depth. These additions include illustrated drug-action pathways, drug transporter data, drug metabolite data, pharmacogenomic data, adverse drug response data, ADMET data, pharmacokinetic data, computed property data, and chemical classification data. DrugBank 3.0 also offers expanded database links, improved search tools for drug-drug and food-drug interactions, new resources for querying and viewing drug pathways, and hundreds of new drug entries with detailed patent, pricing, and manufacturer data. These enhancements have been complemented by improvements in the quality and quantity of existing data, particularly regarding drug target, drug description, and drug action data. DrugBank 3.0 represents the result of two years of manual annotation work aimed at making the database more useful for a wide range of 'omics' applications, including pharmacogenomics, pharmacoproteomics, pharmacometabolomics, and pharmacoeconomics. The database has grown significantly in the past five years, with a 40% increase in the number of data fields for each drug entry, a 130% increase in the number of computed structure parameters, an 80% increase in the number of external database links, and a 46% increase in the number of food-drug interactions. The database has also improved the quality of its existing data, with hundreds of drug descriptions, mechanisms of action, and pharmacological summaries either re-written or expanded. DrugBank 3.0 now includes detailed drug pathway diagrams, drug transporter information, drug carrier information, drug metabolite data, drug metabolizing enzyme data, QSAR data, chemical classification data, SNP-associated drug effects, and drug patent/pricing/manufacturer data. The database has also expanded its database linkages, with an average of 31 hyperlinks per DrugCard. DrugBank 3.0 also offers enhanced querying and viewing capabilities, including new browsing or search tools such as PathBrowse, GenoBrowse, ClassBrowse, ReceptorBrowse, and the Interax Interaction Search. These tools allow users to search for drugs, drug targets, metabolizing enzymes, carriers, and transporters, and to explore drug-action pathways and drug-drug or food-drug interactions. DrugBank 3.0 is a comprehensive and accessible drug information resource that should be much more useful for a wide range of 'omics' applications.