Metabolomic studies focus on the identification, quantification, and interpretation of metabolites. Like the fields of genomics, transcriptomics, and proteomics, metabolomics is essential to a systems-level understanding of complex biological phenomena. Metabolomics has shed light on the metabolic changes that accompany human disease, such as cancer, diabetes, and cardiovascular disease, as well as vital biological insights in numerous organisms. While human biofluids have been widely used in metabolomic studies, model organisms provide paths forward for studies that would otherwise be impossible or unethical in humans.