Asthma recently has been described as a disorder of multiple subphenotypes despite a common symptom presentation. These subphenotypes have differing molecular pathways and discovering these differences may lead to better diagnosis strategies and new treatments. Most studies investigating asthma pathways are driven by the scientist's own theories and experience and thus, are considered biased. Metabolomics, an exciting and innovative discipline, represents an unbiased, hypothesis free approach to defining a molecular phenotype of asthma.