Assessment of Soluble Epoxide Hydrolase Activity In Vivo: A Metabolomic Approach.

•Soluble epoxide hydrolase (sEH) converts several FFA epoxides to corresponding diols.•Epoxide-diol ratios correlated strongly with each other, suggesting these ratios all reflect changes in sEH activity.•A novel modeling approach to analyze all epoxide-diol ratios simultaneously, termed SAMI, was developed.•SAMI improves power in detecting changes in sEH activity in animals and humans when compared to individual ratio estimates.