5(6)-EpETE methyl ester is a derivative of 5(6)-EpETE which is stable enough to ship and handle routinely. 5(6)-EpETE methyl ester is a chemically less reactive derivative of 5(6)-EpETE. The active free acid can be generated from the methyl ester by careful base hydrolysis. Epoxy eicosatetraenoic acids (EpETEs) are the epoxygenase metabolites of EPA. A number of vicinal diol metabolites of EpETEs have been detected in the plasma of patients on marine oil dietary supplementation, while in subjects on a typical western diet these compounds are generally not detected. The specific biologic activity of 5(6)-EpETE and its methyl ester have not been documented.