5(6)-EET is a fully racemic version of the enantiomeric forms biosynthesized from arachidonic acid by cytochrome P450 enzymes. In solution, 5(6)-EET degrades into 5,6-DiHET and 5(6)-δ-lactone, which can be converted to 5(6)-DiHET and quantified by GC-MS. In neuroendocrine cells, such as the anterior pituitary and pancreatic islets, 5(6)-EET has been implicated in the mobilization of calcium and hormone secretion. 5(6)-EET is an inhibitor of T-type voltage-gated calcium channels (Cav3) that inhibits isoforms Cav3.1, Cav3.2 (IC50 = 0.54 μM), and Cav3.3 and decreases nifedipine-resistant phenylephrine-induced vasoconstriction in isolated mouse mesenteric arteries via Cav3.2 blockade when used at a concentration of 3 μM. In addition, it is a substrate of COX-1 and COX-2, as measured by oxygen consumption and product formation assays when used at a concentration of 50 μM. (±)5(6)-EET is provided as a mixture of the free acid and lactone.