Arachidonic acid is a long-chain fatty acid that is a C20, polyunsaturated fatty acid having four (Z)-double bonds at positions 5, 8, 11 and 14. It has a role as a human metabolite, an EC 3.1.1.1 (carboxylesterase) inhibitor, a Daphnia galeata metabolite and a mouse metabolite. It is an icosa-5,8,11,14-tetraenoic acid, an omega-6 fatty acid and a long-chain fatty acid. It is a conjugate acid of an arachidonate. It derives from a hydride of a (5Z,8Z,11Z,14Z)-icosa-5,8,11,14-tetraene.