A long-chain polyunsaturated fatty acid derived from dietary alpha-linolenic acid. It contains twenty carbons, five double bonds, and is an omega-3 fatty acid. EPA can be made into PGE3, an anti-inflammatory substance that helps counter the effects of the inflammatory PGE2 substances. EPA is not found in the brain, but can be converted into DHA for use in the brain. EPA is important in the brain's blood supply.