Eicosapentaenoic acid (EPA) ethyl ester is an esterified form of the ω-3 fatty acid EPA . Dietary administration of EPA ethyl ester (41.4 g/100 g of total dietary fatty acids) increases the ex vivo activity of hepatic β-oxidation enzymes.^1,2 It also reduces total hepatic triglyceride levels and increases the ω-3 fatty acid content of hepatic triglycerides and phospholipids, as well as increases the total levels of ω-3 fatty acids in rats. EPA ethyl ester (1 g/kg) reverses increases in plasma cholesterol levels and reduces circulating triglyceride levels in rats fed a high-fat diet.³ Formulations containing eicosapentaenoic acid ethyl ester have been used as adjuncts in the treatment of hypertriglyceridemia.