The omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid are long-chain n-3 polyunsaturated fatty acids, which compete with arachidonic acid for inclusion in cyclo-oxygenase and lipoxygenase pathways. Their actions include hypolipidaemic action (especially a reduction in plasma triglycerides) by reducing very-low-density lipoproteins; anti-inflammatory action, attributed to effects on leukotriene synthesis; and antiplatelet effect, attributed to effects on prostanoid synthesis, which promote vasodilatation, reduction in platelet aggregation, increased bleeding time and decreased platelet counts.