Essential Fatty Acids or EFAs are most commonly referred to as omega-3, omega-6, omega-9 fatty acids. Essential short chain polyunsaturated fatty acids come in two varieties. The Omega-3 variety is known as alpha-linoleic acid (ALA) and the omega-6 variety is called linoleic acid (LA). There are also essential long chain polyunsaturated fatty acids of the omega-3 and omega-6 families. The omega-3 varieties are known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The omega-6 varieties are known as gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA), and arachidonic acid (AA)
Research has shown that human metabolism requires both omega-3 and omega-6 fatty acids. Particular fatty acids are still needed at critical life stages (e.g. lactation) and in some disease states.