This high purity omega-6 very long-chain fatty acid methyl ester is ideal as a standard and for biological studies. Dihomogamma- linolenic acid (DGLA) is an essential omega-6 polyunsaturated fatty acid that is strongly linked to anti-inflammatory and anti-cancer activities. DGLA is derived from gamma-linolenic acid (C18:3) and can be converted to arachidonic acid (AA, C20:4), a fatty acid associated with promoting inflammation. The lipid-peroxidizing enzyme cyclooxygenase (COX) is responsible for the conversion of DGLA to prostaglandin series 1 and 15-(S)- hydroxy-8,11,13-eicosatrienoic acid both of which have anti-inflammatory and anti-tumor properties.1 The conversion of DGLA to AA proceeds slowly due to the limited activity of the delta-5-desaturase enzyme; The subsequent accumulation of DGLA and its anti-inflammatory products attenuates AA metabolites such as prostaglandin series 2, 4-series leukotrienes and plateletactivating factor.2 Patients with atopic dermatitis have low DGLA levels in serum phospholipids and DGLA supplementation, rather than the more common gamma-linolenic acid, has been proposed as a treatment for this disease.3