all-cis-4,7,10,13,16,19-Docosahexaenoic acid methyl ester is a derivative of docosahexaenoic acid (DHA), an essential omega-3 fatty acid. It is primarily used as a reference standard and analytical reagent in laboratory settings for quality control and research. This compound serves as an intermediate in the synthesis of DHA-based products for pharmaceutical and nutraceutical applications, including dietary supplements that support cardiovascular health, brain function, and anti-inflammatory effects. It is also employed in biochemical studies to investigate omega-3 fatty acid roles in cellular processes, lipid metabolism, and disease prevention. Due to its high purity, it is suitable for developing analytical methods and as a starting material for functional foods and specialized formulations.