Background. Omega-3 polyunsaturated fatty acids (ω3-PUFA) are an important factor in somatic and reproductive health. Micronutrient and pharmaceutical preparations based on ω3-PUFA are widely used for cardioprotection (prevention of atherosclerosis, endothelial dysfunction, chronic inflammation, and excessive thrombosis), support of reproductive function during pregnancy and improvement of neurological development in children. The effectiveness of ω3-PUFA preparations is determined by their fatty acid composition: the amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and other types of unsaturated and saturated fatty acids.Objective: To analyze the fatty acid composition of micronutrient and pharmaceutical ω3-PUFA preparations.Material and methods. The fatty acid composition of 16 ω3-PUFA preparations was analyzed. A quantitative chromatographic method was used to determine more than 50 fatty acids, their derivatives, and other compounds.Results. Previously identified pharmacomarkers of fatty acid composition were confirmed, and new ones were obtained, that allow for highly reliable differentiation between highly standardized ω3-PUFA preparations (such as Omacor®, NFO® Omega-3 Premium, NFO® Omega-3 Strong DHA, NFO® Omega-3 Ultima, etc.) and less standardized products (Fish oil-Teva®, Omeganol®, etc.). New, more effective criteria for assessing the quality of the fatty acid composition of ω3-PUFA preparations were proposed. In particular, compliance with the criteria “ω11<3%” and “EPA+DHA>55%” corresponds to more standardized preparations with better purification quality. The usefulness of our proposed standardization coefficient for evaluating the conformity of measured ω3-PUFA levels to the amounts claimed by manufacturers was confirmed.Conclusion. Compliance with the criteria “ω11<3%” and “EPA+DHA>55%” corresponds to more standardized preparations. The identification of highly standardized compositions allows physicians and patients to make informed choices when selecting ω3-PUFA products.