On the basis of results of quantum-chemical researches with the analysis of atomic structure of molecule, it is shown that polyunsaturated omega-3 fatty acids have the expressed antioxidant and membranoprotective properties that with bioantioxidants karotenoids--tocopherols--are similar. At application in the sportsmen of medical drug Epadol on the basis of polyunsaturated omega-3 fatty acids it is shown that it brakes the activity of lipid peroxidation simultaneously, that is represented by reduction of maintenance of malonic dialdehyde as one of his eventual foods, and assists the improvement of antioxidant defence, that it contingently the increase of concentration of recovered glutathione in the membranes of red blood cells. Under the action of this medical drug the prooxidative-antioxidative coefficient for sportsmen goes down from 2.44 to 1.34 that specifies on a presence at Epadol of antioxidant properties. At the same time sorption ability of erithrocytes, characterizing functional properties of their membranes under act of Epadol goes down from 35.04 +/- 2.23% to 25.3 +/- 1.07% that counteracts to aggregating of red blood cells. An expediency of application of Ukrainian medical drug Epadol on the basis of polyunsaturated fatty acids in practice of preparation of sportsmen for normalization of structural and functional status of cell membranes as well as of prophylaxis noncontrolled apoptosis come into question.