The rate of death related to haemostatic impairments such as arterial and venous thrombosis, heart attacks, strokes, and peripheral vascular diseases has reached the rates of death caused by cancer formations in the last decade. Fish oils are very rich of ω–3 fatty acids and they are a promising alternative for prevention and treatment of such kind of illness. Recently a lot of scientific groups in all over the world focused on investigation of composition and physiological properties of fish oils. Presently, this kind of food additives are not yet classified as medical drugs and they are not subject of strict control. But the dynamics of the European Union and its legal system could rapidly redefine this kind of supplements to medicinal drugs and to impose their strict and binding control.

Herein, we report our investigation on analyzing and defining the content of ω-3 fatty acids in dietary supplements containing extracts of fish oils commercially available in Europe. Additionally, we will discuss the methods used for sample preparation and methodology used for GC-MS determination.