Optimum Nutrition Fish Oil contain long-chain fatty acids, including docosahexaenoic acid (DHA) and eiscosapentaenoic acid (EPA). DHA and EPA are omega-3 fatty acids with important roles in numerous metabolic functions. They are found in foods like salmon and supplements such as ON Fish Oil Softgels. Our Fish Oil Softgels are mercury-free and enteric-coated, which means that you get all the benefits of fish oils without the fishy aftertaste that you might encounter without this special coating.