From an economic standpoint, the fish oil companies find it profitable to use inedible, trash fish that would otherwise not be found in restaurants, grocery stores or homes.  Again from an economical standpoint, in order to capture all the oil from the fish found in the body, the fish are boiled to approximately 300 degrees, and then pressed to extract more oil which again generates tremendous heat from the friction of pressing.  Now all the oil can be extracted from the fish but, because of the methods used to extract the oil, the oil is burned, scorched and inedible, so to purify the oil at this point, the oil goes through a molecular distillation process.  Here the oil is purified and the levels of EPA and DHA are either spiked or artificially manipulated with urea and soda ash to a level that suits the manufacturer.  All fish oils do not have the same ratio of EPA and DHA on its molecular structure as it is found in fish.  Fish oil is highly processed and refined just as the cheap vegetable oils found in the supermarket.  EPA and DHA occur in fish at a very low level.  The multiple grams of fish oil that are recommended are due to its poor absorption and restructuring of its molecular components.  In many cases fish oil is highly contaminated with PCBs and heavy metals.  It is impossible to make fish oil fresh, clean, and free of contaminants.  The absolute best way to get fish oil is from eating fish, especially sardines, herring and salmon.  There is an alternative which is a very special phospholipid complex extracted from the head of salmon which contains five natural phospholipids, EPA and DHA, and peptides (proteins) to support heart, brain and eye health.  The French government spent many years, after enlisting the three top lipid researchers in France, to locate this very valuable phospholipid complex.  Just one tablet daily of this unique phospholipid complex containing omega-3 fatty acids from salmon.  Just one small tablet daily – no burping, no regurgitation.