Natural Factors pure Wild Alaskan Salmon Oil is a good source of Omega-3 fatty acids with the same ratio found in free-swimming salmon. Many studies show that Omega-3 fatty acids found in fish oil have numerous health advantages and are especially helpful for the cardiovascular system.* This oil is extracted from already harvested salmon using fish parts that would otherwise be wasted, therefore there is no depletion of existing stocks. Natural Factors Wild Salmon Oil has no antibiotic or hormone residues often found in farmed salmon and is frequently tested for chemical residues and heavy metals.