Unfortunately, most fish oils available today have been over purified and/or insufficiently processed. Consequently, a hearty dose of the toxic waste materials, mercury, PCB's, dioxins, carcinogens and other undesirable elements, that we’re dumping into the sea find their way into the final product. Fish oil that hasn't been through processes like this are typically lower grade fish oils that are much weaker in strength and are very likely to contain potentially high levels of toxins.
Conventional fish oil manufacturers take a “purified” approach with their products. Because they often source many different types of fish stocks with varying levels of beneficial omegas, and ship these catches over long distances from countless fisheries before processing, they need to employ complex, high-heat purification processes, bleaching, deodorizing, fractionating, etc., to deliver an “acceptable” product. This extensive processing can break down the beneficial compounds in their fish oil. And while some manufacturers then attempt to “add back” specific vitamins or antioxidants, the benefits of the “whole” are lost forever.