The natural fish oil concentrate used in this softgel is manufactured under strict quality control standards. It is tested to be free of potentially harmful levels of contaminants (i.e. mercury, heavy metals, PCB's, dioxins, and other contaminants). Those who experience nausea or reflux from other fish oils should find this enteric coated, odor controlled softgel easier to digest. Consumption of Omega-3 fatty acids may reduce the risk of coronary heart disease. FDA evaluated the data and determined that although there is scientific evidence supporting the claim, the evidence is not conclusive.