The Natural Fish Oil Concentrate used in this softgel is manufactured under strict quality control standards. It is screened for the absence of potentially harmful levels of contaminants (i.e. mercury, heavy metals, PCB’s, dioxins, and other contaminants). This Fish Oil Concentrate is primarily derived from sardines, anchovies and mackerel. From the FDA’s website: “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 (see nutrition information for fat content)”.