Fish oil is from natural and processed foods. Processing can change the form of fatty acids. Some forms are better absorbed than others. In fresh fish, free fatty acids, phospholipids, and triglycerides are present. Omega-3 fatty acids are available as triglycerides in fish oil. Ethyl esters from triglycerides are obtained from processed fish oil. It allows the adjustment of the concentrations of DHA and EPA. Reformed triglycerides are derived when the processed fish oils are reconverted into triglycerides. All forms have different health benefits.