Re-esterified triglyceride (rTG) fish oil is a more natural form of omega-3 fatty acid using the re-esterification process. Re-esterification is a process that removes the artificially induced alcohol in chemically modified ethyl ester fish oil to create a more natural form. This helps reduce the gastrointestinal side effects as well as help the absorption of omega-3 fatty acids compared to its other ethyl ester form.