Choose brands of fish oil in tryglyceride rather than ester form.

Triglyceride is the naturally structured oil as in the fish's body, ester is after distillation & altered. There are brands that reconvert esters to triglyceride form and this is ok.

In europe, triglyceride fish oil is the preferred type.

Ester form exists in some type of fish & spermeceti oil but is used for mechanical/industrial use, so u can imagine how tough this oil is. Absorption is a problem because ester type of oil is more for controlling buoyancy & protecting the skin. Triglyceride form is for the fish to consume for energy purposes.

To test if your fish oil is ester, pop the pill & pour onto a styrofoam/polystyrene material. U will notice it eats onto the foam & causes a hole in 10 minutes. Don't worry, this won't happen to your body. I've tried pristin & it ate thro the styrofoam within a few minutes.

ref
http://nzic.org.nz/ChemProcesses/animal/5E.pdf
http://www.nutraingredients.com/Research/F...-index-increase
http://www.examiner.com/nutrition-in-sacra...thyl-ester-form