About Fish Oil Forms: Which is Superior?

Q: How many different fish oil forms are there, and what is the difference?

A: Fish oils are available in three forms:

  • Natural Triglyceride (TG): Fish naturally contain the omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) as triglyceride esters. Natural TG fish oils provide a maximum of 300 mg of combined EPA and DHA per 1,000 mg of oil (30% potency). These are the most common fish oils on the market, and some prefer them because of their natural form and close similarity to eating fish.
  • Ethyl Ester (EE): Since EPA and DHA concentration and ratio can't be altered in natural TG fish oil, the EE fish oil form was created. By removing the glycerol backbone of TG fish oil, in a process called trans-esterification, the result is FFAs (free fatty acids) and a free glycerol molecule. An ethanol molecule is attached to each of the FFAs, creating EE. The resulting EE allows for molecular distillation at lower temperatures, creating EPA and DHA concentration levels greater than naturally found in fish. This form is called "fish oil concentrate."
  • Re-Esterified Triglyceride (rTG): rTGs are created when ethyl esters are freed from their attached ethanol groups and are once again bound to a glycerol backbone. rTGs retain the same potency and fatty acid ratios of their EE counterparts.

Q: Are Carlson fish oils in TG or EE form?
While there are three forms of marine oils, Carlson fish oils fall into four categories:

  1. Non-concentrated 100% natural triglycerides (TG)
  2. Concentrated ethyl esters (EE)
  3. Concentrated re-esterified triglycerides (rTG)
  4. A mixture of both the natural TG form and the more potent EE

Q: Is one form better than the other?
No. Whether you choose TG, EE, or rTG fish oil, what's most important is the end result. Omega-3 supplements from fish oil are lifestyle supplements meant to be taken long-term for the benefits associated with an EPA and DHA red blood cell concentration above 8%. An appropriate daily dose of any form can achieve this goal and help maintain optimal blood EPA and DHA levels.