The Truth About Prescription Fish Oil

by Mike Roussell

Is prescription fish oil any better than your favorite fish oil supplement?

In The Beginning…

In the early days, fish oil supplementation was crude. You couldn’t get the high doses needed without suffering the unwelcoming side effects: fishy taste, heartburn, diarrhea, and fish farts. (1)

The purification process for fish oil supplements began to advance as the demand for high-quality products grew. Today you can easily get your hands on the good stuff, but sadly, the shelves of your local discount retailer are still lined with fish oils containing impurities.

Enter Big Pharma

Reliant Pharmaceuticals saw the need for “pharmaceutical grade” fish oil and began to devise a way to make a fish oil product that was +80% EPA/DHA compared to the 30% EPA/DHA that you’d find at the discount retailer. (2, 3) They were able to achieve this through a patented purification process, which housed EPA and DHA as ethyl esters instead of triglycerides.

Now, the triglyceride form is how EPA and DHA are normally found, with three fatty acids connected by a common “backbone.”

In Big Pharma’s ethyl ester form, EPA and DHA exist individually and not in the naturally occurring triglyceride structure.

Omega-3 ethyl esters were studied extensively, with the largest study containing over 18,000 subjects. (4) As a result of that study, the FDA approved omega-3 ethyl esters for the treatment of high triglycerides.

Thus, the first prescription fish oil supplement was born under the name Omacor. Today it’s called Lovaza.

$200 Fish Oil Anyone?

While scientists worked on developing omega-3 ethyl esters, other scientists were optimizing molecular distillation techniques that allowed for 60% EPA/DHA purity – double the discount store’s variety.

Despite the different chemical make-up of omega-3 ethyl esters and natural fish oil supplements, I’ve never heard a researcher refer to omega-3 ethyl esters as being superior to fish oil.

Are they? Does your body process the omega-3 ethyl esters differently than it would if you ate a piece of salmon or took some Flameout? If so, do these differences warrant an omega-3 ethyl ester price tag upwards of $200 a month?

Comparing Purity

The higher percentage of EPA/DHA in your supplement, the less room there is for other fats, and more notably, the less room there is for chemical impurities like dioxins.

Molecularly-distilled fish oil products, like Flameout, have impurities removed. The World Health Organization’s standard for dioxins is less than two parts per million.

A molecularly-distilled fish oil product can contain as little as 0.3 parts per million dioxins. Would the 85% pure omega-3 ethyl ester product contain less? Probably. Is this difference going to impact your health? Probably not.

Comparing Effectiveness

So from a contamination standpoint, molecularly-distilled fish oil supplements and omega-3 ethyl esters stack up about the same. How does your body treat them? Up until this year there wasn’t that much research to answer this question.

Two studies now point to a difference in bioavailability.

The first study, published in the journal of Prostaglandins, Leukotrienes and Essential Fatty Acids (or what I like to call “light bedtime reading”) examined the bioavailability differences between fish oil supplements, including omega-3 ethyl esters. (3)

Researchers found the bioavailability of the omega-3 ethyl esters was -27% compared to the control fish oil (which was basically the equivalent of squeezing the EPA and DHA out of a salmon filet).

The difference wasn’t statistically significant, although omega-3 ethyl esters were consistently worse performers in the different tests. Still, the findings didn’t support omega-3 ethyl esters as being a superior product.

The European Journal of Clinical Nutrition published a study last month with twice as many subjects as the first one. (5) During the six-month time span, researchers gave subjects either a high-quality fish oil supplement – in the naturally occurring triglyceride form – or an omega-3 ethyl ester.

Researchers even measured subjects’ omega-3 index to find the amount of EPA and DHA in red blood cell membranes. This is the best way to measure omega-3s in the body, because when EPA and DHA are in your red blood cell membranes they’re locked and loaded, just waiting to be clipped off by the right enzyme and put to use.

The researchers found at months three and six that those receiving the high-quality triglyceride fish oil supplement had a much higher omega-3 index at both time points. Sorry, ethyl esters.

The Winning Option

Just because a product requires a prescription doesn’t mean it’s better or more effective.

Highly-purified, molecularly distilled fish oil supplements like Flameout (Buy at Amazon) provide a safe and potentially more effective alternative to prescription omega-3s.

Flameout Buy-on-Amazon



  1. Belluzzi A et al. Effect of an Enteric-Coated Fish-Oil Preparation on Relapses in Crohn’s Disease. N Engl J Med. 1996 Jun 13;334(24):1557-60. PubMed.
  2. Bays H. Clinical overview of Omacor: a concentrated formulation of omega-3 polyunsaturated fatty acids. Am J Cardiol. 2006;98:71i-76i. PubMed.
  3. Dyerberg J et al. Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent Fatty Acids. 2010 Sep;83(3):137-41. PubMed.
  4. Valagussa F et al. Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Lancet. 1999;354(9177):447-455.
  5. Neubronner J et al. Enhanced increase of omega-3 index in response to long-term n-3 fatty acid supplementation from triacylglycerides versus ethyl esters. Eur J Clin Nutr. 2011 Feb;65(2):247-54. PubMed.