A young woman chooses fish oil supplements at the store

The Secret of How to Choose the Best Fish Oil Supplement

Fish oil supplements are one of the most popular nutritional supplements taken by Americans today. That’s because fish oil is rich in essential omega 3 fatty acids, which your body needs for healthy functioning and cannot produce on its own. The only way to get these important nutrients is from your food or from supplements.

What is omega-3 good for? Omega 3s play an important role in healthy brain function1 and offer several well-researched omega-3 benefits for heart health, from lowering blood pressure and triglycerides to helping to keep your arteries clear.2 They also help reduce excess inflammation in the body, which is at the root of many chronic health conditions.3 These are just some of the incredible benefits that Omega-3 has to offer.

These well-researched benefits of omega 3s are associated with two fatty acids in particular: EPA and DHA. In our diet, EPA and DHA are found almost exclusively in fatty fish. The American Heart Association recommends eating fish at least twice a week to get those important omega 3 benefits, but many of us fall short of this threshold.

Some plants that we eat, such as flaxseed, walnuts, and soy, provide a different omega 3 fatty acid: ALA. But ALA is not the biologically active form of omega 3s for our bodies. Our bodies must convert ALA into active EPA and DHA to get the omega 3 benefits. Unfortunately, this conversion process is so inefficient, only about 10% of the ALA is usable as EPA or DHA.

Not only is the typical American diet low in omega 3s, it is excessively high in pro-inflammatory omega 6 fatty acids. A healthy omega 6 to omega 3 ratio is no more than 4:1, but the Western diet is more often between 10:1 and 50:1.4 Scientists believe that this imbalanced ratio contributes to excess inflammation in the body, a significant health risk factor.5

Most of us need to increase our intake of omega 3s to help restore balance to our diet and reduce excess inflammation. Omega-3 is consistently regarded as one of the nutrients we just don’t get enough of. If you don’t regularly eat fish, taking a quality fish oil supplement can help fill that nutritional gap. But it’s important to choose your fish oil supplement carefully. Fish oil supplements vary widely in quality, and not all of them are good for you.

Fish accumulate toxins from the ocean, so the oils must be carefully purified. Over-processing the oils may increase the risk of oxidation or change the structure of the fatty acids, making them less bioavailable. Fish oils are also prone to spoiling and must be well protected. A rancid oil will actually have negative effects on cholesterol6 and inflammation7, counteracting the very health benefits you’re seeking.

Finding a high quality fish oil supplement doesn’t have to be hard -- you just have to know what to look for. Check for these five things on the label to make sure you’re getting a quality fish oil supplement.

1. Check the Amount of EPA & DHA

It’s not the amount of fish oil in the capsule that counts, it’s the amount of omega 3 fatty acids. Most importantly, you want to check the amount of EPA and DHA. These are essentially the active ingredients that provide the omega 3 benefits you’re looking for.  

Check the supplement facts on the back of the label. Underneath the amount of fish oil, it should list the total amount of omega-3 fatty acids. This number should be close to the total amount of fish oil. That tells you that you are getting a potent, purified and distilled fish oil with a high omega 3 content.

Beneath the total omega 3s, the label should also list the amounts of EPA, DHA, and other omega 3s. The combined amounts of EPA and DHA should make up the majority of total omega 3s. If these amounts aren’t listed, be suspicious: you may not be getting the health benefits you’re paying for.

2. Check the Form of the Omega 3s

When we eat fish, we absorb EPA and DHA in the form of triglycerides. This is the natural form of omega 3s for our bodies and the easiest for us to metabolize. But during the oil refining process, these triglycerides are often converted into ethyl esters. Research shows that ethyl esters are not as well absorbed as triglycerides8, and may be more prone to oxidation.9

Most fish oil supplements on the market deliver their omega 3s in ethyl ester form -- but not all of them. If you’re not sure, check the supplement facts. The omega-3s should each be followed by a symbol that refers you to the very bottom of the label. There at the bottom, after the symbol, it should say “expressed as ethyl esters” or “expressed as triglycerides”. If it doesn’t say either way, it’s probably ethyl esters.

3. Check for Purification

All fish oils must be purified to remove heavy metals and other ocean pollutants, which can act as harmful neurotoxins. A high grade fish oil will use an advanced distillation technique such as molecular distillation, which uses low heat in a vacuum to carefully separate the omega 3s from other unwanted fatty acids and contaminants, resulting in a pure, concentrated omega 3 oil. 

Molecular distillation is generally considered the industry standard for quality processing, because it doesn’t require high heat that can damage the oil or create unhealthy trans fats. Most supplements that use molecular distillation will say so on the label. Some products also claim to be “pharmaceutical grade,” but this is not a real FDA term. It’s just a fancy marketing term for a high potency, molecularly distilled fish oil.

A fish oil supplement that’s molecularly distilled should be purified of any dangerous contaminants. The best quality supplement brands will confirm this with lab testing. Choose a reputable brand that submits their supplements to both in-house and third party testing to ensure purity. 

4. Check the Fish Source

If you shop for fish at the market, you’re probably already aware that some fish are cleaner, healthier, and more sustainably sourced than others. You probably avoid most farmed fish, which tend to live in less healthy conditions and may be exposed to antibiotics. Imported fish is also risky if the country doesn’t have strong regulations for seafood safety or sustainability.

The good news is that most fish that are naturally high in omega-3s are also some of the cleanest fish you can eat. This includes wild-caught salmon, cod, and pollock, as well as smaller fish like anchovies and sardines. A high quality fish oil supplement brand also shouldn’t be afraid to tell you where the fish was sourced from. Check the ingredients list to see if the fish and its source is listed.

The best fish come from clean, cold, and well-regulated waters, such as those off the coast of the U.S., Norway, and Iceland. In the U.S., Alaska is considered the gold standard source for fish, because it’s far from industrialized or highly populated areas, and regulated to protect against water pollution and overfishing. If you aren’t sure about the quality of the fish source, look for a seal of approval from a body such as the Marine Stewardship Council.

5. Check the Freshness

Fish oils are prone to oxidation, and once they start to spoil, they quickly lose their health value. While a good quality fish oil has antioxidant and anti-inflammatory benefits, an oxidized oil produces unhealthy byproducts that can have the opposite effect in the body. Rancid oils also have an unpleasant smell and taste, which may revisit you in the form of fishy burps.

Your fish oil supplement should include an antioxidant to help protect the oil from spoiling. Check the label for ingredients like vitamin E, vitamin C, or rosemary oil, as supplements with these ingredients are less likely to be spoiled. You should also check the expiration date; the older the supplement, the more likely it has started to oxidize.

The best freshness detector may be your own nose and taste buds. You shouldn’t taste or smell anything fishy (pun intended) when you swallow your supplement. You can also break open a capsule to make sure the oil doesn’t taste or smell like rotten fish. Keep your fish oil supplements fresh by storing them in the fridge or freezer, and using them up in a timely manner.

Our Naturelo Omega 3 Triglyceride Fish Oil supplement checks all the boxes for quality. It delivers 1100 mg of omega 3 fatty acids per softgel, including 729 mg of EPA and 275 mg of DHA, in the triglyceride form that your body prefers. Our fish oil is molecularly distilled and third party tested to ensure purity and potency. We source our fish oil from sustainable, wild-caught Alaskan pollock. And we include natural vitamin E (natural mixed tocopherols) in our supplement to help keep the oil fresh.

We also offer a vegan alternative to fish oil. Our Vegan DHA Omega 3 from Algae provides 800mg of DHA per softgel in the form of algal oil. Humans don’t normally eat algae, but fish do -- in fact, that’s how the fish get their omega 3s. Cutting out the “middle man” and getting DHA directly from algae avoids some of the toxicity and sustainability issues associated with fish. Algal oil is still vulnerable to oxidation, however, so we add rosemary oil to help keep it fresh.


1. Pearson, Keith. “How Omega-3 Fish Oil Affects Your Brain and Mental Health.” Healthline, Dec 2017.

2. Freuman, Tamara Duker. “How to Choose a Fish Oil Supplement.” U.S. News & World Report, Feb 2014.

3. Calder, Philip C. “Omega-3 fatty acids and inflammatory processes.” Nutrients vol. 2,3 (2010): 355-74. doi:10.3390/nu2030355

4. Robertson, Ruairi. “Omega 3-6-9 Fatty Acids: A Complete Overview.” Healthline, Jan 2017.

5. Gunnars, Kris. “How to Optimize Your Omega-6 to Omega-3 Ratio.” Healthline, June 2018.

6. García-Hernández VM, Gallar M, Sánchez-Soriano J, Micol V, Roche E, García-García E. “Effect of omega-3 dietary supplements with different oxidation levels in the lipidic profile of women: a randomized controlled trial.Int J Food Sci Nutr. 2013;64(8):993-1000. doi:10.3109/09637486.2013.812619

7. Wang, W., Yang, H., Johnson, D., Gensler, C., Decker, E., and Zhang, G. (2017). “Chemistry and Biology of -3 PUFA Peroxidation-Derived Compounds, Prostaglandins Other Lipid Mediators.” (2016). Prostaglandins & Other Lipid Mediators, 132: 84 – 91.

8. Neubronner J, Schuchardt JP, Kressel G, Merkel M, von Schacky C, Hahn A. “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;65(2):247-254.

9. Sullivan Ritter, J.C., Budge, S.M., Jovica, F. et al.Oxidation Rates of Triacylglycerol and Ethyl Ester Fish Oils.” J Am Oil Chem Soc 92, 561–569 (2015). https://doi.org/10.1007/s11746-015-2612-9