How to Choose the Right Omega-3 Supplement?

A brief overview: What are omega-3 fatty acids?

Omega-3 fatty acids are well-studied for their supporting role in brain, heart, and immune health. While omega-3s are found in foods such as fatty fish, flaxseeds, walnuts, and certain fortified foods, dietary intake data suggest many people consume less than recommended levels. According to an analysis of National Health and Nutrition Examination Survey (NHANES) data, 68% of adults and 95% of children have intake below recommended levels.¹

To fill nutrient gaps, many people take omega-3 supplements, such as fish oil, krill oil, or algae oil. Let’s take a look at how different supplements stack up and what to consider when shopping for the best fish oil or other omega-3 supplement.

Omega-3 fatty acids are essential polyunsaturated fatty acids (PUFAs) that have to be acquired through food or supplements. Omega-3s integrate into cell membranes throughout your body, helping to support cellular function and brain, heart, and immune health.

There are three main forms of omega-3s: ALA, EPA, and DHA.

1. ALA is found in plant foods, such as flaxseeds and walnuts. On its own, this form can be used for certain important bodily functions, such as cellular energy production. It can also be converted into one of the other two more usable forms, but this process is inefficient².
2. Marine sources, on the other hand, provide EPA and DHA directly. When people talk about the benefits of omega-3s, they are usually referring to EPA and DHA.

EPA vs. DHA: What's the difference?

Omega-3 supplements often contain both EPA and DHA forms, each with distinct benefits.

EPA tends to circulate in the blood and supports a balanced, normal immune response and healthy circulation³. EPA has been extensively studied for cardiovascular health and vascular function, making it a popular choice for those looking for the best omega-3 for heart health⁴. EPA is also being studied for its ability to help support emotional well-being ⁵.

DHA has a more structural function. It concentrates in tissues, particularly in the brain and retina. As a building block, DHA helps maintain the membranes of brain cells to support normal cognitive health⁶.

Types of omega-3 supplements

There are three primary kinds of omega-3 supplements, each with its own advantages and potential trade-offs.

Fish oil

Fish oil is the most common omega-3 supplement. It’s typically extracted from cold-water marine species such as anchovies, sardines, mackerel, and salmon. Fish oil contains a high concentration of EPA and DHA and has been extensively studied. The primary drawbacks are its vulnerability to oxidation (which can reduce product quality if not properly processed and stored), potential for GI side effects (“fishy burps”), and ecological impact on fisheries. However, the best fish oil supplements address these concerns in various ways (more on this later).

Krill oil

Krill are small crustaceans living in the Antarctic Ocean. They store EPA and DHA in a different structure that some studies suggest may offer good bioavailability⁷. Krill oil also contains an antioxidant that helps protect it from oxidation. The primary trade-offs with krill oil are its higher cost, lower total concentration of EPA and DHA per softgel, and potential allergens for individuals with shellfish sensitivities.

Algae oil

Algae oil primarily comes from marine microalgae that are actually cultivated on land in highly controlled fermentation tanks. In nature, algae are the direct source of EPA and DHA for fish. Algae oil is bioavailable, sustainable, and vegan-friendly. While algae oil traditionally contained only DHA, modern strains deliver EPA as well. While algae oil won’t cause fishy burps and is free of possible ocean pollutants, it tends to be more expensive due to its manufacturing process.

What to look for in an omega-3 supplement

There are some common factors that everyone can consider when it comes to choosing an omega-3 supplement:

Active concentration vs. total oil volume

Many supplements advertise “1,200 mg fish oil” on the front label, but a closer look at the ingredients often reveals a much lower concentration of EPA and DHA. The rest are other naturally occurring fatty acids and lipids that may not share the same health benefits.

Molecular form: Triglyceride vs. Ethyl Ester

Fish oil comes in different forms depending on how it’s manufactured. Triglyceride (TG)—the natural form—and re-esterified Triglyceride (rTG) are well-absorbed⁸. The Ethyl Ester (EE) form has different bioavailability characteristics (absorption improves when taken with high-fat foods) and different stability properties than the TG form⁸. Each form has different properties that may affect product freshness and digestibility. If the label simply lists “fish oil concentrate” without specifying the molecular form, it’s most likely EE.

Third-party certifications

The best fish oil supplements take steps to ensure quality, safety, and sustainability. Look for seals such as NSF Certified for Sport®, which verify label accuracy and that the product has been tested for a range of contaminants and banned substances. Other certifications, such as Friend of the Sea® (FOS), ensure that the oil is sourced from highly regulated, sustainable fisheries. International Fish Oil Standards (IFOS™) is the leading third-party program for testing fish oils for omega-3 strength, contaminants, and freshness.

How much omega-3 do you need per day?

So, what is a good omega-3 supplement dosage? The US Department of Health and Human Services Dietary Guidelines for Americans recommend at least 8 ounces of seafood per week, or 250 to 500 mg of EPA and DHA daily, while the American Heart Association recommends two servings of oily fish per week, which would provide approximately 500 mg of EPA and DHA daily^9,10. When you’re comparing fish oil supplements, remember that you’re not looking for the overall amount of fish oil, but the specific amounts of EPA and DHA.

How AG Omega3 compares

AG Omega3 provides concentrated EPA and DHA omega-3 fatty acids to support healthy brain function, memory, cardiovascular health, and everyday immune resilience. It provides 1,125 mg of EPA and 875 mg of DHA in their naturally occurring triglyceride form for enhanced absorption and minimal GI discomfort or fish burps.

Sourced from high-quality, wild-caught fish, AG Omega3 is NSF Certified for Sport, International Fish Oil Standards (IFOS™) compliant, and Friend of the Sea certified—ensuring that our product is tested for contaminants and is sustainably sourced. Try AG Omega3 today.

References:

1. Murphy RA, Devarshi PP, Ekimura S, et al. Long-chain omega-3 fatty acid serum concentrations across life stages in the USA: an analysis of NHANES 2011-2012. BMJ Open. 2021;11(5):e043301. doi:10.1136/bmjopen-2020-043301
2. Brenna JT, Salem N Jr, Sinclair AJ, Cunnane SC. Alpha-linolenic acid supplementation and conversion to n-3 long-chain polyunsaturated fatty acids in humans. Prostaglandins Leukot Essent Fatty Acids. 2009;80(2-3):85-91. doi:10.1016/j.plefa.2009.01.004
3. Bodur M, Yilmaz B, Ağagündüz D, Ozogul Y. Immunomodulatory effects of omega-3 fatty acids: mechanistic insights and health implications. Mol Nutr Food Res. 2025;69(10):e202400752. doi:10.1002/mnfr.202400752
4. Yokoyama Y, Kuno T, Morita SX, et al. Eicosapentaenoic acid for cardiovascular…systematic review and network meta-analysis of randomized controlled trials. J Cardiol. 2022;80(5):416-422. doi:10.1016/j.jjcc.2022.07.008
5. Liao Y, Xie B, Zhang H, et al. Efficacy of omega-3 PUFAs…a meta-analysis. Transl Psychiatry. 2019;9(1):190. doi:10.1038/s41398-019-0515-5
6. Cardoso C, Afonso C, Bandarra NM. Dietary DHA and health: cognitive function ageing. Nutr Res Rev. 2016;29(2):281-294. doi:10.1017/S0954422416000184
7. Pham TPT, Cao PTN, Le TTD, et al. Comparison of omega-3 polyunsaturated fatty acids bioavailability in fish oil and krill oil: network meta-analyses. Food Chem X. 2024;24:101880. doi:10.1016/j.fochx.2024.101880
8. Dyerberg J, Madsen P, Møller JM, Aardestrup I, Schmidt EB. Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent Fatty Acids. 2010;83(3):137-141. doi:10.1016/j.plefa.2010.06.007
9. US Department of Agriculture, US Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th ed. December 2020. Accessed June 3, 2026. https://www.dietaryguidelines.gov/
10. Lee JH, O’Keefe JH, Lavie CJ, Marchioli R, Harris WS. Omega-3 fatty acids for cardioprotection. Mayo Clin Proc. 2008;83(3):324-332. doi:10.4065/83.3.324