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August 01, 2025

Krill Oil vs. Fish Oil: Which Omega-3 Supplement Is Better?

Krill oil and fish oil are both rich in omega-3s—but they differ in potency, cost, and effectiveness. Discover why fish oil remains the top choice for optimizing EPA and DHA levels. Learn how to choose the best supplement for your health and your wallet.

krill oil vs Omega-3 fish oil

Krill Oil vs. Fish Oil: What’s the Difference, and Which One Is Better for Omega-3s?

Omega-3 fatty acids are essential to human health, with well-established benefits for cardiovascular function, brain performance, inflammation control, metabolic health, and more. But when it comes to supplementing these vital fats, a common question arises: Should you choose krill oil or standard fish oil?

In this comprehensive guide, we’ll explore the key differences between krill oil and fish oil, including their composition, absorption, sustainability, clinical effectiveness, and cost efficiency—especially in relation to optimizing omega-3 levels. We’ll also explain why krill oil often falls short in both dose and price compared to high-quality, standard fish oil supplements.

What Are Omega-3 Fatty Acids and Why Do They Matter?

Omega-3s are a group of essential polyunsaturated fats. The two most critical omega-3s for human health are:

  • EPA (eicosapentaenoic acid): Supports heart health, immune function, mood, and inflammation control.

  • DHA (docosahexaenoic acid): Essential for brain function, vision, and fetal development.

These fatty acids are not produced efficiently by the body, meaning we must obtain them from diet or supplements. Cold-water fatty fish like salmon, sardines, and anchovies are excellent sources—but most people don’t eat enough seafood weekly to meet their needs.

As a result, fish oil supplements have become a convenient and effective way to increase EPA and DHA intake. In recent years, krill oil has gained popularity as an alternative—but is it truly better?

Krill Oil vs. Fish Oil: An Overview

Feature Fish Oil Krill Oil
Source Fatty fish (e.g., anchovies, sardines) Antarctic krill (tiny crustaceans)
Main Omega-3 Forms Triglycerides or ethyl esters Phospholipids
EPA/DHA Content (per gram) ~180mg EPA, ~120mg DHA (varies) Much lower: often <60mg EPA and <30mg DHA
Other Nutrients Vitamin A & D (in cod liver oil), minimal antioxidants Contains astaxanthin (antioxidant)
Bioavailability High in triglyceride form, moderate in ethyl ester form Potentially better absorption due to phospholipid structure
Capsules per Dose Usually 1–2 Often 2–6 to match fish oil EPA/DHA
Cost per Serving Affordable ($0.20–$0.50 daily) Expensive ($1.00–$2.00 daily or more)
Sustainability Varies by source; MSC-certified available Generally more sustainable—but extraction has growing impact

1. Omega-3 Content: Fish Oil Wins by a Wide Margin

Perhaps the most important metric in this comparison is how much EPA and DHA you actually get per serving.

  • Standard fish oil provides about 300–600mg of EPA+DHA per softgel depending on concentration.

  • Krill oil, by contrast, often contains less than 100mg EPA+DHA per capsule.

This means you'd need to take 4–6 krill oil capsules daily just to match the omega-3 content of 1–2 standard fish oil capsules.

That’s a significant disadvantage, especially for anyone aiming to optimize omega-3 levels for therapeutic benefit.

2. Absorption and Bioavailability: A Slight Edge for Krill, But Not Enough

Krill oil contains omega-3s bound to phospholipids, while standard fish oil is usually in the triglyceride or ethyl ester form.

What does this mean?

  • Phospholipids may improve absorption, especially in people with impaired digestion or gallbladder issues.

  • However, recent studies show no clinically meaningful difference in blood omega-3 levels between high-quality triglyceride fish oil and krill oil, when EPA/DHA intake is matched.

Bottom line: Any absorption advantage is minor and doesn’t compensate for the much lower EPA/DHA dose in krill oil products.

3. Clinical Evidence: Fish Oil Is Better Studied and Proven

Fish oil has been the subject of thousands of studies examining its effects on:

  • Cardiovascular health (blood pressure, triglycerides, heart rhythm)

  • Brain function and cognition

  • Inflammation and joint pain

  • Prenatal development

  • Eye and skin health

Krill oil research, by comparison, is limited and relatively new. While some small trials suggest benefit, it has nowhere near the volume or consistency of data backing fish oil’s therapeutic effects.

In fact, most krill oil studies show modest results, often due to lower EPA/DHA doses used compared to fish oil research.

4. Cost Comparison: Krill Oil Is Far Less Cost-Effective

Let’s break down the math:

  • A high-quality omega-3 fish oil supplement may provide 1,000mg of EPA+DHA per capsule and cost $0.40–$0.60 per dose.

  • A standard krill oil supplement may provide only 100–200mg of EPA+DHA per 2 softgels and cost $1.00–$2.00 per day for an effective dose.

To match a therapeutic intake of 2,000–3,000mg EPA+DHA/day, you might need:

  • 2–3 capsules of concentrated fish oil ($0.80–$1.20 total)

  • 6–12 capsules of krill oil, which could cost $3.00–$6.00/day

In short: krill oil is 3–5x more expensive than high-quality fish oil for the same dose of active omega-3s.

5. Sustainability: Krill Oil Has an Edge—But at a Price

Krill oil is often marketed as more environmentally sustainable than fish oil because Antarctic krill are abundant and low on the food chain.

However, concerns are rising about overharvesting krill, which are a key food source for whales, seals, and penguins. As demand for krill oil grows, so does the risk to fragile marine ecosystems.

Meanwhile, fish oil brands certified by the Marine Stewardship Council (MSC) or Friend of the Sea are sustainably sourced from small, fast-reproducing fish like anchovies and sardines.

Takeaway: Both can be sustainable—just choose reputable brands. Krill isn’t automatically better for the planet.

6. Astaxanthin in Krill Oil: Beneficial but Not Unique

Krill oil naturally contains astaxanthin, a potent antioxidant that gives it its red color. Astaxanthin has been linked to benefits for:

  • Eye and skin health

  • Exercise performance

  • Brain and cardiovascular protection

However, astaxanthin is also available as a standalone supplement, often at a much higher dose than what's found in krill oil (which typically contains only 0.5–2mg per serving).

If you want astaxanthin, it’s better to supplement it separately and strategically—rather than relying on a low dose in an already expensive omega-3 product.

7. Capsule Size, Taste, and Digestibility

  • Krill oil capsules are often smaller and easier to swallow.

  • They’re also less likely to cause the classic “fish burps” or indigestion.

  • That said, modern enteric-coated or triglyceride-form fish oil also minimizes burping and improves digestibility.

If you’ve had bad experiences with older fish oil products, a switch to a higher-quality formula (with citrus oil or rosemary extract) typically resolves the issue—without the high cost of krill oil.

8. When Might Krill Oil Be Worth Considering?

Despite its disadvantages, krill oil may be worth considering for:

  • People with digestive issues who tolerate krill oil better than fish oil

  • Those who prefer smaller capsules

  • Individuals specifically seeking a low-dose antioxidant + omega-3 combo

  • People with mild omega-3 needs who prioritize convenience over cost

However, for the vast majority of people—especially those targeting therapeutic omega-3 levels—krill oil is simply not cost-effective.

9. How to Choose a Quality Fish Oil Supplement

To get the most out of your omega-3 supplement, look for:

  • High EPA and DHA content: Aim for at least 500–1,000mg EPA+DHA per capsule.

  • Triglyceride form: Better absorbed than ethyl esters.

  • IFOS or GOED certification: Guarantees purity, potency, and low oxidation.

  • Third-party testing: Ensures no heavy metals, PCBs, or rancidity.

  • Freshness date: Choose products with good shelf life and no fishy odor.

At Revolution Health, we recommend Omega 1300, our physician-formulated, high-potency fish oil supplement that delivers 1,300mg of pure omega-3s per serving, with an emphasis on EPA for cardiovascular and metabolic health. It’s clean, effective, and cost-efficient.

Explore Omega 1300 here →

10. Verdict: Krill Oil or Fish Oil—Which Is Better?

Criteria Winner
Omega-3 dose per capsule Fish Oil
Absorption Slight edge to Krill
Clinical research Fish Oil
Sustainability Tie (depending on brand)
Cost per effective dose Fish Oil
Convenience for therapeutic levels Fish Oil

Final Conclusion:

Fish oil is the clear winner for most people—especially those aiming to improve or maintain healthy omega-3 levels efficiently and affordably.

While krill oil has some unique qualities, the low EPA/DHA content and high price point make it a poor choice for achieving meaningful blood levels of omega-3s without taking large numbers of capsules daily.

If your goal is to support heart health, reduce inflammation, or optimize metabolic function, a high-quality, concentrated fish oil supplement will give you far more benefit per dollar—and per capsule.

References

  1. Nichols PD, et al. Omega-3 oils: Sources, health effects, and future directions. Nutrients. 2021.

  2. Saldeen T, et al. Absorption of EPA and DHA from krill oil vs fish oil: What does the science say? Lipids Health Dis. 2020.

  3. Maki KC, et al. Krill oil vs. fish oil: A randomized, crossover trial. Nutrition Research. 2009.

  4. European Food Safety Authority (EFSA). Opinion on the safety and efficacy of krill oil for human consumption. EFSA Journal. 2012.

  5. GOED. Omega-3 Supplementation Guidelines.

  6. Marine Stewardship Council (MSC). Sustainable sourcing of marine omega-3s.

  7. International Fish Oil Standards (IFOS) Program. Product Quality Reports.