Fish Oil vs Krill Oil: Which Is Better? (2026)
Reviewed by the RovunoReviews Research Team · Reviewed against our Review Methodology · Updated September 2026
This article is for informational purposes only and is not medical advice. Individual results vary, and you should consult a healthcare professional before starting any new supplement, especially if you are pregnant, nursing, or taking other medications, or have a shellfish allergy.
Quick Verdict: It depends on your budget versus your tolerance for fishy burps. Fish oil is cheaper and delivers a higher EPA/DHA dose per capsule, making it the more cost-effective choice for most people. Krill oil is more expensive per gram of omega-3 but is bound to phospholipids, which some research suggests improves absorption, and it causes less “fish burp” for people sensitive to it, plus it naturally contains the antioxidant astaxanthin.
Overview
Fish oil and krill oil are both omega-3 supplements, but they come from very different sources and deliver their omega-3s in different molecular forms. Fish oil is extracted from oily fish and delivers EPA and DHA in triglyceride or ethyl ester form. Krill oil comes from tiny Antarctic crustaceans and delivers omega-3s primarily as phospholipids, the same form omega-3s take in your cell membranes, which is the basis for claims that krill oil absorbs better.
What Is Fish Oil?
Fish oil is a widely available, well-studied omega-3 supplement extracted from oily fish like anchovies, sardines, and salmon, standardized to a specific EPA/DHA content per serving.
- Best for: getting the most EPA/DHA per dollar
- Best for: higher total daily omega-3 doses
- Best for: people without a shellfish allergy concern
- Best for: long-term daily cardiovascular support on a budget
Typical dose: 250mg–2g combined EPA/DHA daily. Common side effects include fishy aftertaste and burping; high doses can modestly increase bleeding risk.
What Is Krill Oil?
Krill oil is extracted from small shrimp-like crustaceans (krill) harvested mainly from Antarctic waters, delivering omega-3s bound to phospholipids along with the antioxidant astaxanthin, which gives krill oil its reddish color.
- Best for: people bothered by fish-oil burp-back
- Best for: those who prioritize absorption form over raw dose
- Best for: getting a small amount of astaxanthin alongside omega-3s
- Best for: people willing to pay more per gram of omega-3
Typical dose: 500mg–1g of krill oil daily (delivering roughly 100-300mg combined EPA/DHA, notably less per capsule than fish oil). Side effects are generally similar to fish oil, but krill oil is derived from shellfish and is not appropriate for people with shellfish allergies.
Evidence & Effectiveness Scores
Head-to-Head Comparison
| Category | Fish Oil | Krill Oil |
|---|---|---|
| Omega-3 Form | Triglyceride / ethyl ester | Phospholipid-bound |
| EPA/DHA per Serving | Higher | Lower |
| Extra Nutrient | None notable | Astaxanthin (antioxidant) |
| Allergy Consideration | Fish allergy | Shellfish allergy |
| Typical Price | $ | $$$ |
| Fishy Burp-Back | More common | Less common |
Best Uses for Each
✅ FISH OIL: BEST FOR
- Budget-conscious daily supplementation
- Higher total omega-3 dose needs
- People without a shellfish allergy concern
- Straightforward, well-studied dosing
✅ KRILL OIL: BEST FOR
- People who get fishy burps from fish oil
- Those prioritizing absorption efficiency
- Wanting a bit of astaxanthin alongside omega-3s
- Smaller, lower-dose daily capsules
Who Should Choose Fish Oil?
Fish oil is the better pick for most people who want the most omega-3 per dollar and don’t have a specific sensitivity to it. It remains the most cost-effective, best-studied option for daily EPA/DHA supplementation.
Who Should Choose Krill Oil?
Krill oil is worth the premium if you’ve tried fish oil and found the burp-back intolerable, or if you specifically want the phospholipid-bound absorption profile and don’t mind a smaller total omega-3 dose per capsule and higher cost.
Can You Take Both?
There’s no specific danger in taking both, but there’s also little practical reason to. They supply the same core nutrients (EPA and DHA) in different delivery forms, so combining them mostly just adds cost without a clear added benefit over choosing one at an adequate dose. Pick one based on your budget and GI tolerance rather than stacking them.
Frequently Asked Questions
Is krill oil really better absorbed than fish oil?
Some studies suggest the phospholipid form in krill oil may be absorbed somewhat more efficiently per milligram than the triglyceride/ethyl ester forms in most fish oil, but the differences are modest, and fish oil’s higher total EPA/DHA dose per capsule often outweighs a small per-milligram absorption edge in practice.
Can I take krill oil if I have a shellfish allergy?
No, krill are crustaceans, and krill oil is not appropriate for people with shellfish allergies. Choose fish oil instead, and check with a doctor if you have any seafood allergy history.
Which one is better for heart health specifically?
Fish oil has a much larger and longer-running body of cardiovascular research behind it, simply because it’s been studied for decades longer and at higher doses than krill oil.
Does astaxanthin in krill oil do anything meaningful?
Astaxanthin is a genuine antioxidant with its own research base, but the amount present in a typical krill oil serving is quite small compared to dedicated astaxanthin supplements, so don’t expect krill oil to double as a significant astaxanthin source.
The Bottom Line: Fish oil wins on value, krill oil wins on tolerance. If cost and total EPA/DHA dose matter most to you, fish oil is the more efficient choice. If you’ve struggled with fish-oil burps or want the phospholipid-bound form, krill oil is a reasonable (if pricier) alternative, just budget for the lower dose per capsule.
These statements have not been evaluated by the Food and Drug Administration. This content is not intended to diagnose, treat, cure, or prevent any disease and is not a substitute for advice from your doctor or pharmacist.