Lipids & Fatty Acids

Krill Oil

Also known as: Antarctic krill oil, Euphausia superba oil, Krill oil capsules

Omega-3s in phospholipid form — better absorbed than fish oil per gram, with astaxanthin and a smaller dose requirement.

By IngredientWiki Editorial Team
Fact-checked by IngredientWiki Editorial Team
Updated 2026-09-26
2 min read

In short

Krill oil is extracted from Antarctic krill, tiny shrimp-like crustaceans that form the largest animal biomass on earth, and its defining feature is packaging: its omega-3s (EPA and DHA) ride on phospholipids — the same structures as human cell membranes — rather than the triglycerides of fish oil. That difference translates into better absorption, meaning lower gram doses achieve comparable blood levels, and krill oil arrives with natural astaxanthin, a potent antioxidant. Trials show effects comparable to fish oil for lipids and cardiovascular markers at roughly two-thirds the omega-3 dose. The trade-offs: higher price and limited environmental oversight.

Omega-3s bound to phospholipids — cell-membrane-like delivery
Better absorption than fish oil per gram of omega-3
Contains natural astaxanthin (the red antioxidant)
Comparable lipid effects at ~2/3 the fish-oil dose

What is Krill Oil?

Krill oil is the omega-3 category's delivery-system argument: the same EPA and DHA found in fish oil, but carried on phospholipids — the molecular architecture of cell membranes themselves — which makes the fats more water-friendly and measurably better absorbed. The practical consequences follow: lower pill counts, no fishy burps (the oil emulsifies readily), and a built-in bonus of astaxanthin. The clinical literature has largely confirmed the equivalence story — krill oil moves blood lipids and cardiovascular markers like fish oil, at roughly two-thirds the omega-3 dose — while the price premium and sustainability questions define the honest trade-offs.

Where it comes from

Natural sources

Extracted from Euphausia superba, Antarctic krill — the ocean's most abundant animal
Omega-3s (EPA/DHA) are bound to phospholipids rather than triglycerides
Naturally contains astaxanthin, the red antioxidant pigment

How it's made

Sold as oil in softgels (typically 500 mg–1 g each), often with phospholipid content listed.

What it does in products

Benefits

Omega-3 delivery

strong evidence

Absorption studies show krill-oil omega-3s achieve comparable blood levels to fish oil at lower doses — the phospholipid advantage, well documented.

Lipids and cardiovascular markers

moderate evidence

Trials find krill oil improves triglycerides and some inflammatory markers, comparable to fish oil at roughly two-thirds the omega-3 dose.

Joint comfort

emerging evidence

A few trials report reduced knee-pain scores and inflammatory markers; promising but smaller than the lipid literature.

Side effects & safety

Fishy aftertaste (uncommon)Less common than fish oil — the emulsifying phospholipids reduce reflux-and-burp issues.

Stomach upset (uncommon)Usually mild; take with food.

Safety considerations

Generally considered acceptable in pregnancy (omega-3s are recommended), but confirm with your provider.
Adds to anticoagulant effects — caution with blood thinners.
Not for: Shellfish allergy (krill are crustaceans)
Not for: Scheduled surgery (stop 2 weeks prior)

How it's used

In supplements

Typical: 1–3 g of krill oil daily (providing 250–500 mg combined EPA/DHA), with meals. Effects on lipids build over 8–12 weeks.

Regulatory status

Dietary supplement under DSHEA; no drug approval. Krill fisheries operate under CCAMLR management with certification programs (MSC).
GRAS (generally recognized as safe) for food use.

Phospholipids vs triglycerides: the absorption argument, tested

The krill-oil pitch rests on a chemical difference worth understanding: fish-oil omega-3s float as triglycerides — oil droplets that need bile and pancreatic processing before absorption — while krill-oil omega-3s arrive pre-integrated into phospholipids, the water-compatible molecules of cell membranes. Absorption studies confirm the consequence: blood omega-3 levels rise comparably from smaller krill-oil doses, and clinical trials generally match fish-oil effects at roughly two-thirds the omega-3 amount. The honest caveat: gram-for-gram omega-3, krill costs more — so the real comparison is convenience and absorption against price and dose, not a binary of better or worse.

Frequently asked questions

Is krill oil better than fish oil?

Better absorbed per gram, with fewer burps and built-in astaxanthin — but more expensive and backed by a smaller trial base. Both work; krill's advantage is efficiency, fish oil's is value and evidence depth.

Can krill oil trigger shellfish allergies?

Yes — krill are crustaceans, and people with shellfish allergy should avoid krill oil. Algal oil is the standard allergy-safe omega-3 alternative.

How much krill oil should I take daily?

1–3 g daily, providing 250–500 mg combined EPA/DHA, with meals. That omega-3 range is the meaningful dose; check the label's actual EPA/DHA content rather than the total oil weight.

The bottom line

Krill oil is the omega-3 category's efficiency play: phospholipid delivery, better absorption, no fishy burps, and comparable lipid effects at lower doses — at a price premium. Choose it for convenience and tolerance; choose fish oil for value; avoid both with shellfish allergy.

References

Krill oil absorption vs fish oil — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=krill+oil+absorption+phospholipid
Krill oil and lipids — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=krill+oil+triglycerides+trial
Krill oil and joint pain — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=krill+oil+knee+pain
Krill oil composition records. PubChem (National Library of Medicine). https://pubchem.ncbi.nlm.nih.gov/#query=krill%20oil