Cetoleic Acid

Fatty-acidBest with a meal

What is it

Cetoleic acid is a long-chain monounsaturated omega-11 fatty acid (22:1 n-11), found primarily in herring, capelin, and other fish oils. It is structurally similar to erucic acid (22:1 n-9) but with the double bond in a different position.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

EPA and DHA enhancement

Limited Evidence

Norwegian studies suggest cetoleic-acid-rich herring oil raises blood EPA/DHA more than would be predicted by direct content. Independent replication is limited.

How it works

Cetoleic acid has attracted research interest because it appears to enhance the body's endogenous conversion of plant omega-3 ALA into EPA and DHA. Norwegian research groups have shown that herring oil rich in cetoleic acid increases blood levels of EPA and DHA beyond what would be expected from its own (modest) long-chain omega-3 content alone. The mechanism is not fully understood but may involve effects on delta-6-desaturase or beta-oxidation.

Dosage

No standardized supplement dose. Herring or capelin oil typically provides 1 to 3 grams of cetoleic acid per 5 g of oil.

When and how to take it

Take with a meal containing fat for best absorption. Daily consistent intake is needed; effects on tissue fatty acid composition develop over weeks.

1 commercial form

Compare the main delivery options and what they’re best suited for.

Herring oil / capelin oil

Natural sources of cetoleic acid; less common than salmon-based fish oils.

Standard fish-oil absorption with food.

Safety

Cetoleic acid in fish oils appears well tolerated in trials. The structurally similar erucic acid (from rapeseed and mustard) has been associated with cardiac lipidosis at high intakes in animal models, but cetoleic acid has not shown the same effect at typical fish oil intakes.

Who should be cautious

People with fish allergy should avoid fish-oil sources. Insufficient data for purified cetoleic acid in pregnancy and breastfeeding.

Interactions

As part of fish oil, may have mild antiplatelet effects at high doses; combine with caution with anticoagulants. No specific interactions documented.

Food sources

Herring

Amount
100 g
%DV
—

Capelin

Amount
100 g
%DV
—

Frequently asked questions

Is cetoleic acid an omega-3?⌄

No. It is an omega-11 monounsaturated fatty acid, but it appears to enhance the body's conversion of omega-3 ALA into EPA and DHA.

Is it the same as erucic acid?⌄

No. Both are 22:1 fatty acids but with the double bond in different positions. Erucic acid (from rapeseed) has different safety considerations.

References

Cetoleic Acid on Wikidata — Wikidata link

Cetoleic Acid (ChEBI:32428) — ChEBI link

Cetoleic Acid (PubChem CID 5282771) — PubChem link

Cetoleic Acid on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Cetoleic Acid (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.