International Fish Oil Standards (IFOS): Full Guide

IFOS overview

• Third‑party testing program administered by Nutrasource.
• Checks three areas: purity, potency, and freshness.
• Publishes batch‑specific reports so users can verify results.

Certification: purity, potency, freshness

• Purity (contaminants)
  • Heavy metals (e.g., mercury), dioxins, polychlorinated biphenyls measured against strict limits.
  • Results reported per batch; methods follow recognized analytical standards.
• Potency (label accuracy)
  • Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per serving are quantified and compared to the label claim.
  • Reports show measured milligrams of EPA and DHA and pass/fail status.
• Freshness (oxidation)
  • Peroxide Value and Anisidine Value are measured; both indicate oxidation stage.
  • Total Oxidation (TOTOX) is calculated as 2 × Peroxide Value + Anisidine Value (see the TOTOX guide).
  • Industry guidance often cites Peroxide Value ≤ 5, Anisidine Value ≤ 20, TOTOX ≤ 26 for finished oils (see references).

Testing metrics: Peroxide Value, Anisidine Value, TOTOX

• Peroxide Value (meq O₂/kg): primary oxidation products; rises early.
• Anisidine Value (unitless): secondary oxidation products (aldehydes); rises later.
• TOTOX = 2 × Peroxide Value + Anisidine Value: combines both stages into one number.

How to read an IFOS batch report

• Match the lot/batch number on the bottle to the report.
• Check eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) measured vs label claim (mg per serving).
• Check Peroxide Value, Anisidine Value and TOTOX values and note units.
• Confirm the test date and that the result applies to your lot.

Real brands and products

Examples from our catalog (not endorsements; for search context only):

• Nordic Naturals: Ultimate Omega, ProOmega.
• Life Extension: Super Omega‑3 EPA/DHA Fish Oil.
• NOW Foods: Ultra Omega‑3 Fish Oil, DHA‑1000.
• Pure Encapsulations: EPA/DHA Essentials.
• Thorne: Super EPA, Super EPA Pro.

Key points

• IFOS focuses on product quality (what is in the bottle).
• Peroxide Value, Anisidine Value and TOTOX give a snapshot of freshness at test time.
• Use our catalog to view product names and forms; see the TOTOX guide for oxidation basics.

References

1. Shahidi F, Ambigaipalan P. Fishing for answers: oxidation of fish oil supplements. Critical Reviews in Food Science and Nutrition. 2018. PMC
2. Jackowski SA, et al. Oxidation levels of North American over‑the‑counter omega‑3 supplements. Journal of Nutritional Science. 2015. PMC
3. Albert BB, et al. Fish oil supplements in New Zealand are highly oxidised and do not meet label claims. Scientific Reports. 2015.
4. Shahidi F, Zhong Y. Lipid oxidation and improving the oxidative stability. Chemical Society Reviews. 2010. DOI
5. Jacobsen C. Some strategies for the stabilization of long chain n‑3 PUFA‑enriched foods: A review. European Journal of Lipid Science and Technology. 2010.

The products listed are not endorsements; they are examples drawn from our database.

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