How to Choose the Best Fish Oil
What actually matters on a fish oil label?
- EPA mg + DHA mg, listed separately
- Form
- Triglyceride (TG)
- re-esterified Triglyceride (rTG)
- Ethyl Ester (EE)
| Form | Abbreviation | Relative bioavailability vs natural TG | vs ethyl ester |
|---|---|---|---|
| Re-esterified triglyceride | rTG / rTAG | 124% | ~1.7x EE |
| Natural triglyceride (fish body oil / CLO) | nTG / TG | 100% | ~1.4x EE |
| Ethyl Ester | EE | 73% | ~1.0x EE |
- Source
- Small wild fish such as
- Anchovy
- Sardine
- Mackerel
- Pollock
- Avoid large fish or simply unlabelled source (which is usual in many products), since large fish occupy higher levels in the food chain, their risk of heavy metal contamination is relatively higher.
- Small wild fish such as
- Third-party testing: USP / NSF / ConsumerLab when available, and most commonly, IFOS certification, we will cover more about this.
DHA vs EPA, what matters more?
Generally, a practical adult range is 1,000–2,000 mg combined per day. A balanced or slightly EPA-heavy ratio (about 1.5:1 to 2:1 EPA:DHA) covers most people. Choose a higher-EPA formula if the goal is lipids or mood. Choose more DHA if the user is pregnant, nursing, or targeting brain and eyes. The ratio only matters after the serving actually contains a meaningful amount of both.
What is IFOS?
IFOS stands for International Fish Oil Standards. It is a third-party certification program created in 2004 by Nutrasource in Guelph, Canada (now SGS Nutrasource). It exists only for marine oils, mainly omega-3 fish oil supplements. IFOS is not a government license, not an FDA approval, and not a medical claim. A company pays to have a finished product lot sent to accredited labs. The lab measures potency, oxidation, environmental pollutants, and heavy metals. If the lot meets the program’s limits, Nutrasource publishes a consumer report and allows the IFOS mark on that product line. You can check and verify specific brands or products on their website .
IFOS Certified Products Page
What does IFOS 5-star mean?
To pass IFOS’s 5-star criteria, the following items are usually checked
| Potency | Purity, Safety & Cleanliness | Stability | Heavy Metals |
|---|---|---|---|
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|
|
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After passing all the 4 big items, an extra star is added, totaling up to 5 stars.
Sample product’s test results, which passes all criteria as 5-star IFOS compliance, from an batch/lot on an IFOS report
What IFOS is not?
Generally, while having IFOS 5-star certificate is a good thing, it DOES NOT MEAN THAT
- It is a ranking of brands against each other
- A brand’s all products are aligned with IFOS criteria
- Not having IFOS certified means the product is bad
However, for those who just start looking for a fish oil ASAP with not experience, searching for an IFOS certified product would save a lot of hasseles for first timers.