Written by the Plenthera team (orthomolecularly trained). Scientifically reviewed in April 2026. Last updated: April 30, 2026.
Two stories converge in this category: on one hand, Nordic Naturals – the Norwegian brand that set the modern standard for purity with molecular distillation and IFOS certification. On the other hand, Green Pasture – the American brand that upholds the tradition of fermented cod liver oil, just as our grandparents knew it. At Plenthera, you'll find both. For those who want the most EPA/DHA per dose: Nordic Naturals. For those who want to follow the Weston A. Price tradition with natural vitamin A and D in the ratio as nature intended: Green Pasture.
Nordic Naturals vs Green Pasture vs Algae Oil
| Aspect | Nordic Naturals | Green Pasture | Algae Oil (vegan) |
|---|---|---|---|
| Production method | Molecular distillation | Traditional fermentation | Algae extract |
| EPA/DHA concentration | High (60-90%) | Lower, traditional | High |
| Natural vitamin A/D | In cod liver oil product | Yes (original ratio) | No |
| Certification | IFOS 5-star, MSC | Own quality standard | Variable |
| Taste | Mild, flavor variants | Strong, traditional | Mild, neutral |
| Target audience | Modern, clinical, sports | Traditional, paleo, ancestral | Vegan, pescatarian |
What is Fish Oil?
Fish oil is oil extracted from the flesh or liver of fatty fish. Key components are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) — two omega-3 fatty acids with EFSA-recognized claims for heart, brain, and vision.
Fish oil as a category within the broader omega-3 family deserves its own attention because it is the most clinically researched and historically oldest form of omega-3 supplementation. Cod liver oil was already given to children in Norway in the 19th century to combat rickets (vitamin D deficiency). What was in that cod liver oil – in addition to vitamin D, also EPA, DHA, and vitamin A – only came into scientific focus decades later.
Today, the market distinguishes itself on two axes: production method and quality standard. Modern molecular distillation (trademark: Nordic Naturals) uses vacuum and low temperature to create concentrates with high EPA/DHA levels — typically 60-90% omega-3 in the final oil. Traditional fermentation (trademark: Green Pasture FCLO) adheres to a centuries-old process where cod livers are fermented in barrels — no heat, no distillation, preserving the natural vitamin A and D in the original ratio as the fish had them.
Both approaches have their audience. For those who want maximum EPA and DHA per capsule — sports performance, clinical dosage, heart-and-brain theme — Nordic Naturals is the logical choice with IFOS 5-star certification. For those who follow the traditional wholefood story — paleo, ancestral health, Weston A. Price Foundation — Green Pasture is the heritage route. Also check our omega-3 category for the broader context with algae oil and krill oil as alternatives.
Fish Oil and EFSA — what is scientifically recognized?
EPA and DHA have extensive EFSA recognition. The following formulations may be literally used for fish oil products — provided the threshold value is met:
"DHA and EPA contribute to the normal function of the heart." (250 mg/day)
"DHA contributes to the maintenance of normal brain function." (250 mg/day)
"DHA contributes to the maintenance of normal vision." (250 mg/day)
"Maternal intake of DHA contributes to the normal brain development of the fetus and breastfed infants." (200 mg DHA/day in addition to the common 250 mg EPA+DHA)
"DHA intake contributes to the normal development of the eyes of infants up to 12 months." (100 mg DHA/day)
Thresholds as indicated above are crucial: a product must actually deliver that amount in a reasonable daily dose. Our Nordic Naturals products amply meet these thresholds (typically 500-1500 mg EPA+DHA per serving). Green Pasture FCLO delivers smaller absolute amounts of EPA/DHA per serving — always check the product label for the specific composition.
Nordic Naturals vs Green Pasture — two philosophies
Nordic Naturals (Norway, since 1995): Modern scientific approach. Molecular distillation under vacuum and low temperature. IFOS 5-star certified. MSC label for sustainable fishing. Strict TOTOX standard (<8, well below the GOED standard of 26). High EPA/DHA concentrations. Flavor variants (lemon, raspberry) for those who do not want a fishy taste.
Green Pasture (USA, since 2002): Traditional approach, inspired by historical research by Dr. Weston A. Price. Fermented Cod Liver Oil (FCLO) — cod livers are fermented in barrels without heat or solvents. The result: oil with natural vitamin A and D plus K2 in their original ratio. Strong taste, not pleasant for everyone, but for the Weston A. Price tradition and paleo audience the heritage choice.
Which do you choose?: For IFOS-certified purity and maximum EPA/DHA: Nordic Naturals. For a traditional wholefood approach with natural vitamin A and D: Green Pasture. Both have their audience — we deliberately carry both.
The Fish Oil Forms at Plenthera
Nordic Naturals Ultimate Omega
Flagship: high EPA/DHA concentration (1,280 mg per serving of 2 softgels). Citrus flavor. IFOS 5-star. For those who want maximum EPA/DHA.
Nordic Naturals Arctic Cod Liver Oil
Classic cod liver oil with natural vitamin A + D. Lemon flavor. IFOS-tested. For those who want cod liver oil without the fermentation route.
Nordic Naturals Children's DHA
Specifically tailored for children — lower dosages, flavor variants. EFSA-compliant.
Green Pasture Blue Ice Royal
Classic fermented cod liver oil + butter oil (vitamin K2). Heritage product, strong taste.
Green Pasture Fermented Cod Liver Oil (FCLO)
Pure FCLO without butter oil. The original Weston A. Price formula. For those seeking authentic traditional cod liver oil.
Algae Oil (vegan alternative)
For those who do not want fish — see our algae oil category. Delivers EPA/DHA from the same original source (algae) but plant-based.
How to Use Fish Oil?
Simple basic approach for fish oil:
- Determine your goal: maximum EPA/DHA (Nordic Naturals Ultimate Omega), traditional approach with vitamins (Green Pasture FCLO), or child-specific (Nordic Naturals Children's).
- Aim for at least 500-1,000 mg EPA+DHA per day for broad support.
- Take fish oil with a fatty meal for optimal absorption.
- Divide higher dosages over two moments (morning + evening).
- Store the bottle in the refrigerator after opening — fish oil oxidizes with light and heat.
- For FCLO: the taste is strong; mix with a spoon of honey or in yogurt if desired.
- For pregnancy: choose Nordic Naturals Prenatal or a DHA-focused formula. Cod liver oil with high vitamin A content during pregnancy: see advice from the NVWA and consult a doctor.
Myths and Misconceptions about Fish Oil
Myth 1: "All fish oil is the same — choose the cheapest."
Incorrect and risky. Fish oil is susceptible to oxidation and heavy metal contamination. Cheap fish oil can be rancid or contaminated. IFOS certification and TOTOX standard are more important than price.
Myth 2: "Fermented cod liver oil (FCLO) is always better than molecularly distilled oil."
Not automatically. Both have their advantages. FCLO retains natural vitamin A and D, molecular distillation provides higher EPA/DHA concentrations. Which is better depends on your goal and philosophy.
Myth 3: "Fish oil always smells and tastes fishy."
Incorrect for good quality. Fresh, high-quality fish oil barely tastes fishy. A strong fishy taste indicates oxidation — the oil is past its expiry date or stored incorrectly.
Myth 4: "Cod liver oil and fish oil are the same."
Not quite. Fish oil from flesh (salmon, anchovies) contains EPA/DHA. Cod liver oil (cod liver) contains EPA/DHA AND vitamin A and D in their original ratio. For those who only want EPA/DHA: flesh-fish oil. For a broader profile: cod liver oil.
Combining Fish Oil with Other Supplements
Fish oil is often combined with other supplements for cardiovascular, neurological, or general well-being. Popular combinations include:
- Vitamin D: naturally present in cod liver oil, or as a separate supplement.
- Vitamin E: antioxidant that limits oxidation of fish oil — often added to quality formulas.
- Vitamin K2: synergy with vitamins A and D in cod liver oil for bone and vascular health.
- CoQ10: cardiovascular cluster.
- Magnesium: for general cardiac support.
- Curcumin: joint-theme in combination.
- Algae oil: vegan alternative for those who eat less or no fish.
Frequently Asked Questions
What is fish oil?
Oil from the flesh or liver of fatty fish. Contains EPA and DHA omega-3 fatty acids. Cod liver oil also contains vitamins A and D.
What is the difference between fish oil and omega-3?
Fish oil is one source of omega-3. Omega-3 as a category also includes algae oil (vegan), krill oil, and plant-based sources (flaxseed, chia).
Which fish oil is best?
For IFOS-certified purity and high EPA/DHA: Nordic Naturals. For fermented traditional cod liver oil: Green Pasture FCLO.
What is fermented cod liver oil (FCLO)?
Cod liver oil via traditional fermentation without heat — Weston A. Price tradition. Preserves natural vitamins A and D in their original ratio.
What is the difference between Nordic Naturals and Green Pasture?
Nordic Naturals: modern molecular distillation, IFOS 5-star, high concentrations. Green Pasture: traditional fermentation, preservation of natural vitamins, paleo/ancestral tradition.
How much fish oil per day?
For EFSA claim 250 mg EPA+DHA. Broad support 500-1,000 mg/day. Upper limit EFSA: 5 g EPA+DHA/day.
When to take fish oil?
With a fatty meal for optimal absorption. Divide higher dosages over two moments.
What is a good TOTOX value?
GOED standard: <26. Premium brands (Nordic Naturals): often <8. Lower means fresher.
What does IFOS certification mean?
International Fish Oil Standards — independent purity, oxidation, and heavy metals testing. 5-star is the highest rating.
Fish oil for pregnancy — is it safe?
Yes, prenatal formulas or DHA-focused fish oil are recommended. Avoid cod liver oil with high vitamin A above 1500 µg/day during pregnancy.
Sources
- EFSA Regulation (EU) 432/2012 — EPA, DHA, ALA claims.
- EFSA NDA Panel — Tolerable Upper Intake Level of EPA, DHA and DPA (2012).
- GOED — Voluntary Monograph (quality standard for the omega-3 industry).
- IFOS — International Fish Oil Standards testing program.
- Price WA., "Nutrition and Physical Degeneration" (1939) — historical source for Green Pasture tradition.
Disclaimer: This text is for informational purposes only and does not replace medical advice. Fish oil is a dietary supplement, not a medicine. In case of doubt or if you are taking medication, we recommend consulting a doctor or orthomolecular therapist first.