Finding the Right Fit: Which brand is good for cod liver oil?

October 6, 2025 •

5 min read

Historically, cod liver oil was a folk remedy used to prevent vitamin deficiencies, particularly rickets. Today, it remains a popular supplement, but with numerous options available, many wonder: Which brand is good for cod liver oil? Choosing a high-quality product is crucial to ensure purity and reap the full health benefits.

Quick Summary

This guide evaluates the best cod liver oil brands by focusing on key criteria like third-party testing, source, sustainability, and nutrient content. It compares top options such as Nordic Naturals, Carlson Labs, and NOW Foods, detailing how to distinguish a high-quality product based on certifications, freshness, and form, providing all necessary information for an informed purchase.

Key Points

Third-Party Certification is Key: Look for certifications like IFOS or NSF to ensure purity and potency, guaranteeing the supplement is free from heavy metals and contaminants.
Source Matters: High-quality cod liver oil typically comes from sustainably sourced, wild-caught cod in clean Arctic waters, like those around Norway.
Check for Freshness: The oil should not smell or taste rancid. Proper storage in dark bottles is essential to prevent oxidation.
Balance Nutrients Carefully: Be aware of the vitamin A and D content in cod liver oil, especially if you take other supplements, and consult a healthcare professional to avoid potential toxicity.
Consider Form and Taste: Choose between liquid and capsules based on your preference for potency, taste, and convenience. Flavored liquids can mask the fishy taste.
Top Brands to Consider: Brands like Nordic Naturals and Carlson Labs are consistently recommended for their high standards, while NOW Foods offers a good value option.

The Importance of High-Quality Cod Liver Oil

Not all cod liver oil is created equal. The quality of this supplement can vary dramatically based on the sourcing, processing, and purity standards of the manufacturer. Low-quality oils can be rancid, which diminishes the health benefits and may even increase inflammation, negating the purpose of taking the supplement in the first place. Furthermore, fish can accumulate environmental toxins like mercury, PCBs, and dioxins. Reputable brands go to great lengths to purify their oils and provide proof of testing to ensure they are safe for consumption. For consumers, this means looking beyond the price tag to evaluate a product based on specific, transparent quality indicators.

Key Factors for Choosing a Quality Brand

To make an informed decision, consider these factors when selecting a cod liver oil brand:

Third-Party Testing: Since supplements are not regulated by the FDA in the same way as drugs, independent third-party testing is the gold standard for verifying a product's purity and potency. Certifications to look for include the International Fish Oil Standards (IFOS) Program, NSF International, and the U.S. Pharmacopeia (USP) seal. These certifications confirm that the product contains the ingredients listed on the label and is free from harmful contaminants like heavy metals.
Source and Sustainability: The best cod liver oils are sourced from wild-caught, sustainably managed cod, often from the clean, cold waters of the Arctic Ocean near Norway. The Marine Stewardship Council (MSC) certification is an excellent indicator of sustainable fishing practices. Sustainable sourcing helps protect marine ecosystems from overfishing.
Processing Method: The best brands use processing methods that preserve the integrity of the oil, such as molecular distillation or gentle heating and centrifugation. This ensures the oil remains fresh and doesn't become oxidized, which can cause a rancid smell and degrade the omega-3s. Some brands offer 'fermented' cod liver oil, a cold-pressed method that some believe maintains more nutrients, though evidence for its superiority over high-quality, non-fermented oil is debated.
Freshness: You can often test a product's freshness by smelling or tasting it. A high-quality oil should have a mild, pleasant, or neutral odor, especially if flavored. If it smells distinctly 'fishy' or rancid, it may be oxidized and should be avoided. Proper packaging, such as dark bottles, helps protect the oil from light and air.
Omega-3 and Vitamin Content: Cod liver oil is prized for its naturally occurring omega-3s (EPA and DHA) and fat-soluble vitamins A and D. Compare the EPA and DHA levels per serving. Also, pay close attention to the vitamin A and D content, especially if you take other fortified foods or supplements, to avoid toxicity.
Form: Liquid vs. Capsules: Choosing between liquid or capsules is a matter of personal preference. Liquid often offers higher potency per dose and can be more cost-effective but has a stronger taste. Capsules are tasteless, convenient, and portable but may provide a lower dose per serving.

Comparing Top Cod Liver Oil Brands

Several brands consistently rank high for quality, sourcing, and testing. Here is a look at some popular options:

Nordic Naturals: A top-rated brand praised for its third-party testing (IFOS), sustainability (Friend of the Sea, MSC), and commitment to freshness. It offers various formulas, including unflavored and flavored liquids and capsules.
Carlson Labs: Another highly-respected brand known for its high-quality Norwegian cod liver oil. Carlson provides transparency with its third-party testing results and offers both liquid and capsule forms.
NOW Foods: Offers a good balance of quality and value. Many users appreciate the clean ingredients and lack of fishy aftertaste in their softgel products.
Green Pasture: Known for its fermented cod liver oil, a unique processing method that proponents claim retains more nutrients. It is often more expensive and has a distinct taste.

Cod Liver Oil Brand Comparison Table


Feature	Nordic Naturals	Carlson Labs	NOW Foods	Green Pasture (Fermented)
Source	Wild-caught Arctic cod	Wild-caught Norwegian cod	Quality cod oil source	Wild-caught Bering Sea cod
Processing	Molecular distillation	Molecular distillation	Standard purification	Lacto-fermentation
3rd-Party Testing	IFOS, Friend of the Sea, MSC, IGEN	IFOS (batches vary)	In-house & some third-party	No IFOS or major certification
EPA/DHA mg	Varies by product; High	Varies by product; High	Moderate to high	Varies, naturally occurring
Natural Vitamins	A & D included	A & D included	A & D included	A & D included
Forms	Liquid, Softgels	Liquid, Softgels, Minis	Softgels	Liquid, Gel, Capsules
Price	Premium	Premium	Mid-Range	Premium
Taste	Mild, often flavored	Mild, unflavored or flavored	Mild, typically tasteless	Pungent, unique flavor

Considerations Before You Buy

Consult a Healthcare Provider: Always consult your doctor before taking cod liver oil, especially if you are pregnant, nursing, on blood thinners (due to its blood-thinning effect), or have other medical conditions. They can help determine if it is appropriate for you and advise on suitable products.
Lifestyle: Your preference for liquid or capsules will depend on your lifestyle. Consider convenience, taste tolerance, and ease of use when choosing.
Budget: While quality should be the primary driver, brands vary in price. Determine a budget and research brands that meet your quality standards within that range.

Conclusion: Making Your Final Decision

Choosing a good cod liver oil brand hinges on prioritizing quality and transparency. Focus on products that are third-party tested and sustainably sourced, as this guarantees a supplement free from harmful contaminants and rich in beneficial nutrients. Nordic Naturals and Carlson Labs are widely regarded for their rigorous standards and excellent product quality. While NOW Foods offers a reliable and more budget-friendly alternative, and Green Pasture caters to those interested in the fermented option, it’s always best to check for current certification details and consider your personal tolerance for taste and form. Ultimately, the best brand for you is one that aligns with your health needs, dietary preferences, and quality expectations. You can find more information on certifications and product quality from independent programs like the International Fish Oil Standards (IFOS) website.

Frequently Asked Questions

Cod liver oil is specifically derived from the liver of codfish and naturally contains high levels of vitamins A and D, in addition to omega-3 fatty acids (EPA and DHA). Regular fish oil is extracted from the flesh of various fatty fish, such as sardines and mackerel, and contains omega-3s but does not have significant amounts of vitamins A and D unless added during processing.

Fermented cod liver oil, like that from Green Pasture, uses a traditional lacto-fermentation process. Proponents claim this preserves more natural nutrients. However, scientific evidence demonstrating its superiority over high-quality, purified cod liver oil is limited, and it often has a stronger taste and higher price point.

A fresh cod liver oil supplement should have a mild, clean, or even pleasant flavor if flavored. If you notice a strong, fishy, or stale odor or taste, the oil may have oxidized and become rancid. Rancid oil can be harmful and should not be consumed.

Neither form is definitively better; the choice depends on personal preference. Liquid oil offers higher potency per serving and can be more cost-effective but may have a strong taste. Capsules are tasteless, more convenient for travel, and offer pre-measured doses.

Third-party certifications, such as IFOS (International Fish Oil Standards), are crucial because they provide independent verification of a product's purity, potency, and freshness. Since supplements are not strictly regulated, these seals ensure the product meets specific quality standards for contaminants like heavy metals.

No, it is generally not recommended for pregnant women to take cod liver oil because of its high vitamin A content. Excessive vitamin A can be harmful to a developing baby. Pregnant women should consult their healthcare provider for safe omega-3 options, such as algae-based DHA supplements or specific formulas recommended during pregnancy.

Some people may experience mild side effects such as heartburn, stomach upset, or nausea, particularly when taking higher amounts. Additionally, the blood-thinning effect of omega-3s means that those taking blood thinners should consult a doctor before use.