The Consumer’s Fish Oil Guide

white plastic bottle on side with best fish oil soft gels spilling out


Fish is an excellent source of the omega 3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Omega 3 fatty acids are found in the fatty tissue of fish that eat phytoplankton (algae) or consume other fish that have accumulated EPA and DHA in their bodies.

There’s conflicting research on the health benefits of omega 3 fatty acids, but several studies show they can help reduce inflammation and lower elevated triglyceride levels.

Fish oils have become one of the most popular nutritional supplements.  Recent industry numbers estimate the world fish oil market at just under $2 billion, and its predicted to climb to over $3 billion by the mid-2020’s.

Unfortunately, the fish oil industry isn’t completed regulated and not all fish oils are created equal. If you compare two different fish oil products side-by-side, you may find a difference in the actual ingredients, purity, dosage amounts and freshness.

All fish oils can be made by a variety of methods and companies may use different marketing terms or slogans to help sell their product. Examples of such terms are molecular-distillation, triple-refined, double-strength, fractionally-distilled and many more.

We believe that the best fish oil will have excellent overall purity and quality of the ingredients, as well as the consumer getting exactly what’s stated on the ingredient label.

In this Complete Guide to The Best Fish Oils, you’ll learn about different types of fish oil products, comparing fish oil soft gels vs liquids, the purpose of enteric-coated fish oils, choosing fish oils for children, in-depth product reviews and more.



What’s the Difference Between Norwegian Fish Oil, Pharmaceutical-Grade and Prescription Fish Oils?


Summary of Terms:

  1. Norwegian fish oils are made from fish caught in the Norwegian Sea.
  2. Pharmaceutical-grade fish oils are products that claim to follow the methods used to make pharmaceutical medications either through manufacturing, quality control or purification.
  3. Prescription fish oils are omega 3 fatty acid products made in FDA-approved labs and require a Doctor’s prescription.

The following information will take a closer look at each category.

What are Norwegian Fish Oils:

Norwegian fish oils are primarily made from fish caught in the Norwegian Sea, such as haddock, Atlantic salmon, herring and Atlantic halibut.

nordic naturals fish oil

Nordic Naturals is a Norwegian Fish Oil

According to The Norwegian Seafood Council, Norway has some of the largest cod stocks in the world. Cod liver oil was one of the first fish oils to be used by ancient Norwegians.

Norwegian fish oils can be made by different methods.  In the 1980’s, the fish were boiled until the oil rose to the top of the vat (a process called ‘rendering’). Unfortunately, this process was not able to remove all the toxins in the flesh of the fish, such as PCB’s and mercury, and these unwanted contaminants remained in the fish oil. 

New innovations in chemical engineering, such as molecular distillation, can now remove most of the saturated fats and PCB’s by distillation. The result is a highly-purified fish oil.

Are Norwegian fish oils superior to other types of fish oil?  Some marketers will claim that the fish used to make Norwegian fish oils contain naturally higher levels of omega 3 fatty acids and less exposure to mercury and contaminants.

We believe that the overall quality and purity of the fish oil is more important than what type of fish were used to make the oil.

Examples of fish oils made from fish caught in the Norwegian Sea are Nordic Naturals and Carlson Labs.


What are Pharmaceutical-Grade Fish Oils:

Pharmaceutical-grade fish oils is a term used by many fish oil companies to describe their product. One of the problems calling a product ‘pharmaceutical-grade’ is that it’s not an FDA-regulated term and any manufacturer can use it to describe their product. 

In our article on pharmaceutical grade fish oil, we highlight how there’s no standardized or regulated method for making a ‘pharmaceutical-grade’ fish oil. So it’s up to the consumer to determine the validity and credibility of the marketer’s claims about a specific product.

pharmaceutical grade fish oil capsules in blister pack

Some of the biggest concerns for consumers are exposure to mercury and side effects from fish oils. Choosing a product claiming to be ‘pharmaceutical-grade’ may help alleviate some of these concerns, however, this doesn’t mean that the product will offer any benefits.

We believe that a ‘pharmaceutical-grade’ fish oil should provide the following:

  • High concentrations of EPA and DHA
  • Undetectable levels of mercury, PCB’s, dioxins and other contaminants
  • Made in FDA- approved labs following Good Manufacturing Practises (GMP)

Any fish oil product that undergone testing or verification by a 3rd party may help consumers feel more confident about the quality of the product.


Certificate of Analysis for Fish Oils

Some fish oil companies may hire a 3rd party laboratory to analyze their products and provide a Certificate of Analysis (COA).

The certificate shows that the fish oil has been analyzed for the amount of omega 3 fatty acids and any detectable levels of mercury, dioxins and other contaminants.

Here’s a sample Certificate of Analysis from PurityProducts Ultra Pure Omega 3.  This particular certificate indicates the actual measured amounts of EPA and DHA, any detectable levels of contaminants (including mercury, arsenic, PCB’s) and much more.  The certificate also indicates the date of manufacture and the specific batch and lot numbers of the product that was analyzed.

Not all fish oils come with a Certificate of Analysis and there are a number of different companies or laboratories that will provide this service.


Examples of 3rd Party Certification Organizations:

Guide to IFOS Fish Oils – IFOS (International Fish Oil Standards) is an independent lab that analyzes and certifies fish oils for other companies. In this article we discuss how these products are rated according to criteria set by many international organizations and showcase some sample products that are IFOS-certified.

GOED (Global Organization for EPA and DHA) –  follows guidelines set out in GOED Voluntary Monograph and checks for omega 3 fatty acids levels and environmental contaminants, such as mercury, PCB’s, dioxins and furans.

IVO (International Verified Omega-3) – claims to test for over 400 potential contaminants, compliance with regulatory fishing and harvesting methods, and internationally-approved processing and manufacturing methods to ensure the fish oil’s safety, purity and potency. 

Many of the above organizations may follow national or international standards set forth by different regulatory bodies.

Some examples of these regulatory bodies are:

  • Council for Responsible Nutrition – a trade organization representing dietary supplement manufacturers and suppliers. It’s voluntary to join and its members are expected to follow federal and state regulations governing dietary supplements for safety, manufacturing and quality control 
  • United States Pharmacopeia (USP) –  helps supplement manufacturers stay competitive by providing the USP Verified Mark for their products. The USP Verified Mark on a fish oil product ensures consumers that the item contains what’s stated on the label, doesn’t contain harmful contaminants and was made according to FDA current Good Manufacturing Practices (GMP).
  • Europena Pharmacopeia Standards (EPS) – operating under the European Directorate for the Quality of Medicines (EDQM), the European Pharmacopeia Monograph sets standards for the quality control of medicines and some nutritional supplements.   
  • IVO (International Verified Omega-3) – an independent, not-for-profit organization that offers certification of fish oils that meet a comprehensive set of quality checks, including testing for almost 400 possible contaminants. Our article on Costco’s Kirkland Fish Oil Review revealed that they are certified by IVO.   

Consistent and regular testing is the only way to ensure you’re getting a highly-purified product that contains what’s stated on the ingredient label.


What’s a Prescription Fish Oil?

These are fish oils that have gone through extensive testing and research, have proved to the FDA that it does what it’s prescribed for, contains exactly what’s stated on the ingredient label and discloses any possible side effects from the product.

All prescription fish oils are manufactured in FDA-approved facilities and must follow strict guidelines during the entire manufacturing process. 

Prescription fish oils may contain high concentrations of certain isolated omega 3 fatty acids; sometimes considerably higher when compared to some store-bought fish oils.

Examples of prescription fish oils are Lovaza and Vascepa. You’ll also need a doctor’s prescription to get these types of products.

prescription fish oil

Lovaza Soft Gels

The main benefits of prescription fish oil is you get exactly what is stated on the ingredient label.  One of the biggest questions for many is what is the correct fish oil dosage to use?  The use of prescription fish oils guarantees a specified omega 3 fatty acid dosage based on your doctor’s recommendation.

Are Prescription fish oils better than regular fish oils? Based on the research and FDA-approval process required for these types of products, we believe they are superior to many off-the-shelf products when it comes to overall quality, purity and proven health benefits.  However, the higher cost and need for a prescription may be a barrier to some consumer’s budgets.



Since the fish oil industry isn’t completely regulated, consumers may need to research the company that makes their fish oil.

  • Prescription fish oils will provide exact EPA and DHA dosages and meet all FDA-approved guidelines for pharmaceutical medications. However, prescription fish oils require a doctor’s prescription and may cost significantly more than store-bought fish oils.
  • Products claiming to be ‘pharmaceutical-grade’ fish oils may use a 3rd party laboratory to analyze and certify their fish oil, but you may get different concentrations of EPA and DHA, compared to a prescription fish oil.  There is also no guarantee that what you see on the ingredient label is what you’ll get in every single bottle.
  • Norwegian fish oils are products made from fish sourced from the Norwegian sea which may or may not provide assurances of quality or purity.

Fish Oil: Soft Gels vs Liquid – Which is Better?


liquid fish oil and soft gels

Bottle of liquid fish oil and soft gel capsules


In our article, “A Closer Look at Liquid Fish Oil vs Capsules”, we looked at the pros and cons of each and which is the best type to buy.

To summarize, fish oils come in bottled liquids and soft gel capsules; and depending on your personal preference, there are advantages and disadvantages to each type.

Fish oil soft gels (or capsules) are very common.  The fish oils are encapsulated in soft gels which are usually made from gelatin.  The gelatin can be made from animal or plant-based materials.  Animal-based gelatin is usually sourced from the skin, hooves, connective tissue and bones of cows or pigs.

Some of the advantages of soft gel capsules is they’re generally tamper-proof which helps avoid contamination, they can help keep the ingredients stable and they also provide a uniform dosage. However, some consumers may have difficulty swallowing pills or they may be reluctant to products made from animal sources.

Some people may have health issues that affect their ability to properly digest fish oil soft gels or capsules. Enteric-coated fish oils are capsules or soft gels that have a special coating which may help improve digestion and absorption.

enteric coated fish oil

Enteric coated and Non-coated soft gels

Some of the Pros and Cons of Enteric-Coated Fish Oil include enhanced absorption and digestion; however, some products may only be sold in lower dosages or they could use synthetic or artificial ingredients for the enteric coating.

Liquid fish oils are bottled oils that are available in many different flavors. The most common liquid fish oils are lemon-flavored, such as lemon-flavored cod liver oils.  The flavorings can be made from natural or artificial ingredients. Fish oils for children are sold with these special flavorings to make them more agreeable to a child’s palate.

Liquid fish oils usually provide a higher dosage of omega 3 fatty acids per spoonful, compared to a single soft gel or capsule.  This is because a teaspoon of liquid fish oil is about 5 grams, where as a single fish oil soft gel is usually only 1000 mg (1 gram) in size.

Choosing between a fish oil soft gel and bottled liquid may come down to what specific fish oil dosage your want and if you experience any side effects from fish oils.


Product Reviews of Fish Oil Products:

Based on the above criteria, we have included a few product reviews to help guide you:

Consumer’s Guide to Nature Made Fish Oil – this is a popular fish oil supplement sold by Pharmavite, a nutritional supplement company based in Northridge, California. They have a number of different fish oil products based on overall omega 3 concentrations and enteric-coated fish oils.

Is Spring Valley Fish Oil the Best Fish Oil? – this is Walmart’s private label brand that includes a wide range of different ingredients and omega 3 dosages. We take a closer look at the overall purity and quality of this popular big-box retailer brand.

Kosher Fish Oils – What You Need to Know – With a wide range of flavorings and ingredients used to make fish oils, you may need to find a kosher fish oil. We take a closer look at kosher fish oils and how to choose the best kind.



When it comes to buying fish oils, there are a number of important factors to consider if you want a highly-purified product that will provide what’s indicated on the ingredient label. 

Aside from using prescription fish oils, you should look for the following criteria:

  1. Provides the amount of EPA and DHA you require
  2. Is available in either bottled liquids or soft gel capsules
  3. Verification of purity and quality, either through a Certificate of Analysis or other 3rd Party Laboratory Testing
  4. Is there any additional ingredients or additives added to the fish oil?

Choosing high quality nutritional supplements that are proven to be safe, effective and affordable can help you achieve the benefits you seek.


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Author Details
Author Details
Kevin is a full-time blogger with a passion for functional, whole food nutrition. A former Registered Respiratory Therapist with over 25 years experience in Intensive Care and Emergency Medicine, he also has additional training as a Certified Natural Products Advisor. He enjoys a vibrant lifestyle that includes healthy foods, workouts focusing on core strength with flexibility and longboarding to stay fit and agile.