Best Cod Liver Oil Supplements

Best Cod Liver Oil Supplements

Cod liver oil was once revered for its positive impact on health and wellness and may well be making a comeback in the 21st Century.


In earlier times, Vikings were known for having a barrel of it fermenting outside their door, taking a dose every morning with their famous primitive wooden spoons. They also used cod liver oil to light their lamps. Strangely enough, the best cod liver in the world still comes from Scandinavia.

The Viking Norseman were the first in recorded history to consume this omega-3 rich oil, though some scholars believe the Romans also used it as a curative for various ailments.

As time continued on, several other fishing cultures were known to use cod liver oil as food, fuel and a topically applied pain reliever. Most of Europe, England and Ireland all used it in their homes – and later in manufacturing processes when the Industrial Revolution began in the 1700’s.

In 1822, this natural curative was recognized for its positive effects on health, both when taken internally for everything that ailed people at the time, and rubbed on externally for treating rheumatoid arthritis and muscle/joint aches.

At the time, nobody in the medical community knew anything about vitamins or essential fatty acids like DocosaHexaenoic acid (DHA) and EicosaPentaenoic Acid (EPA); both of which are essential omega-3’s found in abundance in the oil. Learn more about the history surrounding cod liver oil here:

Continue reading to learn everything about how the oil is made, its many health benefits, warnings about its use, and how to select the most nutritious and safe cod liver oil for you and your family.

Atlantic Variety Considered the Best

There are several types of cod out there (see Wiki). Atlantic cod are believed to offer the healthiest and most nutritious livers, however they’re currently on the endangered list which has driven the price of cod and cod liver supplements up significantly over the years.

The reason cod are so plentiful in healthy fatty acids is because they’re the top predator of smaller fish such as eels, shellfish, minnows of all species, and in particular herring and sardines; two of the richest sources of the omega-3’s DHA and EPA in the ocean.


Top 5 Cod Liver Oil Supplements

#1View #2View #3View #4View #5View
Brand Green Pastures Carlson Carlson Now Foods Green Pastures
Overall Rating 5 / 5 5 / 5 4.9 / 5 4.9 / 5 4.8 / 5
Serving Size 2.5ml 5ml 2 Softgels 1 Softgel 2 Capsules
Price/Serving $0.51 $0.30 $0.15 $0.06 $0.26
Effectiveness 5 / 5 5 / 5  4.9 / 5 4.8 / 5 4.6 / 5
Quality 5 / 5 5 / 5 4.8 / 5 4.8 / 5 4.9 / 5
Taste 5 / 5 5 / 5 4.8 / 5 4.7 / 5 4.9 / 5
Digestibility 5 / 5 5 / 5 4.8 / 5 4.7 / 5 5 / 5


How it’s Made


Traditionally, cod liver oil was made by tossing a bunch of cod livers into a wooden barrel and topping them off with some fresh seawater. As the livers began to break down, they would give off their oil.

The mixture was left to sit for a year or more and used for everything from eating, to fuel for lanterns, to rubbing on sore parts of the body for pain relief. This is considered the best way to preserve the nutrition the oil offers, but modern toxic levels of mercury and pesticides in the fish make it necessary to clean and test the finished oil before it’s consumed.

Cooking and Pressing:

Most modern cod liver manufacturers steam the cod livers and press out the oil. Fermentation is rare, though still considered the best if you can find a manufacturer that takes pride in the quality of their product.

The main disadvantage of using this fast and easy process is that much of the naturally occurring vitamin D is lost through the extraction heating process. If it isn’t added back in after extraction, you’re left with a product that has several times the recommended daily dose of vitamin A and very little vitamin D.

Omega-3 levels are also compromised if the livers are heated to much.

Quality Control and Batch Testing:

The good manufacturers (ie., the ones that are concerned with quality) will batch test the finished cod liver oil for mercury levels, pesticides, and other toxins that are harmful to humans. This process is typically done both in-house and then later tested again by a third-party lab to ensure the utmost accuracy.

Health Benefits of Cod Liver Oil

1.Heart Health

Cod liver oil helps to balance cholesterol and fight the constant oxidative processes that are taking place throughout the body. Both of these processes are intimately intertwined, as cholesterol (specifically LDL or “Bad Cholesterol”) only becomes a problem for the walls of our heart and arteries when its oxidized by free radicals. Once this happens, the fatty cholesterol becomes sticky and the first building blocks of full blown arteriosclerosis are formed.

This article details an in-depth study that showed cod liver oil to be more effective at preventing heart failure than Crestor; a very common, widely used cholesterol lowering medication. Simply lowering the levels of LDL in the blood isn’t an effective preventative for heart disease because oxidative damage is still a constant. The omega-3’s in cod liver oil helps to stimy oxidation.

Common heart issues omega-3’s help with:

• Prevents cardiac arrythmia.
• Prevents blood clots within blood vessels.
• Prevents fatty deposits and fibrosis from occurring in the arteries.
• Helps blood vessels grow and repair faster.
• Prevents blood triglyceride levels from getting to high.
• Lowers blood pressure.

2.Vitamin D

The human body is able to generate its own vitamin D using the UV rays from the sun. In the hustle and bustle of the modern day “digital indoor lifestyle” most people globally are deficient in vitamin D. There are few dietary sources that provide us with this crucial nutrient – the sun being the most potent producer.

Vitamin D deficiency is linked to a number of serious health problems including dementia, certain cancers, erectile dysfunction, schizophrenia, and heart disease; the number 1 killer worldwide (source). This crucial vitamin is also needed by the gut in order to process calcium, leading to a whole host of problems including poor bone and teeth health along with heart and circulatory malfunction.

While the connection between cognitive impairment and vitamin D has not yet been studied extensively enough, people suffering from brain fog, dementia – and other degenerative diseases have reported astounding improvements to their brain function when consuming cod liver oil supplements.

Depending on the quality of the cod liver supplement ingested, a single serving of this lively oil can provide anywhere from 50 – 75% of our daily needs of vitamin D.

3.Brain Boosting

The human brain is very sensitive to inflammation. The concentration of omega-3 fatty acids in the brain is very high and when deficiency occurs, our poor brain often has to play second fiddle and sacrifice its needs for so that the rest of the body can continue to function at peak efficiency.

The link between low levels of vitamin D in the body and brain dysfunction has also been proved by exhaustive studies (source). There are many reasons for this including poor neurotransmitter function, inhibited immune activity, and high levels of toxicity – all of which vitamin D helps to control.

4.Respiratory Health

Omega-3 fatty acids, which are abundant in cod liver oil, help to curb inflammation in the lungs. This is particularly noteworthy for people suffering from inflammatory diseases ranging from mild to severe asthma, and more serious degenerative conditions like emphysema and chronic obstructive pulmonary disease (COPD). COPD is currently the number five killer globally.

A study completed at Japan’s Kagoshima University Hospital in December of 2005 concluded that a diet rich in omega-3s helped to treat and even put diseases like COPD into a remissive state, essentially curbing all flare-ups after supplementing with omega-3 supplements and improving their fitness levels considerably too (source).

There is also significant data to show that COPD and other inflammatory conditions in the lung are severely impacted when a patient isn’t getting enough vitamin D (source). As you’ve learned, cod liver can deliver 50 – 75% of our daily needs in just one teaspoon.

5.Topical Pain Reliever

The anti-inflammatory effects of cod liver oil mean that it can have a profound effect on people suffering from chronic joint pain and various forms of arthritis (source).

Because of rheumatoid arthritis, I was initially prescribed sulfasalazine 2000 mg as the basic medicine in combination with prednisone 5 mg daily. Initially, I tolerated the sulfasalazine quite well, after a few days came a kind of panic attacks, which were not completely gone after a while. Bought at

In the area of joint and muscle pain, cod liver oil has been used as a topical pain reliever since the Viking era (choose a brand that’s known for minimal to no “fishy” smell before using it in this way though!) If you’re already suffering from arthritis symptoms, it’s also recommended that you supplement with a quality glucosamine supplement which helps to increase the levels of synovial fluid in your joints.

6.Eye Health

The anti-inflammatory benefits of the omega-3’s in cod liver oil have already been discussed here at length. It should come as no surprise that the eyes, which are constantly bombarded with free radicals floating around in them, can benefit greatly from adequate levels of free-floating omega-3’s in the body.

The vitamin A content in cod liver oil is also extremely beneficial to the eyes, as this vitamin is needed in the formation of the conjunctival and corneal ocular surfaces. It also acts as a powerful anti-oxidant in the eyes. Studies have shown cod liver oil to be a major player in the treatment and prevention of glaucoma; one of the leading causes of visual impairment and blindness (source).

7.Faster Healing

As with all things cod liver, the Vikings first used this superfood as a topical treatment for superficial wounds. To this day, science hasn’t nailed down exactly why it works so effectively to speed up the healing of wounds, but it does. Some studies speculate that it’s the high vitamin A content that’s responsible (source).

8.Buying Considerations

Cod liver oil is definitely very good for boosting your health. Like any supplement, there comes a point of diminishing returns where taking too much can adversely affect your health by conflicting with other nutrients in the body. The manufacturing process and location where the fish are caught can also effect the healthfulness and purity of the cod liver products we take.

9.Retinol (Vitamin A)

When we get too much vitamin A, there’s a possibility of a debilitating condition called hypervitaminosis-A developing. It’s actually quite rare, but can happen when children consume more than 600 ug per day, or adults consume consistently high doses over 3000 ug a day for a prolonged period (around 3 weeks or longer).

For this reason, there are several nutrition authorities out there who refuse to recommend cod liver oil to their clients because of its vitamin A content (usually well over 100% the daily tolerable limit for adults). While it’s good to know that the medical community is watching out for us, this is generally a problem only with generics or cheaply made supplements.

If you note our (short) list of recommendations further down the page, you’ll see that the top manufacturers optimize the vitamin A to D ratios in their finished product. Check out the following post from Dr. Chris Kresser detailing the fallacies surrounding the connection between hypervitaminosis-A and cod liver oil, and confirming that it’s all about what kind you buy:

Essentially, don’t take more than the dose recommended on the bottle, or by your doctor and you’ll be just fine.


Vitamin A is absorbed at a rate of around 80 – 90% in the body. Should you consume too much during pregnancy it could potentially harm your baby. Whether you should consume it during pregnancy or not is a hot topic with some sources claiming it harms the infant, while there are still other studies that exist claiming that supplementation with it leads to smarter children (source). Evidence is also cropping up now that taking the right dose of cod liver oil during pregnancy significantly lowers the incidence of gestational diabetes in infants.

Ask your doctor if you have concerns, but it’s likely they’ll err on the side of caution and recommend that you do not, unless your vitamin-A levels are shown to be low.

11.Cod Liver Oil Can Reduce NSAID Needs

Several studies, such as this one have confirmed that cod liver oil can definitely reduce the needs for Non-Steroidal Anti Inflammatory drugs in those suffering from chronic pain by up to 30% after nine months of daily use.

The most promising group is those who have rheumatoid arthritis, since this is the group that’s been studied most extensively. However, anyone who deals with pain from inflammation will obviously benefit from the omega-3’s anti inflammatory effects.

Common NSAIDs:

• Celecoxib (Celebrex)
• Diclofenac (Cambia, Cataflam, Flector, Solaraze Gel, Voltaren, Voltaren Gel, Voltaren-XR, Voltaren Ophthalmic, Zipsor)
• Ibuprofen (Motrin, Advil, Nuprin)
• Indomethacin (Indocin, Indocin SR)
• Ketoprofen (Orudis, Actron, Oruvail)
• Ketorolac (Toradol)
• Meloxicam (Mobic)
• Naproxen (Naprosyn) or naproxen sodium (Aleve, Anaprox, Naprelan)
• Pentoxifylline (Trental)
• Prasugrel (Effient)
• Rivaroxaban (Xarelto)
• Antithrombin (ATryn, Thrombate 3)
• Apixaban (Eliquis)
• Argatroban
• Aspirin (Bayer, etc.)

How To Choose the Best Cod Liver Oil Supplement

The manufacturing process used to make and refine cod liver oil is very important when it comes to this supplement:

• Look for products that use third party testing for mercury and other common contaminants. Preferably using GOED standards and certification.

• Fermentation offers the highest quality end result, but can be expensive.

• Vitamin D is lost if the manufacturer doesn’t use fermentation to extract the oil. A sure sign of a manufacturer who isn’t concerned with your health is to read the label and check the vitamin A and D ratio: at minimum you should never buy a product that has more than twice the amount of A, as it does D; higher quality manufacturers will get the ratio of each very close to one another.

Cooking With Cod Liver Oil?

Please don’t try this!

If you surf around and ask Google this question, you’ll see an endless stream of forum and social media posts asking if cod liver oil is suitable enough for cooking. It really isn’t and for a couple of good reasons:

1. Taste: If you’ve ever taken a teaspoon of it, you likely know that people don’t necessarily consume cod liver oil for its pleasant taste and intoxicating aroma. The taste and odor doesn’t get better when you heat it; it gets worse. Much, much worse!

2. Nutrient Preservation: Heating it would destroy most, if not all the delicate omega-3’s and vitamin D it contains. This is one of the many reasons we aren’t supposed to overcook fish when we eat it too.

Stick with healthy olive or coconut oils for your cooking. Cod liver oil would be rather expensive to use for this purpose anyway.

Cod Liver Supplement Reviews

*We only recommend cod liver supplements where the vitamin A and D levels have been optimized, which means you’ll likely notice a few quality supplement brands that didn’t make this short list. You’ll find that several popular and nearly all generic branded cod liver oil manufacturers will have over 4000 iu of vitamin A (well above the daily “tolerable” limit according to the USDA) per serving, and with only miniscule amounts of vitamin D.

Green Pasture’s Blue Ice Royal Butter Oil / Fermented Cod Liver Oil Blend

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This Blue Ice Royal Butter from Green Pastures is quite simply the best cod liver supplement you can buy, also fortified with vitamin rich butter oil from grass fed cows. The Vikings are believed to be the very first to ferment cod livers using fresh caught livers combined with seawater many centuries before the practise found it’s way to Europe and England years later.

Fermenting the livers instead of cooking them, reduces the amount of omega 3’s and other nutrients that are lost, leaving you with a truly pure supplement, made to old world standards using new manufacturing processes to ensure freshness and purity. Very few manufacturers will spare the expense and time involved in fermenting the livers, since it takes nearly a year to complete the process from start to finish.

Green Pastures is all about offering a gold standard product, free from pesticides, mercury and other toxins. The nutritional values are never listed on Green Pastures products, but you can trust that their cod liver oil is the most nutrient-dense, health fortifying product on the market right now. Very highly recommended!

Carlson Norwegian Cod Liver Oil

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Carlson is the hands down leader (next to Green Pastures) when it comes to the freshest, most pure cod liver oil in the world, harvested from Norwegian cod, caught only in the winter months to ensure the most nutrient dense finished product. They also add a splash of lemon to help minimize burping and fishy after-taste.

One of the great benefits of harvesting liver from winter caught cod is that the omega 3 levels rise during this time, giving you 1 full gram per serving with a whopping 500 mg of DHA and 400 mg of EPA. Each single teaspoon serving also comes with 500 iu of vitamin D, 1250 iu of vitamin A, and 120 iu of vitamin E.

This product is regularly tested to AOAC protocols for potency, purity, along with minimum PCB, mercury and other contaminant content. Carlson ensures you get the freshest cod liver oil possible by replacing the air that sits inside the bottle with pure nitrogen to preserve freshness until you open it. Highly recommended!

Carlson Lightly Lemon Cod Liver Oil

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Not everyone has the stomach for chugging their cod liver oil by the teaspoonful. Carlson has taken their years of experience in making their winter-harvested cod livers into the best cod liver oil supplement ever, and used that knowledge to make these concentrated cod liver gels. They use the same quality fish used in their liquid product, also adding a splash of lemon to reduce burping and fishy after-taste, then put them in an easy-to-swallow soft gel.

You will pay more for this version however, since you have to swallow 5 capsules to equal the amounts of vitamin’s A, D and E, and omega 3 ratio8s you get from the loose liquid. One big advantage to using the concentrated soft gels is that the vitamin-A levels are lower in this version (750 iu per 5 capsules) than in the liquid version – perfect if you don’t like the idea of getting too much of it from supplement sources.

Now Foods Cod Liver Oil

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If you don’t like the price tag on Carlson products, but want to experience the health benefits that cod liver oil can offer, Now Foods is your next best bet. They use quality ingredients in all their products and this product follows in that long-standing tradition. It contains: vitamin A 50% RDA, vitamin D 68% RDA, 45 mg EPA, and 60 mg of DHA per serving. Whether you’re looking for memory enhancement, better skin, or to improve your HDL/LDL cholesterol ratio, this cod liver supplement will certainly help.

The one drawback is in the lower EPA and DHA content when compared to the Carlson products mentioned above. The RDA for both is 500 mg combined, meaning you really should consider taking an additional omega-3 supplement to make sure you’re getting enough.

Potential Side Effects

1.Mercury and PCB Toxicity

You don’t want to take cod liver oil made by a company that doesn’t have a good reputation. High levels of mercury, PCB’s and other toxic metals and chemicals have been found even in several popular brands over the years. Many a lawsuit has been filed against major brands like GNC, Twinlab, and Solgar for that same reason.

The fish stock used and manufacturing methods vary from one company to the next and it’s important to look for brands that belong to the Global Organization for EPA and DHA (GOED). To get a GOED seal on their products, members must used GOED-approved harvesting, manufacturing and testing processes, which ensures minimal toxicity and the best quality end result.

2.Fishy Aftertaste

While its usually only temporary, cod liver oil supplements can and do cause a fishy aftertaste, usually around ten minutes after consumption. As the oil hits the stomach it will cause stomach acid to rise, leading to belching, heartburn, and a sometimes unpleasant odor in the back of the mouth.

This is the price we pay for better health, so the aftertaste is somewhat unavoidable. However, many people do find relief by either taking their cod liver oil with food and/or by taking it with little pure lemon juice. Some supplements, like the Carlson products listed above, have lemon added to them for this reason.

3.Increased Bleeding and Bruising

This isn’t a universal fact, but some people who take cod liver oil supplements regularly report increases in the incidence of bruising and that wounds take longer to clot. This is because cod liver oil is a natural blood thinner. The same process that makes omega-3s healthy for your heart can cause bruising and increased clotting time when injured.

This side effect is rare and should be viewed as another price we pay for good, long term health. If you have a blood disorder that leads to increased bruising and bleeding, it should go without saying that you should take products containing omega-3s only on your doctor’s advice.

4.Potential for Elevated Blood Sugar

Some diabetics report that cod liver oil raises both their fasting and postprandial blood sugar readings. If you have diabetes, carefully monitor your sugar levels when taking cod liver oil and stop taking it if you feel your numbers are getting too high. Researchers at the University of Maryland Medical Center claim that the raises may result from the conversion of omega-3s to glucose.

However, don’t dismiss cod liver oil if you’re a diabetic, as fats aren’t the body’s preferred energy source and most diabetics won’t notice any raise in sugars at all.


This problem won’t be an issue if you purchase your cod liver oil from the manufacturers we recommend above and/or carefully scrutinize the labels of whatever products you’re considering. Hypervitaminosis-A is an overdose of vitamin A that can cause a whole host of health problems such as blurred vision, persistent nausea, calcification of the valves in the heart, decreases in calcium levels of the bones, and many others.

The upper tolerable limit for vitamin A is currently set at 3000 ug/day for adults. Children have to be much more careful with their upper tolerable limits set between 600 – 900 ug/day, depending on age group. Buy your cod liver oil only from manufacturers who optimize the levels of “A” in their products to prevent over-consumption of this vital, yet potentially dangerous vitamin.

Drug Interaction Warning

Blood Thinners

Taking extra omega-3s from sources like cod liver oil is a great way to reduce cholesterol and thin the blood naturally. However, if you’re taking blood thinners like those listed below, its important to discuss whether it’s safe to consume extra omega-3s with your family doctor and/or cardiologist.

Even taken on their own, omega-3s will increase the clotting time needed for wounds. Combine them with powerful prescription drug thinners and your risk for serious external and internal bleeding may increase significantly.

On the other side of this warning is hope for people who don’t like taking prescriptions and want to find a natural approach to keeping their heart and circulatory system healthy. See the list of other natural anticoagulants on Life Extension.

Common Blood Thinners:

• Alteplase (Activase)
• Bivalirudin (Angiomax)
• Cilostazol (Pletal)
• Clopidogrel (Plavix)
• Pradaxa
• Dipyridamole (Persantine)
• Drotrecogin alfa (Xigris)
• Eptifibatide (Integrilin)
• Fondaparinux (Arixtra)
• Heparin:dalteparin (Fragmin), enoxaparin (Lovenox), or tinzaparin (Innohep)
• Lepirudin (Refludan)
• Reteplase (Retavase)
• Streptokinase (Streptase)
• Tenecteplase (TNKase)
• Ticagrelor (Brilinta)
• Ticlopidine (Ticlid)
• Tirofiban (Aggrastat)
• Warfarin (Coumadin, Jantoven)


Cod liver oil offers a host of benefits to your all round health, when taken as directed. The anti-inflammatory and antioxidant properties it offers to the heart, lungs, joints and eyes have all been documented extensively.

It’s survived the test of time and the benefits far outweight the unproven risks associated with its use – provided you err on the side of caution and avoid buying the cheapest version available and instead go with trusted manufacturers that test their finished product for harmful toxins and also optimize vitamin A and D levels to proper standards.

This Post Has 3 Comments

  1. Gabby

    I had no clue cod liver oil was so good! My fish oil pills say just that, fish oil, they don’t mention what type of fish are they from. Is that bad? They’re not cheap either… I eat a lot of fish, 3-4 times a week, being it salmon, tuna, mackerel, and I thought this combined with the pills was enough. I’ll try cod liver oil next time when my pills run out, I’m very curious how these work.

  2. Ivanna Santino

    I’m 59 years old and female. I was diagnosed a couple of months ago with COPD and I was beyond scared! My lung function test indicated 49% capacity. After having had flu a year ago, the shortness of breath, coughing and chest pains continued even after being treated with antibiotics. I’ve been smoking two packs a day for 36 years. Being born without a sternum caused my ribs to be curled in just one inch away from my spine, resulting to underdeveloped lungs. At age 34 I had surgery and it was fixed. Unfortunately my smoking just caused more damage to my already under developed lungs. The problem was having is that I enjoy smoking and don’t want to give up! Have tried twice before and nearly went crazy and don’t want to go through that again. I saw the fear in my husband and children’s eyes when I told them about my condition then they start to find solution on their own to help my condition.I am an 59 now who was diagnose COPD emphysema which I know was from my years of smoking. I started smoking in school when smoking was socially acceptable. I remember when smoking was permitted in hospitals. It was not known then how dangerous cigarettes were for us, and it seemed everybody smoked but i was able to get rid of my COPD lung condition through the help of total cure herbal foundation my husband bought, totalcureherbsfoundation .c om has the right herbal formula to help you get rid and repair any lung conditions and cure you totally with their natural organic herbs. I wish anybody who starts smoking at a young age would realize what will eventually happen to their bodies if they continue that vile habit throughout their life.

  3. Fitoru Keto

    Nice post! I wonder if I can find these products here in our place. I so want to try these. Thanks for sharing!

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