Cod liver oil is a natural oil extracted from the liver of cod or other fish from cold seas. It is rich in omega-3 fatty acids (EPA and DHA) and naturally contains vitamins A and D.

The name cod liver oil comes from the Old Norse word “lysi,” which means “fat.” Originally, cod liver oil was extracted from the liver of cod, but in earlier centuries also from other fish species such as haddock, halibut, and even shark.

In the 18th and 19th centuries, cod liver oil was widely used in coastal areas of Norway, Iceland, and England. It was known as a natural remedy to maintain strong bones and resistance during dark, cold months. Green Pasture's cod liver oil is sustainably caught in Alaska.

Sometimes whale oil (from the blubber, not the liver) was also used for lighting, soap, and industrial applications, but that was not real cod liver oil. Whale oil contained hardly any vitamin A or D and was therefore not used as a dietary supplement, but rather as fuel or lubricant.

The “real” cod liver oil has always remained that from cod liver, due to its high content of omega-3 fatty acids and natural vitamins A and D. Later, it was discovered that fermentation is the most traditional and nutritious way to extract this oil without heating or chemical processing.

Green Pasture's cod liver oil has been sourced for years from sustainably caught cod from clean, cold waters around Alaska. The oil is traditionally fermented without heating, preserving the natural nutrients.

No. Fish oil is extracted from the fat of the whole fish, while cod liver oil comes from the liver. Therefore, cod liver oil naturally contains vitamins A and D, which are usually absent in regular fish oil. This is how fish oil is processed: Most fish oil undergoes an industrial refining and purification process where odor, taste, and color are removed. In the process, natural vitamins are often lost and later synthetically added. Fermented cod liver oil, on the other hand, is naturally preserved: without heating or chemical steps, preserving the original fatty acids and vitamins. Fermented cod liver oil, on the other hand, is naturally preserved: without heating or chemical steps, preserving the original fatty acids and vitamins.

Cod liver oil supports immunity, bones, teeth, and muscles. The omega-3 fatty acids contribute to the normal functioning of the heart and brain. Vitamin D also helps maintain good immunity.

Butter oil is the pure fat from milk of grass-fed cows. During preparation, water and proteins are removed, leaving only the nutritious milk fat. This fat is rich in vitamin K2 (menaquinone), which, together with vitamins A and D from cod liver oil, helps in the utilization of calcium in bones and teeth.

Dr. Weston A. Price discovered that butter oil and cod liver oil enhance each other's effects. The vitamin K2 from butter oil works together with the vitamins A and D from cod liver oil. This natural combination ensures better absorption and balance of fat-soluble nutrients and makes the product suitable as a daily, complete fatty acid source.

Yes, if used according to the recommended dosage. Cod liver oil is a natural source of essential fatty acids and fat-soluble vitamins that are often limited in modern diets. What can an excessive dose cause? Excessive intake can lead to surpluses of vitamin A or D, as these are fat-soluble and stored in the body. This can manifest as fatigue, headache, or nausea. Therefore, use it as directed and do not combine it with high doses of other vitamin A or D supplements.

The natural amount varies per batch, but on average, a serving provides 400 – 800 IU (10 – 20 µg) of vitamin D3.

On average, a serving contains 800 – 1200 µg of vitamin A (retinol), which falls within the safe daily intake for adults.

Only pure milk fat from butter oil; no milk proteins or lactose. Therefore, suitable for almost everyone with lactose intolerance.

No, butter oil is not the same as butter. Both come from milk, but butter oil is the concentrated, purified fat fraction of butter. During preparation, water, milk sugars, and proteins are completely removed. What remains is pure milk fat. Rich in vitamin K2 and more stable at room temperature than regular butter.