Many people take fish oil supplements on a daily basis.
In addition to supporting the brain, eyes, and heart, fish oil can fight inflammation in your body (1).
Many health professionals recommend it. However, you may not know what the right dosage is for you.
This article explains how much fish oil you should be consuming for optimal health.
Fish oil can be incredibly beneficial for your health.
It contains omega-3 fatty acids that protect your heart. You need to get omega-3s through your food because your body cannot make them on its own.
Some fish oils also provide vitamin A, an important antioxidant, and vitamin D, which is essential for bone health and overall immunity.
The main omega-3 fatty acids in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which affect the development and function of the brain (2 3, 4).
Fish oil is an excellent source of these fatty acids.
If you don’t eat oily fish on a regular basis, getting enough EPA and DHA can be very difficult – since most other food sources of omega-3s are in the form of alpha-linolenic acid (ALA). ALA doesn’t seem to have the same beneficial effects as EPA and DHA (5, 6).
In addition, the typical western diet is low in omega-3 compared to omega-6. Therefore, supplementing with fish oil can be a big boost (7, 8, 9).
Fish oil contains the omega-3 fats EPA and DHA, which are essential for the development and function of the brain. If you don’t eat oily fish on a regular basis, consider taking nutritional supplements.
There is no hard and fast recommendation for the amount of fish oil that you should ingest.
However, there are recommendations for total omega-3 intake as well as EPA and DHA.
The daily reference dose (RDI) of combined EPA and DHA is 250–500 mg (4, 10).
When buying fish oil supplements, be sure to read the label to determine how much EPA and DHA it is providing. Typically, 1,000 mg of fish oil provides around 300 mg of combined EPA and DHA (11).
The RDI for total omega-3 is 1,100 mg for women and 1,600 mg for men (11).
Most people get omega-3s in their diets from foods like flaxseed, soybean oil, and walnuts – but these contain ALA.
While your body can convert ALA to EPA and DHA, you are unlikely to make adequate amounts of these fatty acids yourself. If you don’t eat around two servings (8 ounces or 224 grams) of fatty fish a week, you could be deficient in EPA and DHA (4, 12, 13).
Generally speaking, up to 3,000 mg of fish oil per day is considered safe for adults (14).
EPA and DHA are essential for the normal development of the fetus. DHA in particular accumulates in the brain in the last trimester of pregnancy (12, 15).
However, many pregnant women do not meet the RDI for these fatty acids (4).
Supplementing with EPA and DHA during pregnancy can also benefit your child in infancy and childhood. Potential benefits include improved problem-solving skills and a reduced risk of asthma and food allergies (16, 17, 18).
The WHO recommends 300 mg of combined EPA and DHA per day – 200 mg of which should be DHA – during pregnancy (19).
Since most fish oil supplements contain more EPA than DHA, you should try to find one with a higher percentage of DHA (1).
Be careful with cod liver oil during pregnancy as it contains large amounts of vitamin A. Too much vitamin A can affect the development of the fetus.
Just 1 teaspoon (4 ml) of cod liver oil provides 2,501 IU of vitamin A – that’s about 97% of the RDI during pregnancy (20, 21, 22).
Infants and children
The adequate intake of omega-3s for infants up to one year of age is 500 mg, which gradually increases to the normal intake of adults at 14 years of age (11).
Likewise, the recommendations for EPA and DHA vary according to age.
For example, a 4-year-old needs about 100 mg of combined EPA and DHA, while an 8-year-old needs about 200 mg (23).
Fish liver oils for children also naturally provide some vitamins A and D – since these are stored in fish liver – while other fish oil supplements may contain additional vitamins D, A and E. Vitamin E keeps the oil stable and can extend its shelf life.
When purchasing a fish oil supplement for an infant or child, try to find ones that are specific to their stage of life to ensure the right amount of nutrients.
While there are set recommendations for EPA and DHA for healthy adults, pregnant women – as well as infants and children – have different needs.
To keep heart healthy, make sure you are getting enough EPA and DHA.
Up to 1,000 mg of total EPA and DHA per day is recommended for people with coronary artery disease and at risk of a heart attack (24, 25).
However, a recent review found that additional intake of EPA and DHA, whether through diet or supplements, had little or no effect on reducing the risk of heart attack (26).
However, the study found that fish oil can reduce elevated triglycerides in your blood, which is a risk factor for heart disease. It can also increase the “good” HDL cholesterol.
The higher the intake of EPA and DHA, the stronger the effect on the triglycerides. In two studies, 3.4 grams of combined EPA and DHA reduced triglycerides by 25–50% after 1–2 months (27, 28).
Fish oils can also lift your spirits. Research shows that supplementation with EPA and / or DHA can improve symptoms of depression (29, 30, 31).
However, because studies use irregular doses, there is no conclusive recommendation for specific amounts of fish oil or EPA and DHA for mental health.
One study found that a combined daily dose of 1,400 mg EPA and DHA reduced symptoms of depression in young adults after three weeks, while another study found 2,500 mg EPA and DHA reduced anxiety in healthy people (32, 33) .
In one analysis, omega-3 supplements with higher EPA to DHA ratios were most effective at treating depression. Fish oils naturally contain higher proportions (34).
Increased intake of omega-3s can also reduce inflammation in your body and potentially reduce joint inflammation (35, 36, 37).
However, a review of available studies suggests that EPA and DHA supplements do not consistently benefit people with osteoarthritis (38).
Hence, it is difficult to recommend a specific dose of fish oil or fatty acids for joint health.
Nevertheless, in a study with 75 people with knee osteoarthritis, 1,000 mg of fish oil per day – including 400 mg of EPA and 200 mg of DHA – significantly improved knee performance.
Interestingly, a higher dose of 2,000 mg did not improve knee function any further (36).
Fish oil can help reduce triglycerides, improve mood, and promote joint health – but dosage recommendations vary depending on the study and the specific health status.
Fish oil supplements provide EPA and DHA – and many have vitamins A and D.
In the meantime, general omega-3 supplements may or may not contain EPA and DHA, depending on whether they’re made from fish, seaweed, or vegetable oils.
If your omega-3 supplement is made from seaweed, it will contain EPA and DHA. Usually these supplements are high in DHA and low in EPA (14).
On the other hand, fish oil supplements are likely to have higher levels of EPA than DHA, while vegetable oil-based supplements contain high levels of ALA.
Although all omega-3 fatty acids have benefits, EPA and DHA are the most beneficial (5).
If you don’t eat oily fish on a regular basis, a fish oil supplement can increase your EPA and DHA levels. However, if you don’t consume fish products, an algae-based dietary supplement is a good alternative.
Otherwise, taking an omega-3 supplement made from vegetable oils will help increase your overall omega-3 fatty acid intake – but likely not increase your EPA or DHA levels.
Not all omega-3 fatty acids are created equal. While fish oil supplements provide EPA and DHA, most plant-based omega-3 sources provide ALA, which is difficult to convert to EPA and DHA.
A great amount of research supports supplementing with fish oil.
While there are no conclusive recommendations, 250–500 mg of combined EPA and DHA per day – of which fish oil is an excellent source – is enough for most healthy people.
Keep in mind that this can vary based on your needs. In addition, pregnant women, infants, and children may require different dosages.
If you do decide to increase your intake, make sure you choose an omega-3 supplement that contains the recommended amount of EPA and DHA.