Fish Oil Dosage: How Much Should You Take Per Day?

Fish oil can be incredibly beneficial for your health.

It contains omega-3 fatty acids, which protect your heart. You must get omega-3s from your diet, as your body cannot make them.

Some fish oils also supply vitamin A, an important antioxidant, and vitamin D, which is essential for bone health and overall immunity.

The main omega-3s present in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which impact brain development and function (2 3, 4).

Fish oil is an excellent source of these fatty acids.

If you do not eat oily fish regularly, it can be very difficult to get enough EPA and DHA — because most other food sources of omega-3 are in the form of alpha-linolenic acid (ALA). ALA does not appear to have the same beneficial effects as EPA and DHA (5, 6).

Furthermore, the typical Western diet is too low in omega-3 compared to omega-6. Therefore, supplementing with fish oil can be a great boost (7, 8, 9).

Summary

Fish oil contains the omega-3 fats EPA and DHA, which are vital for brain development and function. If you don’t eat fatty fish regularly, you may want to consider supplements.

There is no set recommendation on the amount of fish oil you should take.

However, there are recommendations for total omega-3 intake, as well as EPA and DHA.

The reference daily intake (RDI) of combined EPA and DHA is 250–500 mg (4, 10).

When buying fish oil supplements, make sure to read the label to determine how much EPA and DHA is provided. Typically, 1,000 mg of fish oil supplies around 300 mg of combined EPA and DHA (11).

Healthy Individuals

The RDI for total omega-3 is 1,100 mg for women and 1,600 mg for men (11).

Most people get some omega-3 in their diet from foods such as flax seeds, soybean oil and walnuts — but these contain ALA.

While your body can turn ALA into EPA and DHA, you likely won’t form adequate levels of these fatty acids on your own. Unless you are eating about two portions (8 ounces or 224 grams) of oily fish per week, you could be lacking EPA and DHA (4, 12, 13).

Generally, up to 3,000 mg of fish oil daily is considered safe for adults to consume (14).

During Pregnancy

EPA and DHA are essential for normal fetal development. DHA, in particular, accumulates in the brain during 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 during 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).

As most fish oil supplements hold more EPA than DHA, you should try to find one with a higher ratio of DHA (1).

Be careful with cod liver oil during pregnancy, as it harbors large amounts of vitamin A. Too much vitamin A can impair fetal development.

Just 1 teaspoon (4 ml) of cod liver oil provides 2,501 IU of vitamin A — which is about 97% of the RDI during pregnancy (20, 21, 22).

Infants and Kids

The adequate intake of omega-3 for infants up to 1 year old is 500 mg, which gradually increases to normal adult intake at 14 years (11).

Likewise, the recommendations for EPA and DHA vary depending on age.

For example, around 100 mg of combined EPA and DHA is required for a 4-year-old, while an 8-year-old child needs about 200 mg (23).

Children’s fish liver oils will also naturally provide some vitamin A and D — as these are stored in fish liver — while other fish oil supplements may have additional vitamin D, A and E. Vitamin E keeps the oil stable and may prolong shelf life.

When purchasing a fish oil supplement for infants or children, try to find ones that are specific for the given life stage to ensure the correct amount of nutrients.

Summary

While there are set recommendations for EPA and DHA for healthy adults, pregnant women — as well as infants and children — have different needs.

To maintain a healthy heart, be sure you’re getting enough EPA and DHA.

Up to 1,000 mg of total EPA and DHA per day is recommended for people who have coronary heart disease and are at risk of having a heart attack (24, 25).

However, a recent review determined that additional EPA and DHA intake, whether through diet or supplements, had little or no effect on reducing the risk of a heart attack (26).

That said, 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 “good” HDL cholesterol.

The higher the intake of EPA and DHA, the greater the effect on 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 mood. Research indicates that supplementing 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 noted that a daily dose of 1,400 mg of combined EPA and DHA reduced symptoms of depression in young adults after three weeks, while another study showed that 2,500 mg of EPA and DHA reduced anxiety in healthy people (32, 33).

In one analysis, omega-3 supplements with higher ratios of EPA to DHA were the most effective in managing depression. Fish oils naturally contain higher ratios (34).

Increasing your intake of omega-3 can also ease inflammation in your body, possibly reducing joint inflammation (35, 36, 37).

However, a review of available studies suggested that EPA and DHA supplements do not consistently benefit people with osteoarthritis (38).

Thus, it is difficult to recommend a specific fish oil or fatty acid dose for joint health.

Even so, in a study in 75 people with knee osteoarthritis, 1,000 mg of fish oil daily — which included 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).

Summary

Fish oil may help reduce triglycerides, improve mood and boost joint health — but dosage recommendations vary depending on the study and the specific health condition.

Fish oil supplements supply EPA and DHA — and many also have vitamins A and D.

Meanwhile, general omega-3 supplements may or may not contain EPA and DHA, depending on whether they are derived from fish, sea algae or plant oils.

If your omega-3 supplement is made from sea algae, it has EPA and DHA. Usually, these supplements are high in DHA and low in EPA (14).

On the other hand, fish oil supplements likely have higher amounts of EPA than DHA, while plant-oil-based supplements give high amounts of ALA.

Although all omega-3s provide benefits, the most beneficial are EPA and DHA (5).

If you do not eat fatty fish regularly, a fish oil supplement may boost your EPA and DHA levels. However, if you don’t consume any fish products, an algae-based supplement is a good alternative.

Otherwise, an omega-3 supplement made from plant oils will help increase your overall intake of omega-3s — but likely won’t raise your EPA or DHA levels.

Summary

Not all omega-3s are equal. While fish oil supplements provide EPA and DHA, most plant sources of omega-3 give ALA — which can be difficult to convert into EPA and DHA.

A vast amount of research supports supplementing with fish oil.

Though there are no conclusive recommendations, 250–500 mg per day of combined EPA and DHA — of which fish oil is an excellent source — is enough for most healthy people.

Keep in mind that this will vary depending on your needs. In addition, pregnant women, infants and children may require different dosages.

If you decide to boost your intake, make sure to choose an omega-3 supplement that contains the recommended amount of EPA and DHA.