Omega-3 fatty acids have many health benefits. The best way to reap them is by eating fatty fish at least twice per week, but if you don’t eat fatty fish often, you should consider taking a supplement.

It’s important to make sure your supplement contains enough eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These are the most useful types of omega-3 fats, and they are found in fatty fish and algae.

You can also get omega-3 from seeds and nuts, like flax seeds and walnuts. These foods contain alpha-linolenic acid (ALA), a small part of which can be converted into EPA and DHA in your body (1).

This article reviews how much omega-3 you need for optimal health.

Various mainstream health organizations have released their own expert opinions, but they vary considerably.

Overall, most of these organizations recommend a minimum of 250–500 mg combined EPA and DHA each day for healthy adults. This can be obtained from about 8 ounces of fatty fish per week (2, 3, 4, 5).

However, higher amounts are often recommended for certain health conditions.

The recommended dietary allowance (RDA) for alpha-linolenic acid is 1.6 grams per day for men and 1.1 grams per day for women (6).


To date, there is no official recommended daily allowance for EPA and DHA. However, most health organizations agree that 250–500 mg of combined EPA and DHA is enough for adults to maintain their overall health.

The following health conditions have been shown to respond to omega-3 supplements.

Heart disease

One study followed 11,000 people who took an 850-mg dose of combined EPA and DHA every day for 3.5 years. They experienced a 25% reduction in heart attacks and a 45% reduction in sudden death (7).

The American Heart Association (AHA) recommends that people with coronary heart disease or heart failure take omega-3 supplements containing EPA and DHA daily. More research is needed to establish the ideal dose, but most studies have used about 1,000 mg per day. For people with high triglycerides, the AHA recommends a dose of 4,000 mg per day (8, 9, 10).

However, some large studies have not supported the use of omega-3 supplements to reduce the risk of heart disease. This topic is still being investigated (11, 12).

Overall, evidence is stronger for the benefits of omega-3 supplements in people with a history of heart disease rather than generally healthy people (13).

Depression and anxiety

Studies suggest that high doses of omega-3, ranging from 200–2,200 mg per day, can reduce symptoms of depression and anxiety (14, 15, 16).

In cases of mood and mental disorders, a supplement with higher amounts of EPA is more likely to have a beneficial effect than one with higher DHA.

However, some research suggests that omega-3 supplements had little or no effect in preventing depression or anxiety symptoms. More research is needed (17).


A high intake of fish and omega-3 fatty acids has been linked to a reduced risk of breast, prostate, and colon cancers (18, 19).

However, correlation doesn’t equal causation. Controlled studies need to confirm whether your intake of omega-3 fatty acids affects your cancer risk.


Omega-3 fatty acids may relieve several health conditions. An effective dosage ranges from 200–4,000 mg.

Research shows that omega-3 fatty acids, especially DHA, are vital before, during, and after pregnancy (20, 21, 22, 23).

Nearly all official guidelines recommend adding 8–12 ounces of fish or shellfish per week during pregnancy and nursing, or an extra 200–300 mg of DHA per day (24, 25, 26).

The FDA suggests 2 servings of fish or seafood per week for children. Serving size depends on age (25):

  • 1 ounce at ages 1–3
  • 2 ounces at ages 4–7
  • 3 ounces at ages 8–10
  • 4 ounces at age 11 and up

Additionally, the FDA also recommends low-mercury seafood options for children and pregnant people (25).


An additional 200–300 mg of DHA is recommended during pregnancy and nursing. The recommended serving for children depends on their age.

The typical Western diet contains around 10 times more omega-6s than omega-3s. These omega-6 fatty acids come mainly from refined vegetable oils that are added to processed food (27, 28).

Many experts believe that the optimal omega-6 to omega-3 ratio is closer to 2:1 (29).

Omega-6s and omega-3s compete for the same enzymes, which convert the fatty acids into their biologically active forms (30, 31).

Therefore, if you wish to improve your omega-3 status, you should not only be sure to get enough omega-3 from your diet and supplements but also consider reducing your intake of vegetable oils high in omega-6.


Your body may function best with balanced amounts of omega-6 and omega-3.

The FDA and the European Food Safety Authority (EFSA) claim that omega-3 supplements containing EPA and DHA are safe if doses don’t exceed 5,000 mg per day (13, 32, 33).

These cautions are in place for several reasons. For one, omega-3s can cause blood thinning or excessive bleeding in some people.

For this reason, many organizations encourage people who are planning surgery to stop taking omega-3 supplements 1–2 weeks beforehand.

The second reason is due to vitamin A. This vitamin can be toxic in high amounts, and some omega-3 supplements, such as cod liver oil, are high in it.

Finally, taking more than 5,000 mg of omega-3s has never been shown to provide any added benefits, so the risk is not worth taking.


Taking up to 5,000 mg of omega-3 per day appears to be safe, although such a high intake is likely not necessary for most people.

Omega-3 supplements, including fish oil, contain the long-chain omega-3 fatty acids EPA and DHA.

It’s important to read the label of your omega-3 supplement to figure out how much EPA and DHA it contains.

These amounts vary, and the labels can be confusing. For example, a product may provide 1,000 mg of fish oil, but its levels of these two fats could be much lower.

Depending on the concentration of EPA and DHA in a dose, you may need to take as many as eight capsules to reach the recommended amount.

For more information, you can consult this detailed guide to omega-3 supplements.


It’s important to consider how much EPA and DHA there is in a supplement — not just how much fish oil it contains. This helps ensure that you’re getting enough EPA and DHA.

When taking omega-3 supplements, always follow the instructions on the label.

However, keep in mind that omega-3 needs vary by individual. Some people may need to take more than others.

The recommended intake of alpha-linolenic acid is 1.6 grams per day for men and 1 gram per day for women.

In contrast, there are no official guidelines for the intake of long-chain omega-3s. Yet, health organizations generally recommend a minimum of 250 mg and a maximum of 4,000 mg — and no more than 5,000 mg — of combined EPA and DHA per day, unless instructed otherwise by a health professional.