Omega-3 fatty acids have many health benefits.
The best way to get them is by eating fatty fish at least twice a week.
If you don't eat fatty fish very often, you should consider taking a supplement.
However, it's important to make sure your supplement contains enough EPA and DHA.
EPA and DHA are the most useful types of omega-3s, and are found in fatty fish and algae.
This article reviews how much omega-3 (combined EPA and DHA) you need for optimal health.
Official Omega-3 Dosage Guidelines
There is no set standard for how much omega-3 you should get each day.
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 (, , , ).
However, higher amounts are often recommended for certain health conditions.
Bottom Line: To date, there is no official recommended daily allowance of omega-3s. However, most health organizations agree that 250–500 mg of combined EPA and DHA is enough for adults to maintain overall health.
Omega-3 for Specific Health Conditions
The following health conditions have been shown to respond to omega-3 supplements.
Here's a quick rundown of the dosages used:
One trial followed 11,000 participants who took an 850-mg dose of combined EPA and DHA every day for 3.5 years. This caused a 25% reduction in heart attacks and a 45% reduction in sudden death ().
Numerous organizations, including the AHA, recommend that patients with coronary heart disease take 1,000 mg. They recommend that patients with high triglycerides take 2,000–4,000 mg of combined EPA and DHA each day (, , , ).
However, several large review studies have not found any beneficial effects of omega-3 fatty acids on heart disease (, ).
Depression and Anxiety
Studies have shown that high doses of omega-3, from 200-2,200 mg per day, can reduce symptoms of depression and anxiety (, , , ).
In the case of mood and mental disorders, a supplement with higher amounts of EPA than DHA may be optimal.
High consumption of fish and omega-3 fatty acids has been linked to a reduced risk of breast, prostate and colon cancers (, , , ).
However, an optimal dosage to reduce the risk of cancer has not been established.
Omega-3 fatty acids can help with numerous other health problems. The effective dosages depend on numerous factors.
Bottom Line: Omega-3 fatty acids can help with numerous health conditions. The dosages shown to be effective range from 200-4,000 mg.
Omega-3 for Children and Pregnant Women
Research shows that omega-3 fatty acids, especially DHA, are vital before, during and after pregnancy (, , , ).
Nearly all official guidelines recommend following adult guidelines and then adding an additional 200 mg of DHA during pregnancy and breastfeeding (, , , ).
Several global and national organizations have published guidelines for infants and children, ranging from 50–100 mg per day of combined EPA and DHA (, ).
Bottom Line: Taking an additional 200 mg of DHA is recommended for pregnant and nursing mothers. The recommended dose for infants and children is 50–100 mg of combined EPA and DHA per day.
Omega-6 Intake May Affect Omega-3 Need
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 (, ).
Many experts believe that this ratio should be closer to 2:1 (omega-6:omega-3) for optimal health ().
Omega-6 and omega-3 fatty acids compete for the same enzymes. These enzymes are needed for the fatty acids to be converted into their active forms (, ).
Therefore, your omega-3 needs may depend on your omega-6 intake. If you consume a lot of omega-6s, you may need even higher amounts of omega-3s.
Bottom Line: The human body may function best with balanced amounts of omega-6 and omega-3. The more omega-6 fatty acids you consume, the more omega-3s you may need.
Too Much Omega-3 Can be Harmful
The FDA has claimed that the use of omega-3s from supplements is safe if doses do not exceed 3,000 mg per day.
On the other hand, the EFSA (European equivalent of the FDA) has declared that up to 5,000 mg per day from supplements is safe.
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 a week or two before the procedure.
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 don't take the risk.
Bottom Line: Taking up to 3,000–5,000 mg of omega-3 per day appears to be safe, although such a high intake is likely not necessary for most people.
Omega-3 Supplement Doses
It's important to read the label of your omega-3 supplement to figure out how much EPA and DHA it actually contains.
This amount varies, and the labels can be confusing. For example, a supplement may say it contains 1,000 mg of fish oil, but in reality actually contains much less than that.
Depending on the concentration of EPA and DHA that is in a dose, you may need to take as many as 8 capsules to reach the recommended amount.
I personally aim for 500 mg of combined EPA and DHA from supplements alone, in as few doses (tablespoons of fish oil or capsules) as possible.
You can find a detailed guide to omega-3 supplements, including which ones to buy, in this article: Omega-3 Supplement Guide: What to Buy and Why.
Bottom Line: It's important consider how much EPA and DHA is in a supplement, not just how much fish oil it contains. This helps ensure you're getting enough EPA and DHA.
Take Home Message
Always follow the instructions on the omega-3 supplement label.
However, keep in mind that different people have different omega-3 needs. Some people may need to take more than others.
Aim for a minimum of 250 mg and a maximum of 3000 mg of combined EPA and DHA per day, unless instructed otherwise by a health professional.