Eicosapentaenoic acid (EPA) is an omega-3 fatty acid that is found along with docosahexaenoic acid (DHA) in cold-water fish, including tuna and salmon.

EPA prevents the blood from clotting easily, reduces triglyceride levels in the blood, and has effects that might reduce pain and swelling.

EPA is a US FDA-approved prescription drug for reducing triglyceride levels. As a supplement, people most commonly use EPA for heart disease, preventing heart attack, and depression. It is also used for chemotherapy-related side effects, diabetes, recovery after surgery, and many other purposes, but there is no good scientific evidence to support many of these other uses.

Don't confuse EPA with similar fatty acids, such as alpha-linolenic acid and DHA. See the separate listings for algal oil, alpha-linolenic acid, DHA, fish oil, and krill oil.

How does it work ?

Uses & Effectiveness ?

Effective for

  • High levels of fats called triglycerides in the blood (hypertriglyceridemia). Taking a prescription drug containing EPA (Vascepa) by mouth lowers triglycerides levels by 33% in people with very high levels. It's not clear if taking EPA supplements has the same effect.

Likely Effective for

  • High levels of blood fats called triglycerides (hypertriglyceridemia). Research shows that taking a specific product containing eicosapentaenoic acid as ethyl eicosapentaenoic acid (Vascepa by Amarin) by mouth along with dieting and cholesterol-lowering drugs called "statins" reduces levels of triglycerides in people with very high levels. It might also improve cholesterol levels. This product is FDA-approved in adults with very high triglyceride levels.

Possibly Effective for

  • Heart disease. Taking a prescription drug containing EPA (Vascepa) by mouth along with statin drugs reduces complications such as heart attack and stroke in people with heart disease. It's not clear if taking EPA supplements helps.
  • Depression. Taking pure EPA or fish oil containing at least 60% EPA by mouth reduces symptoms of depression in some people. It might work best when used along with antidepressant drugs.
  • Heart attack. Taking a prescription drug containing EPA (Vascepa) by mouth along with statin drugs reduces the risk for heart attack in people at risk for heart disease. Taking EPA supplements by mouth also seems to help.
There is interest in using EPA for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: EPA is likely safe when taken as a prescription drug or in fish oil. It's been used safely for up to 7 years. Most side effects are mild and might include nausea, diarrhea, or belching. Taking EPA with meals can reduce these side effects.

EPA is possibly safe when taken as part of an oil from algae (algal oil) for up to 12 weeks. But taking EPA and other omega-3 fatty acids in doses greater than 3 grams daily is possibly unsafe. These higher doses might slow blood clotting and increase the chance of bleeding. Limit intake from supplements to no more than 2 grams daily unless approved by a healthcare provider.

Special Precautions and Warnings

Pregnancy and breast-feeding: There isn't enough reliable information to know if EPA is safe to use when pregnant or breast-feeding. Stay on the safe side and stick to food amounts.

Irregular heartbeat (arrhythmia): EPA might increase the risk of irregular heartbeat. If you have had an irregular heartbeat, talk with your healthcare provider before you start taking EPA.

Aspirin-sensitivity: If you are sensitive to aspirin, EPA might affect your breathing.

Interactions ?

    Moderate Interaction

    Be cautious with this combination

  • Medications for high blood pressure (Antihypertensive drugs) interacts with EICOSAPENTAENOIC ACID (EPA)

    EPA might lower blood pressure. Taking EPA along with medications that lower blood pressure might cause blood pressure to go too low. Monitor your blood pressure closely.

  • Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs) interacts with EICOSAPENTAENOIC ACID (EPA)

    EPA might slow blood clotting. Taking EPA along with medications that also slow blood clotting might increase the risk of bruising and bleeding.


EPA is commonly consumed in the diet. Sources include cold-water fish, including mackerel, herring, tuna, halibut, salmon, cod liver, whale blubber, and seal blubber.

In supplements, EPA has most often been used by adults in doses of 1-2 grams by mouth daily for up to 6 months. Speak with a healthcare provider to find out what dose might be best for a specific condition.
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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version. © Therapeutic Research Faculty 2018.