Skip navigation

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

URL of this page: https://medlineplus.gov/druginfo/meds/a607065.html

Omega-3 Fatty Acids

pronounced as (oh may' ga)

Why is this medication prescribed?

Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat-like substance) in the blood in people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic or lipid-regulating agents. Omega-3 fatty acids may work by decreasing the amount of triglycerides and other fats made in the liver.

How should this medicine be used?

Prescription omega-3 fatty acids such as omega-3-acid ethyl esters (Lovaza, Omytrg), icosapent ethyl esters (Vascepa), and omega-3-carboxylic acids (Epanova) come as a liquid filled gel capsule to take by mouth. Epanova is usually taken once daily with or without food. Lovaza is usually taken one or two times a day with or without food. Omytrg is usually taken one or two times a day with food. Vascepa is usually taken two times a day with food. Nonprescription omega-3 fatty acids come as gel capsules to take by mouth as directed on the package label. Take omega-3 fatty acids at around the same time(s) every day. Follow the directions on your prescription label or on the package carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take omega-3 fatty acids exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the capsules whole; do not split, crush, chew, or dissolve them. If you cannot swallow capsules whole, tell your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before taking omega-3 fatty acids,

  • tell your doctor and pharmacist if you are allergic to omega-3 fatty acids including omega-3-acid ethyl esters, icosapent ethyl esters, and omega-3-carboxylic acids; fish, including shellfish (clams, scallops, shrimp, lobster, crayfish, crab, oyster, mussels, others); any other medications; or any of the ingredients in omega-3 fatty acid capsules. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin, Jantoven); antiplatelet medications such as cilostazol (Pletal), clopidrogrel (Plavix), dipyridamole (Persantine, in Aggrenox), prasugrel (Effient), and ticlopidine; beta-blockers such as atenolol (Tenormin, in Tenoretic), labetalol (Trandate), metoprolol (Lopressor, Toprol XL, in Dutoprol), nadolol (Corgard, in Corzide), and propranolol (Inderal, Innopran XL, in Inderide); diuretics ('water pills'); estrogen-containing contraceptives (birth control pills, patches, rings, and injections); and estrogen replacement therapy. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have diabetes, atrial fibrillation or atrial flutter (conditions in which the heart beats irregularly); or liver, thyroid, or pancreatic disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking omega-3 fatty acids, call your doctor.
  • ask your doctor about the use of alcoholic beverages while you are taking omega-3- fatty acids.

What special dietary instructions should I follow?

Eat a low-fat, low-cholesterol diet. Be sure to follow all exercise and dietary recommendations made by your doctor or dietitian. You can also visit the National Cholesterol Education Program (NCEP) website for additional dietary information at http://www.nhlbi.nih.gov/health/public/heart/chol/chol_tlc.pdf.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Omega-3 fatty acids may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • burping
  • heartburn
  • stomach pain or discomfort
  • joint pain
  • vomiting
  • constipation
  • diarrhea
  • nausea
  • change in the sense of taste

Omega-3 fatty acids may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Do not freeze.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

In case of emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to omega-3 fatty acids.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking omega-3 fatty acids.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Epanova®
  • Lovaza® (formerly available as Omacor®)
  • Omtryg®
  • Vascepa®
Last Revised - 08/15/2016