Omega-3-Acid Ethyl Esters (Oral)

When used alongside diet and lifestyle changes, omega-3-acid ethyl esters work to reduce the production of triglycerides in order to control hypertriglyceridemia.


Omega-3-acid ethyl esters are used in combination with lifestyle changes to reduce high levels of triglycerides in the blood (hypertriglyceridemia). If left untreated, high triglyceride levels can lead to nausea and vomiting, pain in the abdomen, chest or back, labored breathing, a skin condition called xanthomas, and eye problems.

Designed to be taken over a long period of time, omega-3-acid ethyl esters work on the liver to reduce the amount of triglycerides and other fatty substances that are produced. However, the medicine only helps to control hypertriglyceridemia and is most effective when patients take steps to naturally reduce triglyceride levels. Adopting a low-fat, balanced diet, losing excess weight, and exercising regularly are tactics commonly recommended by doctors.

In the US, omega-3-acid ethyl esters are only available with a doctor's prescription. They are provided in liquid-filled capsules which should be taken orally and are known under the brand names Lovaza and Omtryg.

Conditions Treated?

  • Hypertriglyceridemia

Type Of Medicine?

  • Antihyperlipidemic

Side Effects

Sometimes omega-3-acid ethyl esters can cause unwanted side effects as well as its needed effects. Not all of these effects are serious, but some are and require medical attention. Be sure to familiarize yourself with all side effects in order that you can recognize when to report harmful effects to your doctor.

The following side effects are serious and require immediate medical attention:

  • Rapid or irregular heartbeat
  • Tightness in chest
  • Difficulty breathing
  • Difficulty swallowing
  • Cough
  • Coughing blood
  • Bleeding gums
  • Nosebleeds
  • Prolonged bleeding from cuts
  • Increased vaginal bleeding or menstrual flow
  • Hives, skin rash, or itching
  • Swelling or puffiness of eyelids, face, lips or tongue
  • Dizziness
  • Paralysis
  • Unusual tiredness or weakness
  • Sweating
  • Red or black, tarry stools
  • Red or dark brown urine

The following side effects are usually minor and don't require medical attention unless they become severe or prolonged. They may dissipate as your body adjusts to the medicine. If you have questions about them, consult your doctor who may be able to recommend lifestyle changes to reduce their severity or prevent them.

  • Acidic or sour stomach
  • Excess air or gas in stomach
  • Bloating or feeling full
  • Belching
  • Passing gas
  • Heartburn
  • Indigestion
  • Stomach discomfort, pain, or upset
  • Change in taste
  • Bad or unpleasant aftertaste
  • Loss of appetite
  • Nausea or vomiting
  • Diarrhea
  • Difficulty passing stools

This may not be an exhaustive list of all side effects that omega-3-acid ethyl esters can cause. If you notice other effects not listed here, consult your doctor as soon as possible. You could also report them to the FDA.


The amount of omega-3-acid ethyl esters you take may vary depending on the severity of your condition and other factors personal to you and your medical history. Always follow your doctor's instructions, and do not take more or less omega-3-acid ethyl esters than is prescribed to you. The frequency at which you take the medicine may depend on the brand of omega-3-acid ethyl esters that you are prescribed.

On average, most adults take four capsules each day. Your doctor may tell you to take all four capsules in a single dose, or divide them into two doses of two capsules.

The capsules should be swallowed whole without crushing, chewing, breaking or dissolving. If you have trouble swallowing them whole, ask your doctor for advice. You can take them with food if you wish. It is advised that you take each dose at around the same time every day.

If you miss a dose of omega-3-acid ethyl esters, take it as soon as you remember as long as it is not almost time for your next dose. In this case, simply skip the missed dose and continue with your original dosing schedule. Do not double doses of omega-3-acid ethyl esters, as this could increase the risk or severity of side effects.

Importance of lifestyle changes

It's important to note that omega-3-acid ethyl esters only help to manage high triglyceride levels. If blood tests confirm that your triglyceride levels have reduced, this does not mean you can stop taking the medicine. If you do so, triglyceride levels may increase again. To better manage triglyceride levels, it's important to follow your doctor's advice in regard to lifestyle changes. In many instances, your doctor may prescribe lifestyle changes before they prescribe omega-3-acid ethyl esters.

The most common changes that doctors recommend are related to diet. They may provide you with a special diet which is low in fat, sugar, and cholesterol. You may be referred to a dietitian or nutritionist if you find you are struggling to adopt the new diet.

Exercise is also frequently recommended to people with hypertriglyceridemia, but be sure to check with your doctor before adopting a new fitness routine so that they can check the activities you plan to take up are safe for you. Generally, it is better to gradually increase your activity level as you become fitter.

Omega-3-acid ethyl esters may be less effective in people who are very overweight. Your doctor may request that you lose weight before they prescribe omega-3-acid ethyl esters, or when you first begin taking them. Always consult your doctor before adopting a weight-reducing diet. Again, a dietitian or nutritionist may be able to help you adopt a healthy, balanced diet that will aid weight loss.


Omega-3-acid ethyl esters can interact with other medicines. It is vital that you tell your doctor about all the medicines you take, including those prescribed to you, those purchased over the counter, and any multivitamins or herbal supplements that you take. They will be able to check for harmful interactions.

Where interactions do occur, your doctor may avoid prescribing omega-3-acid ethyl esters or they may change some of the medicines you already take. If both drugs are deemed important, they might adjust dosages of your existing medicines or give you new instructions as to the times of day at which to take all your medicines. Always follow your doctor's directions closely.

It is particularly important to tell your doctor about the following medicines:

  • Anticoagulants ('blood thinners'), such as:

O Warfarin (Coumadin, Jantoven)

  • Antiplatelet medications, such as:

O Cilostazol (Pletal)

O Clopidrogrel (Plavix)

O Dipyridamole (Persantine, in Aggrenox)

O Prasugrel (Effient)

O Ticlopidine

  • Beta-blockers, such as:

O Atenolol (Tenormin, in Tenoretic)

O Labetalol (Trandate)

O Metoprolol (Lopressor, Toprol XL, in Dutoprol)

O Nadolol (Corgard, in Corzide)

O Propranolol (Inderal, Innopran XL, in Inderide)

  • Diuretics ('water pills')
  • Estrogen-containing contraceptives, including:

O Pills

O Patches

O Rings

O Injections

  • Estrogen replacement therapy.



Tell your doctor about all allergies you suffer from, including food, pollen, chemical and drug allergies. You may not be able to take omega-3-acid ethyl esters if you allergic to any of the ingredients in the capsules. It is particularly important to mention the following allergies:

  • Omega-3-acid ethyl esters
  • Omega-3-carboxylic acids
  • Icosapent ethyl esters
  • Fish, including shellfish

Interactions With Medical Conditions

Some pre-existing medical conditions can interact with the use of omega-3-acid ethyl esters and cause serious health problems. Make sure your doctor is aware of your full medical history before you start taking the drug.

In people with atrial fibrillation or flutter, which is a heart rhythm problem, or a history of the condition, omega-3-acid ethyl esters could make it worse or cause it to return.

People with liver problems, such as liver disease or cirrhosis, may be at a higher risk of developing serious side effects when taking omega-3-acid ethyl esters. Depending on the severity of the liver problem, your doctor may continue to prescribe omega-3-acid ethyl esters but request closer monitoring of your condition.

Both diabetes and hypothyroidism (underactive thyroid) can increase the risk of hypertriglyceridemia. Your doctor may try to better control these conditions before they prescribe omega-3-acid ethyl esters.

Pregnancy and breastfeeding

Animal studies have demonstrated that omega-3-acid ethyl esters can cause adverse effects to the fetus, and there are not enough well-controlled human studies to determine fetal risks. For this reason, use of the drug during pregnancy should be reserved for instances in which the benefits to the mother far outweigh potential risks to the fetus.

Omega-3-acid ethyl esters are excreted in human breast milk, but the effects they may have on nursing infants is unknown. The drug should, therefore, be used with caution in breastfeeding women. It may be safer to avoid breastfeeding if possible.

Pediatric use

The efficacy and safety of omega-3-acid ethyl esters in children is unknown. For this reason, use of the drug is determined by doctors on a case by case basis.


Store omega-3-acid ethyl esters in the container they were provided in, with the lid tightly closed at all times, at room temperature. Do not allow the medicine to freeze, and keep it away from heat, direct light and moisture. Store the capsules out of reach and sight of children.

If you have leftover or expired omega-3-acid ethyl esters, do not keep them. Instead, ask your healthcare provider how to safely dispose of them. There may be a local medicine take-back program you could use to ensure they are disposed of without causing harm to others or the environment. Do not simply flush the capsules down the toilet or throw them in the trash.


Omega-3-acid ethyl esters capsules are designed to help control hypertriglyceridemia (high levels of triglycerides in the blood). The medicine is most effective when used alongside lifestyle changes, such as weight loss, adopting a diet low in sugar, fat, and cholesterol, and exercising more regularly. Designed to be taken by mouth, the medicine should be taken every day over a long period of time.

It is common to experience indigestion, sour stomach, increased bloating and gas, and changes in taste when taking omega-3-acid ethyl esters. However, these effects do not usually require medical attention unless they become very severe. If patients experience bleeding problems, difficulty breathing, blood in stools or urine, or skin rash, hives or swelling, they should consult their doctor immediately.

Patients should make sure their doctor knows if they are taking anticoagulants, antiplatelet medicines, beta-blockers, diuretics, or contraceptives or hormone replacement medicines which contain estrogen. The drug may not be suitable for patients with allergy to fish or shellfish. Use in pregnant women is not advised, and people with diabetes, hypothyroidism, liver problems, or heart rhythm problems may not be able to take the medicine or may require closer monitoring.