Omega-3 Fish Oil Supplements and Prescriptions

Your doctor may have suggested that you eat non-fried salmon or other fatty fish at least twice a week. The reason for this recommendation is that some fish are high in omega-3 fatty acids. These are healthy fats that have been promoted for a variety of heart, brain, and other health benefits.

Your body can't make omega-3 fatty acids. So you need to get them from your diet. The ideal sources are from foods like:

  • Fatty fish such as anchovies, salmon, mackerel, herring, sardines, trout, and tuna (bluefin and albacore),
  • Flaxseeds
  • Nuts, especially walnuts

Even though food should be your main source of omega-3 fatty acids, most Americans don't get enough of this nutrient from diet alone.

If that's the case with you, your first step should be to eat more fish and other omega-3 foods. Besides providing omega-3s, these foods have other health benefits, including:

  • Proteins
  • Vitamins
  • Minerals

Types of Omega-3 Fatty Acids

There are three main types of omega-3 fatty acids:

EPA. This type of omega-3 is found primarily in:

  • Fish
  • Fortified foods, such as some brands of eggs and orange juice
  • Fish oil supplements you can buy without a prescription
  • Prescription fish oil

EPA helps lessen inflammation in the body.

DHA. This type is found in:

  • Fish
  • Fortified foods, such as some brands of eggs and orange juice
  • Fish oil supplements you can buy without a prescription
  • Prescription fish oil
  • Algae supplements

DHA is essential for brain health and function.

ALA. This is contained in walnuts, chia seeds, and flaxseeds. It's also found in vegetable oils such as:

The body converts ALA to its more active forms -- EPA and DHA -- but only in small amounts.

Non-Prescription Omega-3s and Your Health

When it comes to preventing or treating disease, many studies have not found much benefit in taking low daily doses of omega-3 supplements. Only prescription-strength omega-3 has been found to have health benefits.

Prescription Omega-3s and Your Health

Prescription fish oil capsules contain a higher dose of omega-3 fatty acids than non-prescription versions. They are also monitored by the FDA for quality and safety.


Your doctor will probably only recommended prescription-strength fish oil if your triglycerides are very high (more than 500 mg/dL).

Research suggests very high triglyceride levels are linked to an increased risk of heart disease and stroke. However, more research is needed to determine if prescription omega-3s lower the risk of cardiovascular disease.

Very high triglycerides are also linked to pancreatitis.

These are some of the prescription-strength omega-3 fatty acids that are available:

  • Epanova (omega-3-carboxylic acids). This contains a combination of EPA and DHA.
  • Lovaza (omega-3-acid ethyl esters). This contains a combination of EPA and DHA.
  • Omtryg: (omega-3-acid ethyl esters). This contains a combination of EPA and DHA.
  • Vascepa (icosapent ethyl). This contains EPA only.

Side Effects of Non-Prescription Omega-3s

The FDA doesn't regulate supplements as closely as prescriptions. So the amount of omega-3s listed on the label may be higher than what you actually get. In addition, supplements may not be pure omega-3s and may contain other ingredients or contaminants.

Non-prescription omega-3 fatty acid supplements may cause mild side effects, such as:

Talk to your doctor before taking omega-3 supplements if you:

Side Effects of Prescription Omega-3s

Common side effects of prescription omega-3s vary according to the type of prescription.

Side effects of Epanova may include:

Side effects of Lovaza and Omtryg may include:

Joint pain may be a side effect of Vascepa.

Prescription omega-3 fatty acids or high doses of omega-3 supplements may also affect the blood's ability to clot. People who take blood-thinning medications should be aware of this precaution if they also take omega-3s. Talk to your doctor if you take blood thinning medicines, such as warfarin (Coumadin) or nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen (Advil or Motrin),.

Omega-3 fatty acids lower high triglyceride levels, but brands that contain DHA may raise levels of LDL "bad" cholesterol. This could be a problem if you also have high cholesterol, which often goes hand-in-hand with high triglycerides.

WebMD Medical Reference Reviewed by Melinda Ratini, DO, MS on May 29, 2019



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