Best Fish Oil

Updated May 2021
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BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We only make money if you purchase a product through our links, and all opinions about the products are our own. Read more  
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.Read more 
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How we decided

We purchase every product we review with our own funds — we never accept anything from product manufacturers.

33 Models Considered
16 Hours Researched
3 Experts Interviewed
183 Consumers Consulted
Zero products received from manufacturers.

We purchase every product we review with our own funds — we never accept anything from product manufacturers.

Buying guide for best fish oil

Fish is an excellent source of omega-3s, essential fatty acids that help promote heart health. But not everybody consumes a lot of fish on a regular basis, and doing so can come with its own health problems. That’s where fish oil supplements come in.

Supplements provide the same omega-3 fatty acids in a convenient capsule that you take daily. These have become extremely popular in recent years, but as more and more manufacturers have jumped on the fish oil bandwagon, it’s become harder to pick out the quality fish oil from the subpar imitation. Some unscrupulous manufacturers mislead customers about the amount of omega-3s in their supplements, and some have even been known to put rancid products on store shelves.

BestReviews wants to help you avoid all that. That’s why we’ve put together this shopping guide to help you choose the best fish oil supplement for you. Keep reading to learn what you should really be looking for on that nutrition label.

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Studies suggest that fish oil can help reduce the risk of cancer and degenerative disorders and help keep the brain functioning at an optimal level.

Why take a fish oil supplement?

The omega-3 fats found in fish are essential fatty acids, which means that our bodies cannot make them, so they must be consumed through the diet. These fats have all sorts of beneficial effects on our bodies, including lowering blood pressure and decreasing the risk of heart disease. However, few people today are getting enough omega-3s through diet alone.

Part of the reason is that fish are often contaminated with mercury or other harmful substances, which can cause severe health issues that outweigh the benefits of the fatty acids.

Taking a fish oil supplement is a simple way to add some more omega-3s to your diet if you’re reluctant to consume more fish. These supplements aren’t immune to the contaminants found in fish, but reputable manufacturers make sure that their products are purified before reaching store shelves.

"Some fish oil brands note the source of the oil in the ingredients list."

Fish oil factors to consider


If your fish oil isn’t pure, you could be getting the same contaminants that are often found in fish today. Consuming too much of these can cause a number of health problems, so it’s important to make sure that the fish oil you choose is pure.

Independent testing: You can’t always rely on the manufacturers to be honest about this. That’s why it’s best to go with a product that has been tested by an independent lab for purity and potency. United States Pharmacopeia (USP) and the National Science Foundation (NSF) are two organizations that certify supplements, and you might see one of these seals listed on the product label.

Certificate of analysis: If you don’t see any indication of independent testing on the label, you can ask the manufacturer for the certificate of analysis (COA). This should show the precise ingredients and quantities, as well as any contaminants found in the supplement as verified by an independent lab. If the manufacturer refuses to show you the COA, you might want to choose another product.


Fish oil can do a lot to decrease inflammation in the body, but if the oil is rancid, it can have the opposite effect and even cause more health problems. Stay away from fish oil that smells like a rancid fish. That’s a good indication that the oil has gone bad.

It’s also important to store your fish oil properly in order to keep it from going bad after you’ve purchased it. Read the bottle carefully to see if the fish oil needs to be refrigerated. If not, store it in a cool, dark place. Excessive heat or sunlight might cause the capsules to go bad more quickly.


There are two factors to consider when you’re looking at dosage.

Omega-3s per serving: How many omega-3s are in a single serving? DHA and EPA are the most popular omega-3s, and most fish oil supplements contain both. Most experts recommend a minimum of 500 mg per day, and people who are at risk of heart disease might need to take more. It’s always a good idea to consult with your doctor before taking a fish oil supplement so you can find out which dosage is right for you.

It’s important to check the dosage on the nutrition label rather than the marketing material. Sometimes manufacturers advertise a certain number of milligrams of fish oil – the amount of liquid as a whole – instead of the amount of omega-3s in the supplement.

Number of softgels per serving: The other factor you have to consider when looking at dosage is how many softgels you have to take per serving. It isn’t uncommon for one daily serving to be two or three softgels. The softgels are pretty easy to swallow but might still be a challenge if you have trouble taking pills.


If you’re concerned about the environment, you might want to look for fish oil that has been verified by the Marine Stewardship Council or a similar organization. This tells you that the fish oil has been sustainably sourced and the company doesn’t employ any harmful fishing practices in order to obtain the oil. This type of certification is usually noted on the product label.


Ideally, your fish oil won’t have much of a taste. A common problem with taking fish oil supplements is they cause fishy-tasting burps. Unfortunately, there isn’t an easy way to avoid this. The best you can do is read customer reviews to see how much of a problem this is with the supplement you’re considering.

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Did you know?
Some fish oil supplements might also contain omega-6 or omega-9 fatty acids, but these aren’t as crucial because they’re much more common in the average American diet than omega-3s.

Fish oil prices

When choosing fish oil supplements, you want to pay attention to the price per daily serving as opposed to the overall price. It’s important not to confuse price per serving with price per softgel. You often have to take more than one softgel to get the full daily serving of omega-3s.

Most fish oil supplements range from about $0.20 to $0.50 per serving, with most falling around $0.38 per serving. As with most supplements, a higher price is not necessarily an indication of a better product.

It’s important to consider the price along with the other factors mentioned above to make sure you’re getting a high-quality product that will give you the health benefits you want without the side effects you don’t.

"The best fish oil goes through some type of distillation process to remove any heavy metals or contaminants from the product."


  • Start small. You might want to begin with a single softgel per day, regardless of the stated serving size, and work up from there. Taking too much fish oil when your body isn’t used to it can cause gastrointestinal problems.

  • Take fish oil with meals. Taking your fish oil supplements with food can reduce the likelihood of fishy burps later.

  • Try liquid supplements. If you struggle with taking pills, look for a liquid fish oil supplement instead.

  • Freeze the fish oil. Some say that freezing fish oil supplements helps to minimize any undesirable side effects.
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Sardines, mackerel, and anchovies are the most common sources of fish oil.


Q. Are there any side effects to taking fish oil?

A. Some people experience mild diarrhea and stomach discomfort when they first begin taking fish oil. If this happens to you, it’s a good idea to back off a little until your body adjusts to it and then increase the dosage again. The side effects should go away once your body is accustomed to the fish oil. If not, visit your doctor.

Q. Is it safe to consume fish oil during pregnancy?
A. Yes. In fact, many prenatal vitamins have some DHA and EPA in them. These omega-3s can help your baby’s neural development and may help protect against certain health conditions. As always, it’s important to make sure that the fish oil you choose is pure and doesn’t contain any heavy metals or other contaminants that could be harmful to your baby.

Q. Is krill oil the same as fish oil?

A. Krill oil shares some of the benefits of fish oil, but it is derived from small crustaceans instead of fatty fish. Like fish oil, krill oil is high in omega-3s and can help promote heart health and reduce inflammation within the body.

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