Updated 19th April 2024

Are there benefits to taking krill oil?

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Manufacturers make krill oil from small, shrimp-like creatures called Antarctic krill. The oil is rich in omega-3 fatty acids.

Omega-3s are important for the functioning of our cells, for growth, and for the production of key hormones.

Like fish oil, krill oil contains omega-3s called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

There’s good evidence linking these acids to lower levels of blood fats called triglycerides. They may also help with some health conditions, like rheumatoid arthritis, dementia, and depression.

The best way to get EPA and DHA is by eating enough fish and seafood. These foods also contain other important nutrients, and there’s lots of evidence that they can improve your heart health.

Still, some people may benefit from taking supplements like krill oil. Fish oil supplements tend to be a less expensive alternative.

What are omega-3s, and how might they help?

Most of the potential health benefits of krill oil come from the omega-3s it contains. 

Omega-3s are polyunsaturated fatty acids. They’re part of your cell membranes and are important for healthy growth.

You also need them to produce hormones responsible for blood clotting, artery function, and immune system regulation.

The omega-3s in krill oil are the same as those in fish oil: EPA and DHA. They’re “essential” fatty acids, meaning your body can’t make them, so you have to get them from your diet.

As we mentioned, the best way to take in enough omega-3s is by eating enough fish and other seafood. But krill oil, or other omega-3 supplements, may benefit some people. We’ll dig into this a little later on.

It’s worth noting that a 6-ounce serving of wild-caught salmon, weighing around 170 grams, contains almost as much omega-3 as two 1,000-milligram krill oil capsules.

Next, let’s look at some possible health benefits of getting omega-3s from foods or supplements like krill oil.

Heart health 

While research links eating more fish to having better heart health, one large review of studies found little or no evidence that fish oil supplements lower the risk of heart attack or death from heart disease.

Meanwhile, a large clinical trial with more than 8,000 participants found a link between taking 2-g doses of EPA twice a day and having slightly improved heart health outcomes. The participants were also taking cholesterol-lowering medications called statins.

There’s some evidence that omega-3 supplements in general can lower triglyceride levels. High levels of these fats can increase your risk of heart disease.

A review of 65 studies found that taking daily fish oil omega-3 supplements appeared to lower triglyceride levels in people with normal and high starting levels of these fats.

And a more recent review found that krill oil supplements were about as good at lowering triglycerides as fish oil. 

However, people with high triglyceride levels may also have an increased risk of a heart disorder called atrial fibrillation if they take omega-3 supplements. Atrial fibrillation can, in turn, increase your risk of stroke.

So, omega-3 supplements may only help with triglyceride levels if you take them before your levels get too high.

Krill oil may also have a positive effect on cholesterol levels

One review of seven studies found that krill oil lowered levels of “bad” cholesterol. However, these studies didn’t include many participants, so we need more research to back this up.

Finally, krill oil contains an antioxidant called astaxanthin. Some research links it to raised levels of “good” cholesterol. However, studies tend to look at much bigger doses than those you’ll find in krill oil supplements.

Rheumatoid arthritis 

There’s some early evidence that adding omega-3s to your diet may help ease symptoms of rheumatoid arthritis. 

A small study followed 60 female participants with rheumatoid arthritis for 12 weeks. It found that those who took daily omega-3 supplements had less pain and fewer swollen joints than those who didn’t take the supplements. 

At ZOE, we run the largest nutrition science study in the world, and we know how powerful eating the right foods for your body can be. Learn more about how to achieve your best health by taking our free quiz

Cognitive health 

Researchers reviewing multiple studies found that eating more omega-3s may improve cognitive functions, like focus and memory, and reduce the risk of Alzheimer’s disease.

One large study found that adults aged 60–73 years who regularly took fish oil supplements had a significantly lower risk of developing dementia than those who didn’t take the supplements.

Age-related macular degeneration

Age-related macular degeneration is an eye disease that damages the part of your retina responsible for central vision. 

A review of 21 studies found that people who ate more EPA and DHA had a 14% lower risk of developing an early form of age-related macular degeneration. They also had a 29% lower risk of developing a late form of the condition.


At least two large-scale studies of people’s eating habits have found links between the intake of omega-3s and the risk of developing depression. But the studies arrived at slightly different results. 

One study, involving more than 4,000 women in South Korea who had gone through menopause, found that participants who ate more omega-3s had a significantly lower risk of depression.

Another study looked at people with overweight or obesity in Spain. It found that those eating a moderate amount of omega-3s had a reduced risk of depression. This wasn’t the case for those who consumed a low or high amount of these acids.

Krill oil vs. fish oil

Krill oil comes from small crustaceans, while fish oil comes from the tissues of fatty fish.

Both contain the omega-3s EPA and DHA. Still, there are differences between these supplements:

  • Cost: Krill oil costs more to make than fish oil, so it can be up to 10 times as expensive.  

  • Color: Krill oil has a reddish hue, while fish oil is golden.

  • Composition: Krill oil contains an antioxidant called astaxanthin, which may have benefits for heart health. Fish oil naturally contains more omega-3s. Still, krill and fish oil supplements tend to have the same amounts. 

  • Absorption: Some scientists have suggested that the body can absorb omega-3s from krill more easily. But a review of the research found that krill oil and fish oil supplements had the same effect on levels of fats in blood.

  • Taste and smell: Some people get a fishy aftertaste from fish oil. Fewer people report this with krill oil. 

Should I consider taking it?

Generally, regularly eating fish is the best way to get enough omega-3s. But some people may benefit from taking omega-3 supplements.

Alternatives include fish oil, which is cheaper and just as effective. Vegetarians and vegans can try algal oil, which also contains EPA and DHA.

You might want to think about EPA and DHA supplements if you’re in any of these groups:

  • People who are pregnant or breastfeeding: EPA and DHA are vital for the healthy development of babies. If you’re worried about eating fish while pregnant, you may want to talk to a healthcare provider about a supplement instead.

  • Older adults: As we mention above, studies suggest that regularly taking omega-3 supplements later in life could help reduce the risk of dementia and other age-related diseases.

  • People who don’t eat seafood: A supplement may be the easiest way to get EPA and DHA in this case. Still, having a very healthy plant-based diet is already linked with a lower risk of heart disease, no matter how much EPA and DHA you get.

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Dietary sources of omega-3s

Food is generally the best way to get the omega-3s your body needs.

The heart health benefits of eating fish are much clearer than those linked with taking supplements. Plus, both animal and plant sources of omega-3s come with lots of extra nutrients.

Seafood sources of omega-3s

There are no official recommendations about how much EPA and DHA to get every day.

But the Dietary Guidelines for Americans recommend eating 8 oz (around 227 g) of fish or shellfish every week.  

Here are some options that contain omega-3s:

  • salmon: 1.8 g of omega-3s per 3-oz serving

  • herring: 1.7 g per 3-oz serving

  • mackerel: 1 g per 3-oz serving

  • rainbow trout: 0.8 g per 3-oz serving 

  • oysters: 0.7 g per 3-oz serving

This serving of oysters also contains another type of omega-3: alpha-linolenic acid (ALA).

Plant sources of omega-3

The main omega-3 in plants is ALA. It doesn’t do the same things as EPA and DHA, but it’s also an essential fatty acid with health benefits of its own. 

Experts recommend that adult females get at least 1.1 g of ALA every day and adult males get at least 1.6 g. And if you’re pregnant or breastfeeding, you need more.

The best plant sources of ALA include:

  • flaxseed (linseed) oil: 7.3 g of ALA per tablespoon 

  • chia seeds: 5 g per 1-oz serving

  • walnuts: 2.6 g per 1-oz serving

  • flaxseeds (linseeds): 2.4 g per tablespoon

  • canola (rapeseed) oil: 1.3 g per tablespoon

  • soybean oil: 0.9 g per tablespoon

To start the process of discovering which foods work best for you based on your body’s responses, take our free quiz

Risks and side effects

Doctors consider krill oil and other omega-3 supplements to be safe for most people.

But there are some risks if you use certain medications or have specific health conditions.

These risks include:

  • Drug interactions: Omega-3s can interact with blood-thinning medications, such as warfarin, and nonsteroidal anti-inflammatory drugs, such as ibuprofen. This can cause a cut, for example, to take longer to stop bleeding.

  • Seafood allergies: It’s not clear yet whether krill or fish oil supplements are safe for people with seafood allergies.

  • Atrial fibrillation: People with high triglyceride levels may have a greater likelihood of developing atrial fibrillation, a heart rhythm disorder, if they take omega-3 supplements. This disorder greatly increases your risk of stroke. 

Some people have reported less serious side effects of taking fish oil omega-3 supplements, like:

  • an unpleasant aftertaste or “fishy burps”

  • bad breath

  • bad-smelling sweat

  • a headache

  • digestive issues, such as nausea and diarrhea

But because krill oil is chemically different to fish oil, it’s not clear whether these apply to it.

Frequently asked questions

Many questions remain, but here’s what we know so far.

First, we should note that most of the existing research has looked at omega-3 supplements in general, not krill oil specifically.

Can krill oil help with hair growth?

Good nutrition is key for healthy hair. And some limited evidence suggests that krill oil could help with hair growth.

One small study looked at the effects of supplements containing omega-3s and found significant increases in participants’ hair density and thickness, as well as reduced hair loss.

It’s worth mentioning that this study used a specific omega-3 supplement, so the results may not apply to krill oil. Also, it was funded by Innéov, a group formed by L’Oréal and Nestlé.

Can krill oil help with weight loss?

A review of research was unable to find any consistent results to suggest that omega-3 supplements could help with weight loss or body fat reduction.

Is krill oil good for the skin?

Initial research suggests that the omega-3s and other nutrients in supplements like krill oil may help improve skin health, reduce skin aging due to sun damage, and help with symptoms like dryness.

However, many of these ideas come from animal studies rather than research involving humans.


Krill oil is a food supplement rich in the omega-3s EPA and DHA. It’s similar to fish oil but generally more expensive.

There’s good evidence that regularly consuming omega-3s can reduce your triglyceride levels.

But if a person already has high levels, there are risks associated with taking these supplements.

Omega-3s may also help with health conditions such as rheumatoid arthritis, dementia, and depression.

The best way to get omega-3s is from food. But some of us may benefit from taking a supplement.

People who have atrial fibrillation, take certain medications, or have a seafood allergy should speak with a doctor before taking omega-3 supplements.


5 things to know about omega-3s for heart disease. (n.d.). https://www.nccih.nih.gov/health/tips/things-to-know-about-omegas-for-heart-disease

Advice about eating fish. (2022). https://www.fda.gov/food/consumers/advice-about-eating-fish 

Antioxidant and anti‑inflammatory mechanisms of action of astaxanthin in cardiovascular diseases (review). International Journal of Molecular Medicine. (2020). https://www.spandidos-publications.com/10.3892/ijmm.2020.4783

A reexamination of krill oil bioavailability studies. Lipids in Health and Disease. (2014). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4161905/ 

Association between dietary omega-3 fatty acid intake and depression in postmenopausal women. Nutrition Research and Practice. (2021).  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8313386/ 

Association of fish oil supplementation with risk of incident dementia: A prospective study of 215,083 older adults. Clinical Nutrition. (2022). https://pubmed.ncbi.nlm.nih.gov/35124466/

A systematic review on the role of alpha linolenic acid (ALA) in combating non-communicable diseases (NCDs). Nutrition & Food Science. (2022). https://www.emerald.com/insight/content/doi/10.1108/NFS-01-2022-0023/full/html

Clinical benefits of n-3 PUFA and ɤ-linolenic acid in patients with rheumatoid arthritis. Nutrients. (2017). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5409664/ 

Cosmetic and therapeutic applications of fish oil’s fatty acids on the skin. Marine Drugs. (2018). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6117694/ 

Dietary and supplemental long-chain omega-3 fatty acids as moderators of cognitive impairment and Alzheimer’s disease. European Journal of Nutrition. (2021). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8854294/

Dietary guidelines for Americans, 2020–2025. (2020). https://www.dietaryguidelines.gov/ 

Dietary omega-3 polyunsaturated fatty acids and fish intake and risk of age-related macular degeneration. Clinical Nutrition. (2021). https://pubmed.ncbi.nlm.nih.gov/34749130/

Effect of a nutritional supplement on hair loss in women. Journal of Cosmetic Dermatology. (2015). https://pubmed.ncbi.nlm.nih.gov/25573272/ 

Effects of omega-3 supplementation on body weight and body fat mass: A systematic review. Clinical Nutrition ESPEN. (2021). https://www.sciencedirect.com/science/article/abs/pii/S2405457721001650 

Fish and shellfish. (2022). https://www.nhs.uk/live-well/eat-well/food-types/fish-and-shellfish-nutrition/ 

Fish oil and krill oil supplementations differentially regulate lipid catabolic and synthetic pathways in mice. Nutrition & Metabolism. (2014). https://link.springer.com/article/10.1186/1743-7075-11-20

Lipid-modifying effects of krill oil in humans: Systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews. (2017). https://pubmed.ncbi.nlm.nih.gov/28371906/ 

Lipid-modifying effects of krill oil vs fish oil: A network meta-analysis. Nutrition Reviews. (2020). https://academic.oup.com/nutritionreviews/article/78/9/699/5740623

Nutrition and hair. Clinics in Dermatology. (2021). https://pubmed.ncbi.nlm.nih.gov/34785008/ 

Omega-3 fatty acids. (2022). https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/ 

Omega-3 fatty acids. (2023). https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/

Omega-3 fatty acids and atrial fibrillation. JAMA Network. (2021). https://jamanetwork.com/journals/jama/fullarticle/2777450 

Omega-3 fatty acids and cognitive decline: A systematic review. Nutricion Hospilataria. (2019). https://pubmed.ncbi.nlm.nih.gov/31215788/

Omega-3 fatty acids and pregnancy. Reviews in Obstetrics & Gynecology. (2010). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3046737/

Omega-3 fatty acids: An essential contribution. (n.d.). https://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-and-cholesterol/types-of-fat/omega-3-fats/

Omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid and their mechanisms of action on apolipoprotein B-containing lipoproteins in humans: A review. Lipids in Health and Disease. (2017). https://lipidworld.biomedcentral.com/articles/10.1186/s12944-017-0541-3

Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Library. (2018). https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003177.pub3/full

Omega 3 fatty acids intake does not decrease the risk of rheumatoid arthritis occurrence: A meta-analysis. Comment on Tański et al. The relationship between fatty acids and the development, course and treatment of rheumatoid arthritis. Nutrients. (2022). https://www.mdpi.com/2072-6643/15/3/539

Omega-3 supplementation linked with atrial fibrillation risk: A meta-analysis. Cardiovascular Journal of Africa. (2021). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8756005/ 

Omega-3 supplements: In depth. (2018). https://www.nccih.nih.gov/health/omega3-supplements-in-depth

Seafood consumption, omega-3 fatty acids intake, and life-time prevalence of depression in the PREDIMED-Plus trial. Nutrients. (2018). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6315981/

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