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Krill Oil (2026): Benefits, Side Effects and Krill vs Fish Oil

Krill oil is an omega-3 supplement made from krill, tiny shellfish. It gives EPA and DHA, the same omega-3s as fish oil, and in trials it lowered triglycerides about as much per gram. If you want krill oil, buy NatureMyst Krill Oil. If you want the most omega-3 for your money, buy fish oil: it costs about a ninth as much per gram.

By Erin Rose Updated October 19, 2026 How we score

What to buy

If you want krill oil: NatureMyst Krill Oil gives the most EPA+DHA of the 7 krill oils we compared, 340 mg in 2 softgels, for $2.65 per gram at the brand’s price. Like the others we link, it is not on a public testing list.

NatureMyst Krill Oil

NatureMyst Krill Oil
Our krill pick · $0.90 a day at the brand’s price

Check price on Amazon

If you want the most omega-3 for your money: buy fish oil. Our fish oil pick, Viva Naturals Triple Strength, gives 2,070 mg of EPA+DHA in 2 softgels for $0.30 per gram.

Viva Naturals Triple Strength

Viva Naturals Triple Strength
Our fish oil pick · $0.30 per gram

See Momentous Omega-3 on Amazon →

Where to go next

  • Best krill oil: all 7 we compared, with EPA+DHA, cost per gram and our score.
  • Best fish oil: every fish oil we score, ranked.
  • Algae omega-3: mostly DHA, if you are allergic to shellfish or eat no fish.

What krill oil does

Krill are small shellfish that live in the ocean around Antarctica. Their oil carries EPA and DHA, the omega-3s in fish oil, mostly bound to fats called phospholipids. What you are buying is the EPA and DHA.

What krill oil trials found for each goal.
GoalEvidenceWhat trials found
TriglyceridesSomeA review of 7 trials (662 people) found triglycerides fell about 14 mg/dL. Per gram of omega-3, krill and fish oil lowered them about the same (review of 64 trials).
LDL cholesterolMixedThe 7-trial review found LDL lower, but in one trial LDL rose on both krill and fish oil.
Knee painMixed, leaning noThe largest trial, 262 people with knee arthritis taking 2 g a day for 24 weeks, found no less pain than placebo (JAMA, 2024). A 235-person trial at 4 g a day found a small gain.
Muscle strength after 65One trialIn 94 adults over 65, 4 g a day for 6 months raised leg strength about 9% and grip about 11% (2022 trial).
Dry eye and memoryToo little dataOne trial each. In 60 people, krill oil eased dry-eye symptoms more than placebo; fish oil improved tear measures about as much (2017 trial); a year of krill oil did not improve thinking tests in 267 teens (2019 trial).
Heart attacksNo krill trialsWe found no trial of krill oil on heart attacks or deaths. In 86 trials of fish-type omega-3, deaths from any cause and total heart and blood vessel events changed little or not at all; coronary heart disease events were about 9% lower, with low-certainty evidence (Cochrane review).

Krill oil vs fish oil

For most people, fish oil is the better buy. It gives far more EPA and DHA per softgel and per dollar, and studies disagree on whether krill absorbs better at the same dose.

Our krill pick vs our fish oil pick, at each brand’s own price.
NatureMyst krill oilViva Naturals Triple Strength fish oil
EPA+DHA in 2 softgels340 mg2,070 mg
Cost per gram of EPA+DHA$2.65$0.30

In the krill oils we compared that print EPA and DHA, a serving gives 74 to 340 mg and costs $2.33 to $5.55 per gram.

Does krill absorb better? At the same dose, trials disagree. A 2026 trial that gave 1.1 g a day of each oil found krill raised blood omega-3 more. A 4-week and a 12-week trial found about the same rise. Even if krill absorbed better, at $2.65 vs $0.30 a gram it would need to work about 9 times as well to cost the same.

How much krill oil to take

Aim for at least 250 mg of EPA+DHA a day, the amount Europe’s food safety agency suggests for adults. Of the krill oils we compared, only NatureMyst and Kori reach that in one serving of 2 softgels; others give as little as 74 mg, so read the EPA and DHA lines, not the krill oil number on the front. Trials gave 2 to 4 g of krill oil a day; at 4 g that was 0.9 to 1.3 g of EPA+DHA (2022 and 2026 trials). The FDA says supplement labels should not suggest more than 2 g of EPA+DHA a day, and it found up to 5 g a day safe (NIH).

Side effects and who should skip it

In the largest trial, side effects were about as common on krill oil as on placebo (51% vs 54%). Check these first:

  • Shellfish allergy: skip krill oil. Krill carry the main shellfish allergen, tropomyosin (2008 study), and a lab study found a protein that looks like it in krill oil products. Fish oil is the safer choice.
  • Blood thinners such as warfarin: ask your doctor. A review of 11 trials with 120,643 people found omega-3 did not raise bleeding overall, though high-dose pure EPA raised it a little.
  • Heart rhythm: in large trials, omega-3 was linked to more atrial fibrillation (an irregular heartbeat): about 12% more at 1 g a day or less, and 49% more above 1 g (2021 review). If you have an irregular heartbeat, ask your doctor.
  • Pregnant or breastfeeding: we found no trial of krill oil’s safety in pregnancy; ask your doctor.

Is krill oil sustainable?

Antarctic krill fishing is the largest and fastest-growing fishery in the Southern Ocean. In 2024, the group that manages it could not agree to renew its catch limits by area, and scientists have called for better management (2025 review). Some brands print an MSC or Friend of the Sea mark for their fishery; those are the brand’s claims.

Questions people ask

How much astaxanthin is in krill oil?

Very little. The krill oils we compare that print it state 17 mcg to 1.5 mg a serving. See our astaxanthin guide for what astaxanthin supplements hold.

Does krill oil go bad?

It can. In a survey of 171 omega-3 products sold in Canada, half were over the voluntary limits for going rancid, and krill oils showed more oxidation than plant-based omega-3s on one test (2015 study). Buy a bottle you will finish before its date.

Sources

  1. Ursoniu S, et al. “Lipid-modifying effects of krill oil in humans: systematic review and meta-analysis of randomized controlled trials.” Nutr Rev. 2017. PubMed 28371906
  2. Kim MG, et al. “Lipid-modifying effects of krill oil vs fish oil: a network meta-analysis.” Nutr Rev. 2020. PubMed 32073633
  3. Ramprasath VR, et al. “Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil.” Lipids Health Dis. 2013. PubMed 24304605
  4. Laslett LL, et al. “Krill Oil for Knee Osteoarthritis: A Randomized Clinical Trial.” JAMA. 2024. PubMed 38776073
  5. Stonehouse W, et al. “Krill oil improved osteoarthritic knee pain in adults with mild to moderate knee osteoarthritis: a 6-month multicenter, randomized, double-blind, placebo-controlled trial.” Am J Clin Nutr. 2022. PubMed 35880828
  6. Alkhedhairi SA, et al. “The effect of krill oil supplementation on skeletal muscle function and size in older adults: A randomised controlled trial.” Clin Nutr. 2022. PubMed 35504165
  7. Deinema LA, et al. “A Randomized, Double-Masked, Placebo-Controlled Clinical Trial of Two Forms of Omega-3 Supplements for Treating Dry Eye Disease.” Ophthalmology. 2017. PubMed 27817918
  8. van der Wurff ISM, et al. “Effect of 1 Year Krill Oil Supplementation on Cognitive Achievement of Dutch Adolescents: A Double-Blind Randomized Controlled Trial.” Nutrients. 2019. PubMed 31151199
  9. Abdelhamid AS, et al. “Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease.” Cochrane Database Syst Rev. 2020. PubMed 32114706
  10. Loukil I, et al. “Krill oil increases plasma omega-3 fatty acids more than fish oil in healthy adults: a double-blind randomized controlled trial.” Am J Clin Nutr. 2026. PubMed 42144109
  11. Yurko-Mauro K, et al. “Similar eicosapentaenoic acid and docosahexaenoic acid plasma levels achieved with fish oil or krill oil in a randomized double-blind four-week bioavailability study.” Lipids Health Dis. 2015. PubMed 26328782
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  13. Tamargo JA, et al. “Pilot Randomized Controlled Trial of Krill Oil Supplementation for Chronic Musculoskeletal Pain in Older Adults.” J Nutr. 2026. PubMed 41933837
  14. Motoyama K, et al. “Identification of tropomyosins as major allergens in antarctic krill and mantis shrimp and their amino acid sequence characteristics.” Mar Biotechnol (NY). 2008. PubMed 18521668
  15. Vang B, et al. “Detection of tropomyosin and determination of proteins in crustacean oils.” Food Chem. 2013. PubMed 23768329
  16. Javaid M, et al. “Bleeding Risk in Patients Receiving Omega-3 Polyunsaturated Fatty Acids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.” J Am Heart Assoc. 2024. PubMed 38742535
  17. Gencer B, et al. “Effect of Long-Term Marine ɷ-3 Fatty Acids Supplementation on the Risk of Atrial Fibrillation in Randomized Controlled Trials of Cardiovascular Outcomes: A Systematic Review and Meta-Analysis.” Circulation. 2021. PubMed 34612056
  18. Meyer B, et al. “Adjusting the management of the Antarctic krill fishery to meet the challenges of the 21st century.” Proc Natl Acad Sci U S A. 2025. PubMed 40920918
  19. Jackowski SA, et al. “Oxidation levels of North American over-the-counter n-3 (omega-3) supplements and the influence of supplement formulation and delivery form on evaluating oxidative safety.” J Nutr Sci. 2015. PubMed 26688721
  20. NIH Office of Dietary Supplements. “Omega-3 Fatty Acids: Fact Sheet for Health Professionals.” ods.od.nih.gov. Labels and prices from each brand’s own page.