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Omega-3 Supplement

Krill Oil — Research Profile

Evidence:Moderate
·

This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Krill oil supplies EPA and DHA, partly in phospholipids.

Krill oil supplies EPA and DHA, partly in phospholipids. Studies do not establish a universal 68% absorption advantage or better clinical outcomes than fish oil. Compare actual EPA+DHA content, not grams of oil. Lipid changes and limited PMS studies do not prove cardiovascular-event prevention.

Krill oil is an EPA/DHA source, with no established overall clinical superiority to fish oil. Compare active omega-3 content, tolerance, cost and allergy considerations.

Evidence:RCT (2011) · n=113 · moderate confidence[#1]. See full reference list below.

Key Facts

What it is
A marine omega-3 supplement from Antarctic krill (Euphausia superba) providing EPA and DHA in phospholipid-bound form with natural astaxanthin
Primary benefits
  • An EPA/DHA source with some lipid-outcome evidence
  • Limited preparation-specific research in PMS and joint symptoms
  • No established superior cardiovascular protection versus fish oil
Typical dosage
Study regimens vary; read both oil weight and actual EPA+DHA per serving
Evidence level
Moderate
Safety profile
Generally Safe

Time to Effect

Hours
Days
Weeks
Months
2-12 weekstypical onset

Inflammatory markers (CRP) may improve within 2-4 weeks. Cholesterol and triglyceride changes typically require 8-12 weeks. PMS benefits observed within 1-3 menstrual cycles. Consistent daily use required for cumulative membrane incorporation.

What the Research Says

Ulven et al. (2011) compared 3 g/day krill oil supplying 543 mg EPA+DHA with 1.8 g/day fish oil supplying 864 mg EPA+DHA, and a no-supplement group, in 113 adults. Both oils increased plasma omega-3 levels, with no significant between-oil difference. Serum lipids and inflammatory markers did not significantly differ among groups. The study did not demonstrate 68% greater red-cell incorporation at matched doses.

A 2020 network meta-analysis of 64 trials found no significant lipid-effect difference between krill and fish oil; triglyceride reduction depended on omega-3 dose. Other krill-oil reviews report some lipid changes, but laboratory lipid changes do not prove fewer cardiovascular events.

A small PMS trial compared krill oil with fish oil, without placebo. Joint-outcome reviews have mixed findings. These condition-specific results do not establish a universal 1–3 g therapeutic regimen or clinical superiority from the phospholipid form.

Benefits of Krill Oil

  • Omega-3 delivery — Ulven et al. (2011) randomized 113 adults to krill oil, fish oil or no supplement. Plasma omega-3 increases did not differ significantly between oil groups, despite different EPA+DHA doses.
  • Lipids — a 64-trial network meta-analysis found no significant difference between krill and fish oil in lipid effects; triglyceride changes depended on omega-3 dose.
  • PMS — a 70-woman trial compared krill oil with fish oil for three cycles and reported symptom differences. It did not include a placebo group.
  • Joint symptoms — recent reviews differ across pain and function outcomes. This is not a settled treatment effect for all arthritis populations.
  • Product stability — astaxanthin is present, but does not guarantee a product cannot oxidize or cause an unpleasant aftertaste.

Our Top Krill Oil Picks

As an Amazon Associate, we earn from qualifying purchases. Some links below are affiliate links — this doesn't affect our editorial independence or product ratings. How we evaluate products

Sports Research Antarctic Krill Oil 1000mg
Sports Research Antarctic Krill Oil 1000mg
Sports Research
#1 Top Pick
OverallForm: SoftgelPrice: $30.95 · $0.52 / count
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NOW Supplements Neptune Krill Oil 500mg
NOW Supplements Neptune Krill Oil 500mg
NOW Foods
Budget / ValueForm: SoftgelPrice: $31.95 · $0.27 / count
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Viva Naturals Antarctic Krill Oil 1250mg
Viva Naturals Antarctic Krill Oil 1250mg
Viva Naturals
Highest AstaxanthinForm: SoftgelPrice: $29.93 · $0.50 / count
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Dr. Mercola Antarctic Krill Oil 1000mg
Dr. Mercola Antarctic Krill Oil 1000mg
Dr. Mercola
Most SustainableForm: CapsulePrice: $31.99 · $0.53 / count
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MegaRed Ultra Strength Krill Oil 1000mg
MegaRed Ultra Strength Krill Oil 1000mg
MegaRed
Most Trusted BrandForm: SoftgelPrice: $29.97 · $0.50 / count
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See all krill oil products →
Did you know?

Ulven et al.

Forms of Krill Oil

Krill Oil supplement forms compared by bioavailability and best use
FormBioavailabilityBest For
Softgels (Phospholipid Complex)HighStandard supplementation — most common and convenient form; phospholipid matrix disperses in stomach acid for rapid absorption without requiring bile salts
Liquid Krill OilHighFlexible dosing — rare form for those who cannot swallow softgels; requires refrigeration and has shorter shelf life

Dosage Recommendations

General recommendation: Compare the labeled EPA+DHA amount as well as total krill-oil weight. Research regimens vary by product and outcome; no universal therapeutic dose.

Timing: With breakfast or lunch for best absorption; evening dosing acceptable but may cause mild GI discomfort if taken on an empty stomach • Take with food for best absorption.

Dosage by Condition

General cardiovascular support
1g dailyModerate
High cholesterol / triglyceride reduction
2-3g dailyModerate
PMS symptom relief
2g dailyModerate
Joint inflammation / arthritis
300mg-2g dailyEmerging
General omega-3 maintenance
1-2g daily (250-500mg combined EPA+DHA)Moderate

Upper limit: No established krill-oil upper intake level. 4 g of krill oil is not equivalent to 4 g EPA+DHA.

Medication Interactions & Contraindications

Drug Interactions

blood-thinners
moderate
blood-thinners
Krill oil omega-3s have antiplatelet activity that may potentiate warfarin's anticoagulant effect. Monitor INR more frequently when starting or changing krill oil doses. Discuss with prescribing physician before combining.
blood-pressure-medication
minor
blood-pressure-medication
Krill oil may modestly lower blood pressure (2-3 mmHg). Monitor for dizziness or hypotension symptoms, especially when initiating krill oil alongside blood pressure medications.
orlistat
minor
orlistat
Orlistat blocks fat absorption and may reduce krill oil omega-3 uptake. Separate krill oil and orlistat doses by at least 2 hours for optimal absorption.

Who Should NOT Take This

Shellfish or crustacean allergy(absolute)
Krill are crustaceans (order Euphausiacea). Individuals with confirmed shellfish or crustacean allergies must avoid krill oil entirely due to risk of anaphylaxis. This is a true allergy contraindication — no safe dose exists.
Bleeding disorders (hemophilia, von Willebrand disease)(relative)
Omega-3 fatty acids have antiplatelet activity that may exacerbate bleeding disorders. Use only under medical supervision with regular coagulation monitoring.
Upcoming surgery (within 2 weeks)(relative)
Discontinue krill oil at least 2 weeks before scheduled surgery due to antiplatelet effects that may increase intraoperative and postoperative bleeding risk. Resume after surgical wound has healed and with surgeon's approval.

This information is for educational purposes only. Always consult your healthcare provider before starting or stopping any supplement, especially if you take prescription medications.

Side Effects and Safety

Safety profile: Generally Safe

Potential Side Effects

  • Gastrointestinal symptoms and unpleasant aftertaste can occur; phospholipids or astaxanthin do not guarantee their absence.
  • Krill are crustaceans; shellfish allergy warrants avoidance unless an allergy clinician specifically advises otherwise.
  • Discuss concentrated omega-3 use with a clinician when taking anticoagulants or managing a medical condition.

Drug & Supplement Interactions

  • Anticoagulants and antiplatelets (warfarin, heparin, aspirin, clopidogrel) — omega-3s have additive antiplatelet effects; may increase bleeding risk
  • Antihypertensive medications — krill oil may modestly lower blood pressure; monitor for additive hypotension
  • Orlistat (weight loss medication) — may reduce absorption of fat-soluble nutrients including krill oil omega-3s; separate doses by 2+ hours
  • Other omega-3 supplements — additive effects; total EPA+DHA intake should be considered

Do not exceed: No established krill-oil upper intake level. 4 g of krill oil is not equivalent to 4 g EPA+DHA.

Check Krill Oil interactions with other supplements →
BenefitsDosage GuideSide EffectsTypes & FormsResearchFAQ

Related Conditions

Heart HealthInflammationJoint PainHigh CholesterolBrain Fog & FocusPremenstrual Syndrome (PMS)

Commonly Taken Together

+
Fish Oil
Both support heart-health
See top fish oil products →
+
Omega-3
Both support brain-fog
See top omega-3 products →
+
Astaxanthin
Both support general wellness
See top astaxanthin products →
+
Cod Liver Oil
Both support heart-health
See top cod liver oil products →

Form Comparisons

Fish Oil vs Krill Oil
See which form is right for you →

Related Guides

Omega-3 & Healthy Fats Supplements Guide
How to choose among omega-3 and fat supplements — fish oil, krill, cod liver, flax, algae, MCT — by EPA/DHA content, conversion, and quality, with an oxidation caution.

Related Supplements

Fish OilStrong

Distinguish nutritional fish oil from prescription omega-3 treatment. Triglyceride lowering does not guarantee fewer cardiovascular events, and REDUCE-IT’s result cannot be assigned to every EPA/DHA product. [1,2,13]

Top picks →
Omega-3Strong

Bottom line: Omega-3s have strong evidence for heart, brain, and joint health. Take 1,000-2,000mg EPA+DHA daily — choose triglyceride form fish oil or algal oil for vegans.

Top picks →
AstaxanthinModerate

Astaxanthin has limited skin and biomarker evidence. Antioxidant assays do not prove longevity benefits; adult intake assessments and a reported warfarin interaction matter.

Top picks →
Cod Liver OilModerate

Check the exact EPA, DHA, vitamin A and vitamin D amounts. Cod liver oil is not a proven general disease-prevention supplement; avoid it in pregnancy because of preformed vitamin A.

Top picks →
Flaxseed OilModerate

Flaxseed oil supplies ALA; whole-seed cholesterol and lignan findings do not establish oil benefits. It is not interchangeable with EPA/DHA or a proven cholesterol treatment. [1][7]

Top picks →

Looking for the best krill oil supplement?

We analyzed and ranked the top products based on form, dosage, third-party testing, and value.

See Our Top Picks

Frequently Asked Questions

Is krill oil better than fish oil?

Both provide EPA and DHA. The Ulven trial used different omega-3 doses and found no significant difference in plasma changes; it did not establish a 68% matched-dose red-cell advantage. A network meta-analysis found no significant difference in lipid outcomes. Compare actual EPA+DHA, product quality, cost and tolerance.

Evidence:RCT (2011) · n=113 · moderate confidence[#1]. See full reference list below.

Can I take krill oil if I have a shellfish allergy?

No. Krill are crustaceans, and krill oil may contain proteins that trigger allergic reactions in individuals with shellfish or crustacean allergies. This is an absolute contraindication — anaphylaxis is possible. If you have a shellfish allergy and want omega-3 supplementation, consider algal oil (derived from microalgae), which provides DHA and EPA without any crustacean or fish-derived ingredients.

Why does krill oil cause fewer fishy burps than fish oil?

Some people find one product easier to tolerate, but there is no guarantee that krill oil causes fewer burps or cannot oxidize. Astaxanthin content and phospholipid form do not substitute for good manufacturing, storage and independent product testing.

Evidence:RCT (2011) · n=113 · moderate confidence[#1]. See full reference list below.

How much krill oil should I take daily?

A gram of krill oil is not a gram of EPA+DHA, and concentrations vary. Studies use different products and regimens; no universal amount is established for cardiovascular protection, high triglycerides or PMS. Use the actual EPA+DHA label and clinical advice for a treatment goal.

Evidence:RCT (2011) · n=113 · moderate confidence[#1]. See full reference list below.

Is krill oil sustainable and environmentally friendly?

Krill are part of the Antarctic food web. Environmental claims should be checked against the current fishery and the exact product’s independently verified certification. A certification claim alone is not a guarantee of no ecological impact, and a fixed biomass or harvest percentage can become outdated.

Does krill oil help with joint pain and arthritis?

Evidence is mixed. Recent meta-analyses differ on knee pain, stiffness and function, and individual study percentages should not be assumed to predict a personal response. Discuss persistent joint pain with a clinician rather than relying on krill oil as a treatment.

Evidence:Meta-analysis (2025) · 5 RCTs · n=730 · moderate confidence[#8]. See full reference list below.

Can I take krill oil with blood thinners?

Use caution. Omega-3 fatty acids, including those in krill oil, have mild antiplatelet effects that may increase the anticoagulant action of blood thinners like warfarin, heparin, or antiplatelet drugs like aspirin and clopidogrel. While standard krill oil doses (1-2g) are generally tolerable, you should inform your physician, have your INR monitored more frequently if on warfarin, and report any unusual bruising or bleeding.

When should I stop taking krill oil before surgery?

Tell the surgical team the exact product and dose and follow their instructions. The evidence cited here does not establish a universal 14-day stop rule for every krill-oil user or procedure.

Continue Reading

Condition Guide

Heart Health

CoQ10 (100-300mg/day) lowers blood pressure and improves heart failure outcomes. Omega-3 fatty acids (2-4g EPA/DHA) reduce triglycerides by 20-30%. Magnesium (300-400mg/day) supports healthy blood pressure and heart rhythm. All three have strong evidence from randomized controlled trials.

Product Comparison

Best Krill Oil Supplements

See our top ranked products

References

  1. RCTUlven SM, Kirkhus B, Lamglait A, Basu S, Elind E, Haider T, Berge K, Vik H, Pedersen JI (2011). Metabolic effects of krill oil are essentially similar to those of fish oil but at lower dose of EPA and DHA, in healthy volunteers. Lipids. DOI PubMed
  2. RCTBunea R, El Farrah K, Deutsch L (2004). Evaluation of the effects of Neptune Krill Oil on the clinical course of hyperlipidemia. Alternative Medicine Review. PubMed
  3. Sampalis F, Bunea R, Pelland MF, Kowalski O, Duguet N, Dupuis S (2003). Evaluation of the effects of Neptune Krill Oil on the management of premenstrual syndrome and dysmenorrhea. Alternative Therapies in Health and Medicine. PubMed
  4. Deutsch L (2007). Evaluation of the effect of Neptune Krill Oil on chronic inflammation and arthritic symptoms. Journal of the American College of Nutrition. DOI PubMed
  5. Ramprasath VR, Eyal I, Zchut S, Jones PJ (2013). 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 in Health and Disease. DOI PubMed
  6. Cicero AF, Rosticci M, Morbini M, Cagnati M, Grandi E, Parini A, Borghi C (2016). Lipid-lowering and anti-inflammatory effects of omega 3 ethyl esters and krill oil: a randomized, cross-over, clinical trial. Arch Med Sci. DOI PubMed
  7. Konagai C, Yanagimoto K, Hayamizu K, Han L, Tsuji T, Koga Y (2013). Effects of krill oil containing n-3 polyunsaturated fatty acids in phospholipid form on human brain function: a randomized controlled trial in healthy elderly volunteers. Clinical Interventions in Aging. DOI PubMed
Show 5 more references
  1. Meta-analysisMeng J, Wang X, Li Y, Xiang Y, et al. (2025). Krill oil for knee osteoarthritis: A meta-analysis of randomized controlled trials.. Medicine. DOI PubMed
  2. Pimentel T, Queiroz I, Florêncio de Mesquita C, Gallo Ruelas M, et al. (2024). Krill oil supplementation for knee pain: a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials.. Inflammopharmacology. DOI PubMed
  3. Meta-analysisHuang H, Liao D, He B, Zhou G, et al. (2023). Clinical effectiveness of krill oil supplementation on cardiovascular health in humans: An updated systematic review and meta-analysis of randomized controlled trials.. Diabetes & metabolic syndrome. DOI PubMed
  4. Kim MG, Yang I, Lee HS, Lee JY, et al. (2020). Lipid-modifying effects of krill oil vs fish oil: a network meta-analysis.. Nutrition reviews. DOI PubMed
  5. Meta-analysisUrsoniu S, Sahebkar A, Serban MC, Antal D, et al. (2017). Lipid-modifying effects of krill oil in humans: systematic review and meta-analysis of randomized controlled trials.. Nutrition reviews. DOI PubMed