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Krill Oil: Uses, Dosage, and Safety Information

Last reviewed: December 2025

Overview

Krill oil is a dietary supplement derived from Antarctic krill, small crustaceans that resemble shrimp. Like fish oil, krill oil provides omega-3 fatty acids (EPA and DHA), but with key structural differences that may offer absorption and tolerability advantages.

The omega-3s in krill oil are bound to phospholipids rather than triglycerides, which may improve how the body absorbs and utilizes them. Krill oil also naturally contains astaxanthin, a powerful antioxidant that gives it its distinctive red color.

Common Brand Names

  • MegaRed
  • Viva Naturals Krill Oil
  • Sports Research Antarctic Krill Oil
  • NOW Foods Neptune Krill Oil
  • Dr. Mercola Krill Oil

Primary Uses

Krill oil is commonly used for:

  • Heart health support — similar omega-3 benefits as fish oil
  • Joint comfort — anti-inflammatory properties
  • Brain health — DHA supports cognitive function
  • Cholesterol support — may help maintain healthy lipid levels
  • PMS symptom relief — some evidence for menstrual comfort
  • Skin health — astaxanthin provides antioxidant support

How It Works

Krill oil provides benefits through several mechanisms:

  • Phospholipid-bound omega-3s: This form may be more readily incorporated into cell membranes
  • EPA and DHA: Same active omega-3s as fish oil, supporting cardiovascular and brain health
  • Astaxanthin: Potent antioxidant that protects the oil from oxidation and provides additional health benefits
  • Anti-inflammatory effects: Omega-3s produce specialized pro-resolving mediators

Key Differences from Fish Oil

  • Form of omega-3s: Phospholipid-bound (krill) vs. triglyceride-bound (fish oil)
  • Absorption: Some studies suggest better absorption with krill oil
  • Antioxidant content: Krill oil contains astaxanthin; fish oil does not
  • Dose needed: May require smaller doses for similar effects
  • Sustainability: Krill fisheries are carefully managed but remain a consideration

Safety Considerations

Krill oil is generally safe but has specific considerations:

  • Shellfish allergy: Avoid if allergic to shellfish (krill are crustaceans)
  • Blood thinning: Similar anticoagulant effects as fish oil
  • Cost: Typically more expensive than fish oil
  • Surgery: May need to stop before surgical procedures

Sources

  • National Institutes of Health Office of Dietary Supplements — Omega-3 Fatty Acids
  • Ulven SM, et al. Metabolic effects of krill oil. Lipids Health Dis. 2011
  • Ramprasath VR, et al. Supplementation of krill oil vs fish oil. Lipids Health Dis. 2015
Last reviewed: December 2025