Is Krill Oil Worth It? What the Absorption Trials Show

Krill oil is a different package for the same omega-3 fats, and the question is whether the package matters. Here is what three human trials measured, including where they disagree.

Krill are tiny marine crustaceans. In krill oil, the omega-3 fats EPA and DHA are bound mostly to phospholipids, the same type of fat that cell membranes are made from. NIH's NCCIH^[4] describes krill oil as containing omega-3s in the form of phospholipids.

Most fish oil carries omega-3 as triglycerides or ethyl esters, which are two other chemical forms. Whether the form changes how much reaches the blood is the question the trials below try to answer.*

Krill oil also contains astaxanthin, a red pigment with antioxidant activity. That is where the deep red color comes from.

For more background on the form difference, see our article Krill Oil vs Fish Oil: What Three Small Trials Found.

The longest and most recent trial ran 12 weeks and compared krill oil with fish oil at similar omega-3 amounts.

Who took part: 72 healthy adults aged 30 to 65, 53 of them women, 36 per group (American Journal of Clinical Nutrition, 2026^[1]).

Daily dose: Four 1,000 mg capsules, about 1.1 g of omega-3. The krill group got 706 mg EPA and 393 mg DHA a day. The fish oil group got 738 mg EPA and 462 mg DHA.

What changed: Blood EPA rose about 1.4 times more with krill oil, and DHA about 1.5 times more. The EPA gain was about 1.5 times larger in women than in men.

The catch: The study aimed for 160 people and finished with 72, so it had limited power for smaller effects. It measured plasma only and covered healthy middle-aged adults. The krill capsules also contained choline, which the authors note could be a confounder.

The Canadian Institutes of Health Research funded the trial, and the authors reported no conflicts of interest.

The 4-week trial

Who took part: 66 healthy adults in three groups of 22 (Lipids in Health and Disease, 2015^[2]).

Daily dose: 1.3 g of EPA plus DHA from fish oil ethyl ester, fish oil triglyceride, or krill oil.

What changed: Average plasma EPA plus DHA was about 119 µg/mL with krill oil, 108 with triglyceride fish oil and 91 with ethyl ester fish oil. The authors concluded that plasma levels were similar across the three forms.

The catch: Krill oil had the highest average, but the difference did not reach statistical significance (p = 0.052). An omega-3 ingredient maker funded the study.

The single-dose crossover

Who took part: 15 adults who finished all three test periods, each lasting 72 hours (Lipids in Health and Disease, 2015^[3]).

What changed: Krill oil produced a larger rise in EPA plus DHA in plasma phospholipids than fish oil (p = 0.003). Krill meal, which carries the same kind of phospholipids, did not differ from fish oil.

The catch: Because of the krill meal result, the authors said the data argue against phospholipids being the reason for the difference. It was a single dose in a small group, funded by a krill company.

So the evidence is strongest in the 12-week trial. The shorter trials did not show a clear gap, and they do not settle why krill oil may raise levels more.

The number on a front label is often the weight of the oil, not the omega-3 in it. A 1,000 mg softgel is 1,000 mg of oil. Only part of that is EPA and DHA.

To compare cost fairly, use this method:

• Find EPA plus DHA per serving on the Supplement Facts panel.
• Divide the price of the bottle by the total EPA plus DHA in it.
• Then consider form, since the 12-week trial found krill oil raised blood levels more at similar omega-3 amounts.*

The 2026 trial used four capsules a day to reach about 1.1 g of omega-3, so servings differ by product.

The product below is a krill oil softgel. The label lists 1000 mg of krill oil per softgel with 300 mcg of astaxanthin, and it does not list EPA or DHA amounts here.

Takeaway: The best-designed trial of the three found a larger rise in blood EPA and DHA with krill oil. For adults without a shellfish allergy, that makes the phospholipid form a reasonable one to choose.*

For reference, our omega-3 has 1000 mg of krill oil per softgel, with astaxanthin.

Krill are crustaceans, like shrimp and crab. People with a shellfish or seafood allergy should avoid krill oil.

Krill oil softgels can use a gelatin shell, so they are not suitable for strict vegetarians. Check the label.

Side effects of omega-3 supplements are usually mild, according to NIH's NCCIH^[4]. They can include an unpleasant taste, bad breath, headache, heartburn, nausea and diarrhea.

Check with your doctor first if you:

• have a shellfish or seafood allergy
• take warfarin, aspirin or other blood thinners
• are pregnant or breastfeeding
• are giving it to a child
• have a health condition or take other medication

The European Food Safety Authority (EFSA, 2012^[5]) concluded that supplemental EPA and DHA combined, up to 5 g a day, did not raise safety concerns for adults.