Fish oil vs krill oil

Fish oil's EPA and DHA are typically bound as triglycerides or ethyl esters; krill oil binds its omega-3s to phospholipids instead, and naturally contains the antioxidant astaxanthin. When a trial matched the EPA and DHA dose exactly, it found no statistically significant difference in blood levels between fish oil and krill oil. Krill oil usually costs more per gram of EPA and DHA and is crustacean-derived, which matters if you have a shellfish allergy.

Fish oil vs. krill oil

	Fish oil	Krill oil
Source	Fatty fish (e.g. sardines, anchovies)	Antarctic krill, a small crustacean
Omega-3 form	Triglyceride or ethyl ester	Phospholipid-bound
Other compounds	Depends on the source; ours adds vitamin E as an antioxidant	Naturally contains astaxanthin, a carotenoid pigment
Allergen	Fish	Crustacean/shellfish-related
Matched-dose bioavailability	No significant difference found vs. krill oil in a 4-week trial	No significant difference found vs. fish oil in the same trial
Typical cost per gram of EPA+DHA	Generally lower	Generally higher

What the research found when the dose was matched

A randomized, double-blind, four-week trial gave 66 healthy adults a matched 1.3 g/day dose of combined EPA and DHA as fish oil ethyl ester, fish oil triglyceride, or krill oil. There was no statistically significant difference in total plasma EPA+DHA between the three groups at the end of the trial — bioavailability differed by less than 24%. That trial was funded by a supplement ingredient manufacturer, which is worth knowing when weighing its conclusion, but it's the most direct head-to-head comparison we've found. At a matched dose, absorption doesn't look like the deciding factor between fish oil and krill oil.

Allergy is the practical difference that matters most

Krill are crustaceans, related to shrimp and other shellfish; people with a shellfish allergy are commonly advised to avoid krill oil for that reason. Fish oil made from sardines and anchovies, like ours, carries a fish allergen instead — fish and shellfish allergies are medically distinct, but if you have either, ask an allergist before taking a marine omega-3 supplement rather than assuming one is safer than the other on your own.

Where our product sits

Electric Tiger Omega-3 is a fish oil, not a krill oil — 1,000 mg of fish oil concentrate per softgel, providing 180 mg EPA and 120 mg DHA, listed as "fish oil concentrate" without a stated ester form. We don't carry a krill oil option. If astaxanthin or a phospholipid-bound form specifically matters to you, that's a reason to look at krill oil rather than fish oil, not a gap in ours to apologize for — they're different products aimed at slightly different preferences.

Questions people ask

Which is better, fish oil or krill oil?

At a matched EPA+DHA dose, a controlled trial found no meaningful absorption difference between them. Cost (krill oil is usually pricier per gram of EPA+DHA), allergen source, and whether astaxanthin matters to you are more likely to decide it than bioavailability.

What is the actual difference between krill oil and fish oil?

Source (crustacean vs. fish) and the chemical form the omega-3s are bound to (phospholipid vs. triglyceride/ethyl ester) are the two structural differences. Krill oil also naturally contains astaxanthin; fish oil doesn't unless it's added separately.

Is krill oil more expensive than fish oil?

Generally, yes, per gram of EPA and DHA — krill oil production is more involved than fish oil extraction, and that's typically reflected in shelf price. See how to compare fish oil prices for the price-per-serving math to run on either.

Sources

• Yurko-Mauro K, et al. Similar EPA and DHA plasma levels achieved with fish oil or krill oil in a randomized double-blind four-week bioavailability study. PMID 26328782.
• Electric Tiger Omega-3 Supplement Facts: product page.

Related reading: types of fish oil compared, how to choose a good fish oil, and fish oil without fillers: reading the other ingredients.