Most krill oil is somewhere between 30 and 50 percent phospholipid by weight, and the percentage matters less than the sellers say and more than the skeptics say. It’s the one number on a krill label that tells you whether you’re holding krill oil at all.
We sell Captains Krill Oil™, so we have a horse in this race. Here’s the honest version anyway: what the number means, what the human trials actually show when you raise it, and why the best use of it is as a fraud check rather than a bragging right.
One housekeeping note. This is about the phospholipid number on a krill oil label. If your question is the bigger one — phospholipid omega-3 versus the triglyceride form in fish oil, and whether the form is worth paying for — we’ve answered that separately. This page is for the person holding two bottles and wondering why one says 40% and the other says 56%.
What “phospholipids” means on a krill oil label
Krill oil is a mix of two kinds of fat. Part of it is ordinary triglyceride — the same storage fat that makes up fish oil. The rest is phospholipid: two fatty-acid tails on a glycerol backbone, plus a phosphate head that makes the molecule water-friendly on one end. It’s the architecture of your own cell membranes. In krill, most of that phospholipid is phosphatidylcholine, and a large share of the krill’s EPA and DHA is bound to it rather than to the triglyceride fraction.
So when a label says “phospholipids 400 mg” per 1,000 mg of oil, it is telling you 40% of the oil is the membrane-type fat and 60% is the storage type. That ratio is what the whole “krill versus fish oil” argument rests on. It’s also the ratio that shifts with how the oil was made.
The actual numbers
The reference standard is the krill oil monograph in the Food Chemicals Codex, the US Pharmacopeia’s book of food-ingredient specs. Its range for total phospholipids is 28 to 52 percent by weight, with phosphatidylcholine making up 60 to 90 percent of that phospholipid. ConsumerLab uses the same range when it tests krill products, measured by phosphorus-31 NMR. Anything inside that band is, by the codex’s definition, krill oil.
Where individual products land:
- Aker BioMarine’s Superba 2, the ingredient behind a large share of the brands on the shelf, runs about 40% phospholipids.
- Superba Boost, the same company’s premium grade, is concentrated after extraction to 56% or more. That’s the “56% phospholipids” you see in Amazon titles.
- Captains: a typical two-softgel serving of 1,000 mg of oil carries about 411 mg of phospholipids — roughly 41%. That’s a recent typical figure, not a locked spec. Ours is a pressed, unconcentrated oil, and a natural catch moves around a little lot to lot. We test lots at random and they come back strong; we’d rather tell you that than print a number we’d have to engineer the oil to hit.
The variance isn’t a manufacturing failure — it’s biology. Krill phospholipid content shifts with season, sex, maturity and where the swarm was feeding; published values for the raw animal range from under 40% in gravid females up to 80% in lab-fractionated oils. An oil that reads exactly the same number every time has been standardized in a plant. An oil that reads 39% one lot and 43% the next came out of a krill.
Does a higher percentage put more omega-3 in your blood?
This is the question the 56% products are selling on, so it deserves a straight answer. There are three trials worth knowing, and they don’t all point the same way.
The one that supports it. In 2015, a Canadian group ran a 20-person crossover trial comparing a high-phospholipid krill oil to a low-phospholipid one. Both delivered 600 mg of omega-3 a day. After four weeks, plasma EPA and DHA rose by the same amount on both — no difference. Red-blood-cell EPA+DHA, a slower and arguably better marker, rose more on the high-phospholipid oil. Three things to read alongside that: the high-phospholipid group swallowed twice as much oil (3 g versus 1.5 g) to get its 1,200 mg of phospholipid; the study was funded by Enzymotec, a company that sold krill oil; and twenty people is twenty people.
The one that doesn’t. Also in 2015, DSM — a fish oil company — put 66 adults on 1.3 g a day of EPA+DHA as fish-oil triglyceride, fish-oil ethyl ester, or krill oil, matched to the milligram. After four weeks, plasma EPA+DHA was the same across all three. Matched for omega-3 dose, the phospholipid form bought nothing in that trial.
The newest one. In May 2026, a University of Sherbrooke team funded by the Canadian Institutes of Health Research published a 72-person, 12-week randomized trial in the American Journal of Clinical Nutrition. Both groups got about 1.1 g a day of omega-3; the krill group (on Superba Boost, the 56% grade) showed roughly 1.5 times the rise in plasma EPA and DHA that the fish oil group did. The authors were careful in a way sellers won’t be: they said the difference is “probably not related to higher absorption” and more likely to how the body handles phospholipid-bound fat after absorption, and that higher plasma levels “do not necessarily translate into superior clinical outcomes.”
Put together: over months, the phospholipid form does seem to raise blood omega-3 more than fish oil at the same dose, and that finding got stronger this year. Whether 56% beats 40% within krill oil rests on one small industry-funded trial where the high group also took double the oil. Nobody has shown that either number changes how your knees feel or what your cardiologist sees. Choosing between two krill oils on the percentage alone is choosing on the thinnest evidence in the category.
Why the number matters anyway: it’s the authenticity check
Here’s the use of the phospholipid line that nobody advertises. Krill oil costs several times what fish oil does, and where there’s a price gap there’s dilution. Cut it with cheap fish oil, or with soy lecithin to keep the phospholipid reading up, and most buyers can’t tell.
Chemists can. A 2018 paper from Deakin University worked through the detection methods: in genuine krill oil the EPA and DHA sit mostly on the phospholipids, so a “krill oil” with a lot of omega-3 on its triglycerides has been topped up with fish oil. Carbon-13 NMR caught anchovy oil at 10% or more; thin-layer chromatography caught fish-oil ethyl esters at 1%; and phosphorus-31 NMR — the same method the codex uses for the phospholipid figure — flags cheap phospholipid sources like soy. ConsumerLab’s krill testing over the years has found products that didn’t contain their expected phospholipids or astaxanthin.
So read the label this way. A phospholipid figure inside 28–52% (or above it with an honest “concentrated” explanation) is consistent with krill oil. A krill oil label with no phospholipid line at all is telling you the maker either didn’t measure the one thing that makes krill oil krill oil, or didn’t want you to see it. Either way, ask.
Reading the label without getting played
Divide, don’t admire. “500 mg phospholipids” from a 1,000 mg serving is 50%; from a 1,500 mg serving it’s 33%. The big number on the front is usually the oil mass, and “triple strength” tells you about the capsule, not the omega-3.
Above the mid-50s means a factory step. Krill don’t make a 56% oil; a plant does, by pulling the triglyceride fraction back out after extraction. That isn’t sinister — it’s real processing — but it’s the opposite of “straight from the animal,” and the evidence that it helps you is the 20-person study above.
Watch the astaxanthin line too. The red pigment travels with the phospholipid; a healthy phospholipid number next to almost no astaxanthin means the oil has been through something.
How Captains lands where it lands
Our oil is pressed mechanically on the boat from fresh-caught krill — no solvents at any stage, no concentration step afterward. Around 41% phospholipid is simply where an unconcentrated pressed oil comes out, which is why it sits right in the middle of the codex range rather than above it. We’ve made it the same way for twenty years. You’ll notice it’s not the biggest number on the shelf, and we’re not going to dress it up.
You might not need us
If you eat fatty fish twice a week, skip the capsule and this whole debate. If you want the most EPA and DHA per dollar, a good triglyceride fish oil wins on price and the matched-dose evidence says you’re not losing much. If a high phospholipid number is what you want, buy a Superba Boost–based product — that’s the honest recommendation, and it isn’t us. Captains is for the person who wants a raw, unconcentrated oil from a boat and is willing to accept a number that moves a little because nobody engineered it.
Honest answer, not a pitch. — captainskrilloil.com
Frequently asked questions
What percentage of phospholipids should krill oil have?
The Food Chemicals Codex monograph puts genuine krill oil at 28–52% total phospholipids by weight, with phosphatidylcholine making up 60–90% of that. Standard ingredients like Superba 2 run about 40%; concentrated grades like Superba Boost run 56% or more. Anything in or above that band is consistent with real krill oil.
Is 56% phospholipid krill oil better than 40%?
It contains more phospholipid per capsule, which is what it says. Whether that does more for you rests on one 20-person, industry-funded trial in which the high-phospholipid group also took twice the oil and showed higher red-cell omega-3 but identical plasma levels. No trial has tied the percentage to a health outcome.
How many mg of phospholipids are in Captains Krill Oil?
A typical two-softgel serving of 1,000 mg of oil carries about 411 mg of phospholipids, roughly 41%. That’s a recent typical figure for a pressed, unconcentrated natural oil, not a locked spec — it moves a little lot to lot, and we test lots at random rather than engineering the oil to hit a number.
Can a krill oil be faked or diluted, and how would I know?
Yes. Krill oil can be cut with cheaper fish oil or soy lecithin, and chemists detect it with NMR and chromatography by looking at where the EPA and DHA sit and what kind of phospholipid is present. As a buyer, the practical check is whether the label states a phospholipid figure inside the codex range at all; a krill oil with no phospholipid line is a reason to ask questions.
Why does the phospholipid content of krill oil vary?
Because krill are animals. Their lipid makeup shifts with season, sex, maturity and feeding grounds, so an unconcentrated oil naturally reads a few points differently from one lot to the next. An oil that reads identically every time has been standardized in a plant; that’s a processing choice, not a sign of higher quality.