Krill oil is the oil derived from a shrimp-like creature called krill. The oil is rich in fatty acids, similar to fish and cod liver oil. The oil is used for aquaculture farming, krill oil supplements, food for home-based aquariums, and human consumption. Krill is typically located in the colder ocean waters, such as the oceans of Antarctica, Japan and Canada.

Krill. Image credit: Flickr
Krill. Image credit: Flickr

The tiny animal is basically food for several ocean-based animals such as whales, penguins, fish, squid, and seals. This is probably why “krill” is also considered “whale food” in Norway. There are varied krill species and different krill oil supplement brands could use any of these species to make the oil.


Krill oil supplements. Image credit: Flickr
Krill oil supplements. Image credit: Flickr

As aforementioned, krill oil is enriched with fatty acids (omega-3 fatty acids), which are essentially beneficial fats that help reduce swelling and cholesterol. Unlike the omega-3 fatty acids found in fish oil, krill oil fatty acids are assimilated and transported to the cells as phospholipids. Phospholipids are basically types of lipids that help protect cells and provide them their structure.

These lipids are naturally water-soluble, which means it’s easier for the body to absorb phospholipids. Fish oil omega-3s, on the other hand, are appended to triglycerides that do not readily get assimilated by the body. This indicates the omega-3s from the krill oil get absorbed better by the human body, making smaller quantities of krill oil omega-3s as effective as larger dosages of fish oil omega-3s.

The oil also comprises phospholipid-derived fatty acids (PLFA) that help compose cellular membrane; and astaxanthin, a naturally occurring powerful carotenoid pigment or an antioxidant that decreases the body’s free radicals. Astaxanthin is derived from algae that krill feeds on, and is the reason why crustaceans such as krill and lobster have a reddish-pink hue.

The antioxidant helps protect krill oil supplements or their good fat content from turning rancid. In other words, krill oil can stay good even post several hours of exposure to oxygen. Fish oil usually does not have such level of resistance, thanks to its lack of astaxanthin.

Health Benefits

Krill oil, similar to fish oil, may help with multiple health issues such as heart disease, high blood pressure, high cholesterol, cancer, stroke, depression, osteoarthritis, painful menstrual periods, premenstrual syndrome, etc. The oil has anti-inflammatory properties, improves brain health, helps with maintaining healthy blood sugar and cholesterol levels, boosts immunity, promotes healthy liver function, helps ease premenstrual syndrome anguish, etc.

Side Effects

There is not much research done to learn the likely side effects of krill oil supplements. However, effects such as heartburn, bad breath, fishy taste, nausea, loose stools, and upset stomach are possible. Though the fishy aftertaste is present with krill oil, it’s not as bad as fish oil. In fact, some people may not experience any aftertaste at all with krill oil. Breathing difficulties, swelling of the lips, face, throat, or tongue could be issues too with krill oil but the effect would vary greatly across individuals.

People who suffer from seafood allergy may find krill oil supplements allergy-causing too. The oil could slow down blood clotting, which increases bleeding risks during and post-surgery. It’s therefore recommended to not administer krill oil a few weeks before surgery.


There’s no right or standard krill oil dosage. The dosage recommendations would invariably be mentioned on the product packaging. It’s advised to confirm a dosage pattern with a physician on-board as the actual dosage could depend on multiple attributes such as the user’s health, age, and medical conditions (if any). The physician would also advise whether krill oil would hamper or interfere with certain other medications.

Generally, hormone replacement or birth control pills, blood thinners, aspirin, beta-blockers (drugs for improved cardiac action), diuretics, etc. don’t go well with krill oil. Like most supplements and medications, krill oil supplements work best when taken with food.

Krill Oil Harvesting Controversy

Illustrative image of krill. Image credit: Flickr
Illustrative image of krill. Image credit: Flickr

As mentioned before, krill is a major food source for different ocean-based creatures. Therefore, killing krill for commercial reasons or to make krill oil supplements would mean snatching away the food of those particular animals. But is that really the case? Supporters of krill oil products claim krill is abundantly available and the possibilities of over-harvesting are none to slim.

According to Dr. Mercola, krill is the world’s largest biomass and if all the krill on the planet had to be weighed, the species would outweigh almost all other creatures on the planet – such as fish, insect, rat, bird, whale, and even humans. According to some, this claim is hilariously inaccurate. They say bacteria are the planet’s largest biomass, followed by fungi.

Those who oppose krill oil harvesting have a different story to unfold. Unlike proponents of krill oil who only talk about the global krill population, these critics believe krill oil harvesters are ignoring the fact that localized krill over-harvesting has no connection to krill numbers across the globe.

Some commercial fisheries in places where krill is available in abundance are harvesting krill to feed their fish farms. The majority of the harvesting is carried out for aquaculture feed and sport fishing bait. Minimum levels of the harvested krill oil are consumed by humans, and less than 10 percent of that oil is used to make supplements.

Long story short, though krill harvesting doesn’t seem to be endangering the creature on a global level, krill harvesting in certain places may hurt the biodiversity of those regions.

Advice to Buyers

Krill oil is a fairly recent entrant to the world of “good fatty acids”, “EPAs” and “DHAs”. This is why there’s not much research endorsing or banishing krill oil. For those who’d like to be extremely certain about the EPAs and DHAs they ingest, administering the tried-and-tested fish oil is recommended till a lot more studies are carried out to understand krill oil’s qualities and benefits.