Even if you’ve only dabbled in the world of supplements, you’ve probably heard a lot about fish oil. Many people consider their daily fish oil supplement as essential to their health routine as a multivitamin—and for good reason, considering the slew of benefits it’s been linked to.
That said, there’s another fish-sourced supplement that should be on your radar: krill oil.
Here, we dive into the difference between fish oil and krill oil so you can figure out which best suits your needs.
Fish Oil Basics
Your standard fish oil supplement is made by extracting the oil from fatty fish like salmon, mackerel, herring, and/or sardines.
Fish oil contains high levels of omega-3s (particularly DHA and EPA), a type of fat that’s been linked to all sorts of health benefits. According to The Vitamin Shoppe nutritionist Brittany Michels, R.D.N., omega-3s support brain, heart, and eye health, along with your immune system.
Michels, who has a family history of health challenges, takes fish oil daily. She even chooses to increase her dose during ultramarathon training season to support her immune system.
What’s The Deal With Krill Oil?
Krill oil, on the other hand, is extracted from tiny crustaceans called Antarctic krill, a dietary staple of marine animals like whales and penguins.
Like fish oil, krill oil contains the omega-3 fatty acids DHA and EPA. The difference, though, is that krill oil has a different molecular structure than your standard fish oil. Instead of being an ethyl ester or triglyceride form, krill oil is a phospholipid.
What does this mean—and why does it matter? Some studies have found that krill oil’s unique structure and form make it easier for the body to absorb and use, Michels says.
Plus, on top of the omega-3s, krill oil also contains an antioxidant called astaxanthin, which research suggests offers additional heart health benefits—and may keep krill oil from going rancid as quickly as fish oil. (FYI: It also gives krill oil a distinct reddish hue.)
The Science On Krill Oil vs. Fish Oil
As research comparing fish oil and krill oil develops, keep the following highlights in mind:
First and foremost, both fish oil and krill oil can effectively help you up your omega-3 levels. One study published in Lipids in Health and Disease, for example, identified no significant difference between the DHA and EPA levels of people who took either krill or fish oil for four weeks.
Krill oil contains DHA and EPA in a lower amount than fish oil, but the same omega-3 benefits apply, Michels explains.
Since we store fish oil as triglycerides in our blood, it more effectively increases blood levels of EPA and DHA. Meanwhile, we store up to 65 percent of krill oil’s omega-3s as phospholipids in our cells instead.
The takeaway: Even though we don’t store as much of krill oil’s omegas in our blood, we still reap their benefits.
Research suggests krill oil may have another unique advantage: One Alternative Medicine Review study comparing placebo, fish oil, and krill oil supplements over a three-month period linked krill oil with the greatest blood sugar, triglyceride, and cholesterol benefits.
So, Should You Take Krill Oil Or Fish Oil?
According to Michels, most of us can benefit from supplementing with either fish or krill oil. After all, the standard American diet generally lacks omega-3s. (Upping omega-3s is especially important, though, for those with family or personal health concerns, such as heart disease, she says.)
Generally, if price is a concern, traditional fish oil is a more budget-friendly option. Krill oil supplements tend to be more expensive, perhaps because of the quantity of krill needed to produce them, Michels says.
Since fish oil and krill oil may have a blood-thinning effect, talk to your doctor before supplementing with them—especially if you have any health conditions or take medication.
If you have a fish or shellfish allergy—or dietary restrictions—consider an algae-based omega-3 supplement instead.
Shopping For Fish And Krill Oil
When looking for a fish or krill oil supplement, “choose brands with high purity standards to ensure low environmental contaminants,” says Michels. “Harmful chemicals and toxins [like mercury] are stored in fish’s fat cells, so finding trustworthy sources is crucial.”
You’ll also want to take a look at your supplement’s ingredients. Michels recommends avoiding products with added sugars, corn syrup, colors, or artificial preservatives.
Plus, if you’re purchasing krill oil, check that the supplement doesn’t also contain a mix of other fish oils. You’re paying for krill—so that’s what you should get!
Not sure where to start? Michels recommends The Vitamin Shoppe brand as a high-quality, third-party tested option. Check out The Vitamin Shoppe brand‘s Premium Omega-3 Fish Oil with Vitamin D and Krill Oil.