Krill Oil vs. Fish Oil: 6 Reasons Why Krill Is the Better Choice

Krill oil is a type of omega-3 fatty acid that comes from small shrimp-like crustaceans called krill. These creatures move in swarms (more than 10,000 krill per cubic meter of water, in fact) throughout the Antarctic Ocean feeding on microscopic algae, while also serving as a food source for various ocean dwellers including whales, penguins, and seals.

While they may be quite small (about 2 inches in length), krill make up a crucial component of the ocean's ecosystem. Krill literally means “whale food” in Norwegian, and therefore, is the main diet for most marine predators. So much so that it’s referred to as the “keystone species” of the Southern Ocean.

Fun Fact: Blue whales consume nearly 4 tons (that’s 8,000 pounds!) of krill every day.

One of krill’s underrated superpowers is its extremely high levels of omega-3 fatty acids—particularly DHA and EPA—two long-chain fatty acids that are essential for basic brain functions (1).

In addition to this, research supports krill oil supplementation and its potential to improve the following (1, 2, 3, 4):

• Spacial memory and learning
• Memory loss
• Systemic and central inflammation
• Depression symptoms
• Post-exercise immune function
• Hyperlipidemia
• Rheumatoid arthritis

Krill oil and fish oil are vastly different. Some of their main differences include:

1. What They’re Sourced From

Krill oil is derived from krill while fish oil is derived from a variety of fatty fish like anchovies, mackerel, and salmon.

2. Antioxidant Profile

Krill contains the essential antioxidant, astaxanthin, whereas fish oil does not.

Astaxanthin is what gives krill their reddish color, and may provide heart health benefits due to its anti-inflammatory and antioxidant properties (5).

3. Effectiveness Per Dose

When it comes to effectiveness per dose, krill oil takes the lead.

One 2004 study found that at equal and lower doses, krill oil was significantly more effective than fish oil in the reduction of glucose, triglycerides, and LDL levels (6).

Yes, krill oil is superior to fish oil when it comes to omega-3 supplementation. But, what makes it a better option?

Here are the top 6 reasons...

1. Krill Oil Has Better Absorption

Bioavailability is a term used to describe how much of a substance (EPA and DHA in this case) enters the circulatory system and is used by the body.

With every supplement or medication, some of what you consume is simply excreted and not used by your body. Therefore, bioavailability is an important consideration for nutritional supplements since it indicates how much of an actual effect a substance will have on the body.

Studies have found krill oil has a much higher bioavailability than fish oil, meaning that your body readily absorbs krill oil more effectively than it absorbs fish oil (7).

2. Krill Oil Is More Potent

Potency refers to how much of a substance is needed to produce the desired effect. In the case of omega-3s, the desired effect is the health benefits they may offer: A reduced risk of cardiovascular disease, a significant reduction in inflammation, an improvement in depressive symptoms, and more (8, 9, 10, 11).

A 2011 study, found that krill oil is much more potent than fish oil. So much so that some participants received 63% less krill oil than fish oil. And those that took krill oil still had higher levels of EPA and DHA.

While krill oil and fish oil share similar fatty acid profiles, the EPA content in krill is double that of fish oil (7). This proves that you need far less krill oil than fish oil to get the same results (12).

3. Krill Oil Resists Oxidation

Even though polyunsaturated fatty acids (PUFAs) are great for you, the very fact that they are unsaturated also makes them unstable.

There are many techniques that can prevent omega-3s from oxidizing, so it’s crucial that any omega-3 supplement you take comes from a reputable supplier.

Oxidation is not ideal, namely for the following two reasons:

1. Oxidation makes your supplement go rancid.
2. Oxidation creates free radicals (unless there are antioxidants present).

Free radicals are little groups of unpaired atoms that float around your body, pulling electrons off of stable molecules, causing illnesses like atherosclerosis, inflammatory joint disease, diabetes, and more (13).

Research has found krill oil to be significantly more stable than fish oil for two reasons (14):

1. Krill oil naturally contains the antioxidant, astaxanthin.
2. Krill oil’s EPA and DHA are bound to phospholipids (which are readily absorbed by your body), whereas fish oil requires more processing and promotes oxidation.

4. Krill Oil Contains Phospholipids

The EPA and DHA in fish oil is bound to triglycerides, while the EPA and DHA in krill oil is bound to phospholipids (7). This difference plays a significant role in how much your body absorbs.

You know how oil separates from water or vinegar?

That’s how omega-3s are in your body without the support of another substance to help bind them together. For krill oil, those substances are phospholipids. Unfortunately, fish oil doesn’t have this added benefit, making it less absorbable and therefore less effective.

5. Krill Oil Is Free of Contaminants

You’ve probably heard that it’s not the healthiest choice to eat a lot of sushi…

This is due to the high levels of mercury. Because the fish in sushi is high on the food chain (meaning they eat a lot of little fish), they accumulate toxins and heavy metals. For this reason, it’s recommended to not consume certain fish more than a couple of times a month. It’s also why krill oil is a better source for omega-3s (15).

Krill oil doesn’t have the issue of bioaccumulation of toxins and metals because krill is at the bottom of the food chain. Krill feed on phytoplankton instead of other contaminated fish—making them a much safer source of omega-3s.

6. No Fishy Aftertaste

You know how when you take a fish oil capsule, you always get those fishy burps?

You’d think you’d get those same distasteful burps with krill oil capsules, but you don’t!

This is because they don’t dissolve in your stomach. Rather, they stay intact well into your intestines. Which means: No fishy burps or aftertaste!

When it comes to supplementing with krill oil, the recommended dosage is based on the amount of DHA and EPA found in the supplement.

Krill is a natural blood thinner. So, if you’re currently taking blood thinners, it’s important to be extra mindful of how much krill oil you’re consuming, as it may be a contra-indication. To to be safe, start with a lower dose of krill oil, like 500 milligrams (mg) (16).

This is a “maintenance dose” rather than what you might get prescribed in a clinically setting. For those without cardiovascular risk, it’s safe (and perfectly healthy) to consume a combined EPA and DHA dosage between 250 and 500 mg, which may, depending on the krill oil product, equate to 1,200 to 5,000 mg of krill oil.

Serving sizes among krill supplements varies greatly. So it’s important to talk to a healthcare professional before adding any new supplements to your wellness regimen.

Yes, you can take krill oil and fish oil together. However, if you were going to choose one supplement, krill oil may be the optimal choice due to its higher concentration of EPA (the omega 3 that gives krill its bright red pigment) and astaxanthin (a powerful antioxidant that reduces inflammation).

If you are going to take both of them together, be sure to only take the minimum recommended serving size so that you aren’t overloading on omega 3s.

Because omega-3s have anti-clotting effects at high doses, talk to your doctor if you are:

• Taking blood thinners
• Preparing for surgery
• Pregnant or breastfeeding

Native Note: In addition, if you have any allergies to fish or shellfish, err on the side of caution and get your omega-3s from foods like walnuts, MCT oil, and pasture-raised eggs.