Herb & supplement monograph

Krill Oil Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Krill Oil interacts with medications. The heart of this page is the interaction list — every drug Krill Oil is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Krill Oil is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Krill Oil Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Krill Oil drug interaction appears low for most people. None of the listed interactions are rated major, and all of them rest on theoretical or limited evidence rather than proven effects in people.

Interactions deserving the most attention

The combination that deserves the most attention is krill oil with anticoagulant or antiplatelet drugs, often called blood thinners. Because krill oil contains omega-3 fatty acids, high doses could in theory make platelets less sticky and add to bleeding risk, though this has not been confirmed in people. There is also a theoretical concern that krill oil could lower blood sugar in people taking diabetes medications, but a small human study found no meaningful drop in blood glucose in patients with type 2 diabetes, which is reassuring.

What the rest of the list means

Although krill oil is linked to a long list of medications, that number mostly reflects two broad drug categories rather than many separate proven problems. The concerns are largely theoretical, and where the idea has been tested in people, such as with diabetes medications, the predicted effect did not clearly appear.

Check your medications against Krill Oil

Based on HelloPharmacist’s Krill Oil interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Krill Oil

208 medications have a known interaction with Krill Oil, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Krill Oil using our pharmacist-reviewed interaction data.

AI summaries are generated from our Krill Oil interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Krill Oil combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Krill Oil affects

Every type of medication (drug category) Krill Oil is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 2 drug categories Krill Oil interacts with

Anticoagulant/antiplatelet DrugsAntidiabetes Drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, krill oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Taking high doses of omega-3 fatty acids from fish oil can modestly decrease platelet aggregation. Since krill oil also contains these fatty acids, taking high doses of krill oil might also inhibit platelet aggregation. Theoretically, taking high doses of krill oil with antiplatelet or anticoagulant drugs might increase the risk of bleeding. However, the omega-3 content of krill oil is much lower than that of fish oil.

Likelihood Possible Evidence D

Antidiabetes Drugs

Theoretically, taking krill oil with antidiabetes drugs might increase the risk of hypoglycemia.
Some research in animals and humans shows that krill oil might lower blood glucose levels. However, a small study shows that taking krill oil does not reduce blood glucose levels in patients with type 2 diabetes, most of whom were taking antidiabetes drugs.

Likelihood Possible Evidence B

Monograph

Krill Oil: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Krill oil is a source of omega-3 fatty acids (EPA and DHA) bound to phospholipids, which may help absorption. It is most studied for lowering triglycerides and supporting heart health, but the evidence for many other uses is limited. It is generally well tolerated, but people with shellfish allergy should avoid it, and anyone pregnant, breastfeeding, or on blood thinners should check with a pharmacist or doctor first.

Scientific name: Euphausia superba
Family: Euphausiidae
Part used: Oil extracted from the whole krill
Common forms: Softgel capsules, liquid

People commonly use it for

Heart and cholesterol support
High triglycerides
Joint pain and inflammation
Brain and eye health
PMS symptoms
General omega-3 supplementation

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally well tolerated, but avoid if you have a shellfish allergy and use caution if you have a bleeding disorder.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Krill oil is a dietary supplement made from krill, which are tiny shrimp-like crustaceans found in the ocean. Most krill oil comes from Antarctic krill (Euphausia superba) harvested from the cold waters of the Southern Ocean.

Like fish oil, krill oil is rich in omega-3 fatty acids, mainly EPA and DHA. A key difference is that in krill oil a large share of these omega-3s are attached to phospholipids rather than triglycerides. Some makers say this form is absorbed more easily, though the practical importance of this is still debated. Krill oil also naturally contains a reddish antioxidant called astaxanthin, which gives it its color.

People take krill oil for many of the same reasons they take fish oil, including heart health, healthy cholesterol and triglyceride levels, and joint comfort.

How it works

The main active ingredients in krill oil are the omega-3 fatty acids EPA and DHA. These fats are building blocks the body uses to make signaling molecules that help control inflammation, and they are important parts of cell membranes, including in the brain and eyes.

In krill oil, much of the EPA and DHA is carried on phospholipids. Laboratory work suggests this form may mix more easily with the body's own fats, which is the basis for claims about better absorption. Krill oil also contains astaxanthin, an antioxidant that may help protect the oil from spoiling and that has been studied for its own antioxidant effects.

Many of the proposed benefits come from lab and animal studies, so the way these effects translate to real health outcomes in people is still being worked out.

Effectiveness

Does Krill Oil work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 22 uses evaluated

1 Possibly effective 21 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Effective Dry eye