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Dietary supplement

Krill Oil 500 mg Ingredients & Drug Interactions

by Puritan's Pride

Krill Oil 500 mg label
See full label image
Softgel Capsule Category: Fat/fatty Acid
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Krill Oil 500 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Krill Oil 500 mg is a dietary supplement by Puritan's Pride with 1 active ingredient. Its ingredients are commonly taken for heart and cholesterol support, high triglycerides, joint pain and inflammation.Based on those ingredients, 838 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Ester-Omega Krill Oil. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Krill Oil 500 mg by Puritan's Pride

Ask about any prescription or over-the-counter medication and we check it for interactions with Krill Oil 500 mg by Puritan's Pride — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Krill Oil 500 mg by Puritan's Pride

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Aug 13, 2026

What’s inside

Partial disclosure
Ingredient Transparency · database check
Partial

Most active ingredients list an amount, but at least one is hidden in a blend or missing.

Why this rating?
  • The label discloses an exact amount for 4 of its 5 active ingredients.
  • “Total Omega-3 Fatty Acids” is listed as a grouped ingredient — the label gives one combined amount (86 mg) without saying how much of each component you get.
  • “Ester-Omega Krill Oil” is listed as a grouped ingredient — the label gives one combined amount (500 mg) without saying how much of each component you get.

This formula contains 5 active ingredients centered on krill oil and its components. Eicosapentaenoic acid and docosahexaenoic acid are omega-3 fatty acids derived from krill, along with phospholipids that help your body absorb them.

Astaxanthin is a red pigment from krill with antioxidant properties. The label also groups total omega-3 fatty acids and other fatty acids as active ingredients.

Gelatin, vegetable glycerin, and sorbitol serve as inactive ingredients — the capsule shell and thickening agents.

Does it work?

Insufficient evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Insufficient

There isn't enough reliable clinical evidence to rate this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: May reduce the risk of coronary heart disease.
  • We looked for evidence on: Cardiovascular disease (CVD), Hypertriglyceridemia, Hyperlipidemia, Hypertension, Heart failure, Stroke — and 2 related terms.
  • The closest evidence on file: Astaxanthin is rated "Insufficient Reliable Evidence To Rate" for Heart failure (Natural Medicines).
  • Also on file: Astaxanthin is rated "Insufficient Reliable Evidence To Rate" for Hyperlipidemia, Hypertension, Stroke.

The evidence we hold shows insufficient reliable data to rate astaxanthin for the conditions listed — age-related cognitive decline, macular degeneration, aging skin, Alzheimer disease, athletic performance, and carpal tunnel syndrome. That doesn't mean it doesn't work; it means research so far hasn't established it clearly enough to make a claim.

For the omega-3 components and other ingredients in this krill oil product, we have no effectiveness ratings on file.

The evidence, ingredient by ingredient Krill Oil Astaxanthin

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Astaxanthin is generally well tolerated in studies, though long-term safety data are limited. The most common side effects reported are abdominal pain, diarrhea, and red fecal color — the latter is typically harmless and related to the astaxanthin pigment itself.

At very high doses (40 mg daily), severe stomach pain has been reported in a small number of people. Regarding pregnancy and breastfeeding, the safety data for astaxanthin are not sufficient, so it's best to avoid this product during pregnancy and while breastfeeding.

We have no pregnancy or breastfeeding safety data on file for the other ingredients.

Side effects, ingredient by ingredient Krill Oil Astaxanthin

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Astaxanthin.
  • The most serious interaction on file is rated Moderate.
  • For scale: 672 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check your medications against two enzyme-processing categories: CYP3A4 substrates and CYP2B6 substrates. Both carry a Moderate risk that astaxanthin could lower their levels.

Because the CYP3A4 group is very large, your doctor or pharmacist can quickly tell you if any of your drugs fall into it.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glancePartially disclosed formula with insufficient evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Krill oil can be a source of omega-3 fatty acids and astaxanthin, but the astaxanthin content here interacts with a very large number of medications through liver enzyme pathways. If you take any prescription drugs — especially statins, blood pressure medications, or immunosuppressants — check your exact medications with the tool on this page before starting.

Talk with your doctor or pharmacist about whether this product fits your personal situation.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Nov 21, 2019.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Krill Oil 500 mg, straight from the product label.

Brand Puritan's Pride
Net contents 30 Rapid Release Softgel(s)
Market status On market
Date entered into DSLD Nov 21, 2019
DSLD ID 207676
Product type Fat/fatty Acid
Supplement form Softgel Capsule
Dietary claims / uses Nutrient, All Other, Qualified Health
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Krill Oil 500 mg by Puritan's Pride, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Softgel(s)
Maximum serving Sizes:
1 Softgel(s)
IngredientAmount% DV
Eicosapentaenoic Acid40 mg--
Docosahexaenoic Acid25 mg--
Phospholipids202 mg--
Astaxanthin101 mcg--
Total Omega-3 Fatty Acids86 mg--
Other Fatty Acids0 NP--
Ester-Omega Krill Oil500 mg--

Other ingredients: Gelatin, Vegetable Glycerin, Sorbitol

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formula

86mg active omega-3

Ester-Omega

Contains shellfish (krill) ingredients.

General Statements

May reduce the risk of coronary heart disease (see side panel)

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: For adults, take one (1) softgel daily, preferably with a meal.

Precautions

Contains shellfish (krill) ingredients.

Formulation

No artificial color or flavor, no preservatives, no sugar, no starch, no milk, no lactose, no gluten, no wheat, no yeast. Sodium free.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Krill Oil 500 mg by Puritan's Pride label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Krill Oil 500 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Krill Oil 500 mg by Puritan's Pride

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Softgel(s) Dosage formSoftgel Capsule Amounts shown are per serving.

Ester-Omega Krill Oil

Interacts with
208 drugs
500 mg per serving

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 triglyce...

Ester-Omega Krill Oil monograph & interactions
  • › Phospholipids
  • › Astaxanthin
  • › Total Omega-3 Fatty Acids

Other (inactive) ingredients: Gelatin, Vegetable Glycerin, Sorbitol. These complete the product’s ingredient list but are not active constituents.

Interaction report

Krill Oil 500 mg by Puritan's Pride Drug Interactions

Want to check YOUR meds against Krill Oil 500 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
838Drugs
838 Moderate

Ingredients driving the most interactions

Ester-Omega Krill Oil 208

Individual Drug Interactions

The ingredients in Krill Oil 500 mg interact with 838 drugs. Click any drug to see the details.

1 of the 1 ingredient in Krill Oil 500 mg interact with drugs. Each result below shows which ingredient is responsible. Ester-Omega Krill Oil

Each ingredient & the kinds of drugs it affects

For each ingredient in Krill Oil 500 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Ester-Omega Krill Oil2 drug types · 208 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
Ester-Omega Krill Oil full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Krill Oil 500 mg, from the product label.

Puritan's Pride

See all Puritan's Pride products
Name
Puritan's Pride
Pharmacist Counseling Corner

Krill Oil 500 mg by Puritan's Pride: Common Questions

Does Krill Oil 500 mg by Puritan's Pride interact with any medications?
Yes. Based on its ingredients, Krill Oil 500 mg has a known interaction with 838 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Krill Oil 500 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take Krill Oil while I'm pregnant or breastfeeding?
The safety data for astaxanthin, the main active ingredient we can assess, are not sufficient to say it's safe during pregnancy or breastfeeding. It's best to avoid it in both situations. Talk with your doctor or pharmacist about your individual circumstances.
What does astaxanthin do in this formula?
Astaxanthin is a red pigment from krill with antioxidant properties. We have no reliable evidence yet to rate it for specific health conditions — age-related cognitive decline, macular degeneration, and other uses listed on supplements lack established proof in our data.
Will this supplement cause side effects?
Astaxanthin is generally well tolerated. The most common side effects are abdominal pain, diarrhea, and red-colored stools — the last one is harmless and just the pigment coming through. A small number of people at high doses have reported severe stomach pain.
What are the omega-3 ingredients in krill oil?
This product contains eicosapentaenoic acid and docosahexaenoic acid, two omega-3 fatty acids found in krill, along with phospholipids that help your body absorb them. We couldn't check these three for drug interactions because we hold no data for them.
Is there anything else in this softgel besides the active ingredients?
Yes — the inactive ingredients are gelatin (the capsule), vegetable glycerin, and sorbitol. These are fillers and binders that help deliver the active ingredients.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Krill Oil 500 mg label
Go deeper

The Full Monographs Behind Krill Oil 500 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Krill Oil

Interacts with 208 drugs

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 t...

Read the full Krill Oil monograph → Herb & supplement monograph

Astaxanthin

Interacts with 671 drugs

Astaxanthin is a reddish carotenoid pigment with strong antioxidant activity in the lab, and it is widely promoted for skin, eye, heart, and exercise benefits. Early human studies are promis...

Read the full Astaxanthin monograph →
Sources

Sources & How We Checked

Krill Oil 500 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 16 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Astaxanthin 3 references
  1. Kupcinskas L, Lafolie P, Lignell A, et al. Efficacy of the natural antioxidant astaxanthin in the treatment of functional dyspepsia in patients with or without Helicobacter pylori infection: A prospective, randomized, double blind, and placebo-controlled
  2. Kistler, A., Liechti, H., Pichard, L., Wolz, E., Oesterhelt, G., Hayes, A., and Maurel, P. Metabolism and CYP-inducer properties of astaxanthin in man and primary human hepatocytes. Arch.Toxicol. 2002;75(11-12):665-675. PubMed
  3. Choi HD, Youn YK, Shin WG. Positive effects of astaxanthin on lipid profiles and oxidative stress in overweight subjects. Plant Foods Hum Nutr. 2011;66:363-369. PubMed

See these in context on the Astaxanthin monograph →

Krill Oil 13 references
  1. Leaf A. On the reanalysis of the GISSI-Prevenzione. Circulation 2002;105:1874-5. PubMed
  2. Connor WE. n-3 Fatty acids from fish and fish oil: panacea or nostrum? Am J Clin Nutr 2001;74;415-6. PubMed
  3. Calder PC. N-3 polyunsaturated fatty acids, inflammation and immunity: pouring oil on troubled waters or another fishy tale? Nutr Res 2001;21:309-41. DOI
  4. Bunea R, El Farrah K, Deutsch L. Evaluation of the effects of Neptune Krill Oil on the clinical course of hyperlipidemia. Altern Med Rev 2004;9:420-8.
  5. Sampalis F, Bunea R, Pelland MF, et al. Evaluation of the effects of Neptune Krill Oil on the management of premenstrual syndrome and dysmenorrhea. Altern Med Rev 2003;8:171-9.
  6. Harris WS, Miller M, Tighe AP, et al. Omega-3 fatty acids and coronary heart disease risk: clinical and mechanistic perspectives. Atherosclerosis 2008;197:12-24. PubMed
  7. Tandy S, Chung RW, Wat E, et al. Dietary krill oil supplementation reduces hepatic steatosis, glycemia, and hypercholesterolemia in high-fat-fed mice. J Agric Food Chem 10-14-2009;57:9339-45. PubMed
  8. Maki, K. C., Reeves, M. S., Farmer, M., Griinari, M., Berge, K., Vik, H., Hubacher, R., and Rains, T. M. Krill oil supplementation increases plasma concentrations of eicosapentaenoic and docosahexaenoic acids in overweight and obese men and women. Nutr.R PubMed
  9. Albert BB, Derraik JG, Brennan CM, et al. Supplementation with a blend of krill and salmon oil is associated with increased metabolic risk in overweight men. Am J Clin Nutr 2015;102(1):49-57.
  10. Berge K, Musa-Veloso K, Harwood M, Hoem N, Burri L. Krill oil supplementation lowers serum triglycerides without increasing low-density lipoprotein cholesterol in adults with borderline high or high triglyceride levels. Nutr Res 2014;34(2):126-33. PubMed
  11. Lobraico JM, DiLello LC, Butler AD, Cordisco ME, Petrini JR, Ahmadi R. Effects of krill oil on endothelial function and other cardiovascular risk factors in participants with type 2 diabetes, a randomized controlled trial. BMJ Open Diabetes Res Care. 2015 PubMed
  12. van der Wurff ISM, von Schacky C, Bergeland T, Zeegers MP, Kirschner PA, de Groot RHM. Krill oil supplementation's effect on school grades in typically developing adolescents. Prostaglandins Leukot Essent Fatty Acids 2023;191:102553. PubMed
  13. van der Wurff ISM, von Schacky C, Bergeland T, et al. Effect of 1 year krill oil supplementation on cognitive achievement of Dutch adolescents: A double-blind randomized controlled trial. Nutrients. 2019;11(6):1230. PubMed

See these in context on the Krill Oil monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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