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Dietary supplement

NKO Neptune Krill Oil 500 mg Ingredients & Drug Interactions

by Source Naturals

NKO Neptune Krill Oil 500 mg label
See full label image
Softgel Capsule Category: Other Combinations
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 NKO Neptune 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

NKO Neptune Krill Oil 500 mg is a dietary supplement by Source Naturals with 2 active ingredients. Its ingredients are commonly taken for antioxidant support, skin health and aging, eye health.Based on those ingredients, 838 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Astaxanthin, Neptune Krill Oil. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against NKO Neptune Krill Oil 500 mg by Source Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with NKO Neptune Krill Oil 500 mg by Source Naturals — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of NKO Neptune Krill Oil 500 mg by Source Naturals

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 27, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 4 of its 4 active ingredients.
  • “Total Omega-3 Fatty Acids” is listed as a grouped ingredient — the label gives one combined amount (250 mg) without saying how much of each component you get.
  • “Neptune Krill Oil” is listed as a grouped ingredient — the label gives one combined amount (1 Gram(s)) without saying how much of each component you get.

This product contains 4 active ingredients: eicosapentaenoic acid and docosahexaenoic acid (two omega-3 fatty acids from krill), total omega-3 fatty acids, and astaxanthin, a natural pigment. The inactive ingredients are gelatin, glycerin, and purified water that make up the softgel capsule.

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: Heart health and cell membrane integrity.
  • We looked for evidence on: Cardiovascular disease (CVD), Hyperlipidemia, Hypertriglyceridemia, Heart failure, Hypertension, Premenstrual syndrome (PMS) — 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.

The data we hold on astaxanthin — one of this product's active ingredients — does not establish that it works for the conditions studied (age-related cognitive decline, macular degeneration, aging skin, Alzheimer disease, athletic performance, and carpal tunnel syndrome). We have no effectiveness ratings on file for the omega-3 fatty acids or krill oil blend itself in this product.

The evidence, ingredient by ingredient Astaxanthin Krill Oil

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, though long-term safety data are limited. In studies, the most common side effects were abdominal pain, diarrhea, and red-colored stool.

A small number of trial participants taking 6 mg daily experienced increased bowel movements or red stool; at higher doses (40 mg daily), two patients reported severe stomach or abdominal pain. There isn't enough safety data on astaxanthin during pregnancy or while breastfeeding — talk with your doctor or pharmacist before using this product if you're pregnant or nursing.

Side effects, ingredient by ingredient Astaxanthin Krill Oil

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.

Check any medications you take that are processed through your liver's CYP3A4 or CYP2B6 pathways — astaxanthin may theoretically reduce their levels. A pharmacist or doctor can tell you if yours fall into those categories and whether this product is right for you.

Check your own medication Run your meds through the checker above

The bottom line

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

This product's omega-3 fatty acids haven't been checked for drug interactions in our data, but astaxanthin may slow how your liver breaks down certain medications. If you take any prescription drugs, especially those processed through your liver, check your exact medications with the tool on this page and run them by your doctor or pharmacist before starting.

Long-term safety data on astaxanthin are limited, so it's worth a conversation.

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

Assessment coverage: 1 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jan 23, 2023.

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 NKO Neptune Krill Oil 500 mg, straight from the product label.

Brand Source Naturals
Barcode (UPC) 021078017134
Net contents 60 Softgel(s)
Market status On market
Date entered into DSLD Jan 23, 2023
DSLD ID 273337
Product type Other Combinations
Supplement form Softgel Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
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 NKO Neptune Krill Oil 500 mg by Source Naturals, 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:
2 Softgel(s)
Maximum serving Sizes:
2 Softgel(s)
Servings per container
30
UPC/BARCODE
021078017134
IngredientAmount% DV
Calories10 Calorie(s)--
Total Fat1 Gram(s)2%
Eicosapentaenoic Acid135 mg--
Docosahexaenoic Acid60 mg--
Cholesterol10 mg3%
Total Omega-3 Fatty Acids250 mg--
Astaxanthin360 mcg--
Phospholipids450 mg--
Neptune Krill Oil1 Gram(s)--

Other ingredients: Gelatin, Glycerin, purified Water

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

Neptune Krill Oil NKO Original

NKO is an extract from Antarctic krill that contains cell membrane building blocks: highly unsaturated phospholipids co-functionalized with omega-3 fatty acids (EPA & DHA).

Although beneficial for both men and women, NKO also supports temporary relief of PMS symptoms.

FDA Statement of Identity

Dietary Supplement

Formulation

Supports heart health & cell membrane integrity

Contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, preservatives, or artificial color, flavor or fragrance.

Precautions

Contains shellfish (krill).

Caution: If you are pregnant, may become pregnant, breastfeeding, allergic to shellfish, have a blood coagulation condition or are taking anticoagulants such as warfarin (Coumadin), consult a health care professional before using this product.

Caution: If you are pregnant, may become pregnant, breastfeeding, allergic to shellfish, have a blood coagulation condition or are taking anticoagulants such as warfarin (Coumadin), consult a health care professional before using this product.

Do not use if either tamper-evident seal is broken or missing.

Keep out of the reach of children.

Storage

Store in a cool, dry place.

Suggested/Recommended/Usage/Directions

Suggested Use: 2 softgels daily with a meal.

Brand IP Statement(s)

100% Pure NKO manufactured by AKER BioMarine Antarctic AS.

Copyright SOURCE NATURALS, INC.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

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

See for yourself

NKO Neptune Krill Oil 500 mg by Source Naturals label

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

NKO Neptune 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 NKO Neptune Krill Oil 500 mg by Source Naturals

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Softgel(s) Dosage formSoftgel Capsule Servings per container30 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Astaxanthin

Interacts with
671 drugs
360 mcg per serving

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

Astaxanthin monograph & interactions

Neptune Krill Oil

Interacts with
208 drugs
1 Gram(s) 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...

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

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

Interaction report

NKO Neptune Krill Oil 500 mg by Source Naturals Drug Interactions

Want to check YOUR meds against NKO Neptune 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

Astaxanthin 671
Neptune Krill Oil 208

Individual Drug Interactions

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

2 of the 2 ingredients in NKO Neptune Krill Oil 500 mg interact with drugs. Each result below shows which ingredient is responsible. Astaxanthin Neptune Krill Oil

Each ingredient & the kinds of drugs it affects

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

Astaxanthin2 drug types · 671 drugs

Cytochrome P450 2B6 (Cyp2B6) Substrates

Theoretically, astaxanthin may decrease levels of drugs metabolized by CYP2B6.
In vitro research shows that astaxanthin induces cytochrome CYP2B6 enzyme activity in human hepatocytes. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, astaxanthin may decrease levels of drugs metabolized by CYP3A4.
In vitro research shows that astaxanthin induces CYP3A4 enzyme activity in human hepatocytes. This effect has not been reported in humans.

Likelihood Possible Evidence D
Astaxanthin full monograph & interactions

Neptune 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
Neptune Krill Oil full monograph & interactions
The maker

Brand information

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

Source Naturals

Name
Source Naturals, Inc.
Street Address
P. O. Box 2118
City
Santa Cruz
State
CA
ZipCode
95062
Web Address
www.sourcenaturals.com
Pharmacist Counseling Corner

NKO Neptune Krill Oil 500 mg by Source Naturals: Common Questions

Does NKO Neptune Krill Oil 500 mg by Source Naturals interact with any medications?
Yes. Based on its ingredients, NKO Neptune 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?
NKO Neptune Krill Oil 500 mg contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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.
What are the omega-3s in krill oil, and are they the same as fish oil?
This product contains eicosapentaenoic acid and docosahexaenoic acid — two omega-3 fatty acids from Antarctic krill. They're chemically the same as those in fish oil, but krill delivers them packaged in phospholipids, which some people absorb differently. We don't have effectiveness data for either form in our records.
What's astaxanthin, and why is it in here?
Astaxanthin is a natural reddish pigment from krill that acts as an antioxidant. It's included in this product, but we don't have reliable evidence that it works for the conditions it's been studied for — including aging skin, cognitive decline, and joint issues.
Can I take this if I'm pregnant or breastfeeding?
There isn't enough safety data on astaxanthin during pregnancy or breastfeeding. The data advises against use in both situations. Talk with your doctor or pharmacist about whether this product is right for you.
What side effects might I notice?
Most common are abdominal pain, diarrhea, and red-colored stool (the pigment can tint your stool). These are usually mild, but higher doses can cause more severe stomach pain. If you notice anything unusual, stop and check in with your pharmacist or doctor.
Is this safe to take long-term?
Astaxanthin is generally well tolerated, but long-term safety data are limited. If you're thinking about taking it for months or years, that's a good question to bring to your doctor or pharmacist, especially if you're on other medications.

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

Not sure if NKO Neptune Krill Oil 500 mg is safe with your meds?

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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.

NKO Neptune Krill Oil 500 mg label
Go deeper

The Full Monographs Behind NKO Neptune 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

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 → 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 →
Sources

Sources & How We Checked

NKO Neptune 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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