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Dietary supplement

Mega Vitamin K2 45,000 mcg Ingredients & Drug Interactions

by Life Extension

Mega Vitamin K2 45,000 mcg label
See full label image
Capsule Category: Vitamin
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Mega Vitamin K2 45,000 mcg 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: Major

Mega Vitamin K2 45,000 mcg is a dietary supplement by Life Extension with 1 active ingredient. Its ingredients are commonly taken for supporting normal blood clotting, bone health, heart and vascular health.Based on those ingredients, 2 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Vitamin K2. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Mega Vitamin K2 45,000 mcg by Life Extension

Ask about any prescription or over-the-counter medication and we check it for interactions with Mega Vitamin K2 45,000 mcg by Life Extension — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Mega Vitamin K2 45,000 mcg by Life Extension

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 Jul 11, 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 1 of its 1 active ingredient.
  • “Vitamin K2” is listed as a grouped ingredient — the label gives one combined amount (45,000 mcg) without saying how much of each component you get.

This product contains one active ingredient: menaquinone-4, a form of vitamin K2. Vitamin K plays a key role in blood clotting and also supports bone and cardiovascular health.

The capsule also includes microcrystalline cellulose, gelatin, stearate, and silica as inactive ingredients (binders and flow agents).

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: High potency for strong bones.
  • We looked for evidence on: Osteoporosis, Bone density, Bone strength, Bone mineralization.
  • The strongest evidence on file: Vitamin K is rated "Possibly Effective" for Osteoporosis (Natural Medicines).

Menaquinone-4 is rated effective for correcting vitamin K deficiency conditions — including low levels of vitamin K-dependent clotting factors and hemorrhagic disease (bleeding disorders caused by inadequate clotting). It's also rated effective for managing warfarin anticoagulation when vitamin K supplementation is medically necessary.

For bone health, the evidence is rated possibly effective for osteoporosis, meaning the data suggests a benefit but isn't yet conclusive.

The evidence, ingredient by ingredient Vitamin K

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.

Vitamin K taken by mouth is generally well tolerated in healthy people at dietary amounts and most supplement doses. The most common side effects are mild gastrointestinal — nausea, stomach upset, abdominal pain, and diarrhea.

Serious side effects are rare. The safety data advises checking with your doctor before taking vitamin K supplements, even though dietary amounts are considered fine.

Vitamin K is rated likely safe in pregnancy and lactation.

Side effects, ingredient by ingredient Vitamin K

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Vitamin K.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 2 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 if you use warfarin or any other blood thinner (anticoagulant). Vitamin K can reduce their effectiveness and raise your clot risk.

Altogether, these interactions span 2 individual medications.

Check your own medication Run your meds through the checker above

The bottom line

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

This supplement makes sense for people with documented vitamin K deficiency or those whose doctors have prescribed it to manage warfarin therapy. If you take any blood thinner, get pharmacist or physician clearance before starting — this dose is substantial enough to interfere with your medication.

Anyone else should talk with their pharmacist about whether supplementing is right for them.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Mar 25, 2025.

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 Mega Vitamin K2 45,000 mcg, straight from the product label.

Brand Life Extension
Barcode (UPC) 737870241737
Net contents 30 Capsule(s)
Market status On market
Date entered into DSLD Mar 25, 2025
DSLD ID 328571
Product type Vitamin
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Mega Vitamin K2 45,000 mcg by Life Extension, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
30
UPC/BARCODE
737870241737
IngredientAmount% DV
Vitamin K245000 mcg37500%
Menaquinone-445 mg--

Other ingredients: Microcrystalline Cellulose, Gelatin, Stearate, Silica

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.
General Statements

Scan for product info

Suggested/Recommended/Usage/Directions

Directions: Take one (1) capsule daily with food, or as recommended by a healthcare practitioner.

Precautions

Caution: If you are taking Warfarin (Coumadin) or related medications, consult your heatlhcare practitioner before taking this product.

Warnings: Keep out of reach of children.

Do not exceed recommended dose. Do not purchase if outer seal is broken or damaged.

When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating.

To report a serious adverse event or obtain product information, contact 1-866-280-2852.

Read the entire label and follow the directions carefully prior to use.

Formulation

High potency for strong bones

Gluten Free Non GMO LE Certified

Seals/Symbols

Non GMO LE Certified

Formula

45,000 mcg of MK4

FDA Statement of Identity

Dietary Supplement

Storage

Store tightly closed in a cool, dry place.

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

Mega Vitamin K2 45,000 mcg by Life Extension label

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

Mega Vitamin K2 45,000 mcg 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 Mega Vitamin K2 45,000 mcg by Life Extension

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

Vitamin K2

Interacts with
2 drugs
45000 mcg per serving

Vitamin K is an essential nutrient your body needs for normal blood clotting and to support healthy bones. Most people get enough from food, but suppl...

Vitamin K2 monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Gelatin, Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Mega Vitamin K2 45,000 mcg by Life Extension Drug Interactions

Want to check YOUR meds against Mega Vitamin K2 45,000 mcg?

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
2Drugs
2 Major

Ingredients driving the most interactions

Vitamin K2 2

Individual Drug Interactions

The ingredients in Mega Vitamin K2 45,000 mcg interact with 2 drugs. Click any drug to see the details.

1 of the 1 ingredient in Mega Vitamin K2 45,000 mcg interact with drugs. Each result below shows which ingredient is responsible. Vitamin K2

Each ingredient & the kinds of drugs it affects

For each ingredient in Mega Vitamin K2 45,000 mcg 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.

Vitamin K21 drug type · 2 drugs

Warfarin (Coumadin)

Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Vitamin K antagonizes the effects of warfarin. Excessive vitamin K intake, either from supplements or from changes in the diet, can reduce the anticoagulant effect of warfarin.

Likelihood Likely Evidence C
Vitamin K2 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Mega Vitamin K2 45,000 mcg, from the product label.

Life Extension

See all Life Extension products
Name
Quality Supplements and Vitamins, Inc.
City
Ft. Lauderdale
State
FL
ZipCode
33309
Phone Number
1-866-280-2852
Web Address
LifeExtension.com
Pharmacist Counseling Corner

Mega Vitamin K2 45,000 mcg by Life Extension: Common Questions

Does Mega Vitamin K2 45,000 mcg by Life Extension interact with any medications?
Yes. Based on its ingredients, Mega Vitamin K2 45,000 mcg has a known interaction with 2 medications, including 2 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Mega Vitamin K2 45,000 mcg 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 this if I'm on warfarin?
No — not without your doctor's approval. Vitamin K directly counteracts warfarin and can lower its blood-thinning effect, raising your clot risk. Talk to your prescriber before adding any vitamin K supplement.
What side effects should I expect?
Most people have no issues, but some experience mild stomach upset — nausea, abdominal pain, or diarrhea. Serious side effects are rare. If these symptoms persist or worsen, let us know.
Is this safe during pregnancy?
Yes — vitamin K is rated likely safe in pregnancy and while breastfeeding. That said, talk with your OB or midwife before starting any new supplement during pregnancy.
What's menaquinone-4, and why is it in this product?
Menaquinone-4 is a form of vitamin K2. It supports blood clotting, bone strength, and cardiovascular health. This supplement delivers a high dose of it if your diet is low in vitamin K.
Do I need a prescription for this?
No — this is sold over the counter. But if you take any prescription medication, especially blood thinners, run it past your pharmacist or doctor before you start.

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

Not sure if Mega Vitamin K2 45,000 mcg 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.

Mega Vitamin K2 45,000 mcg label
Go deeper

The Full Monographs Behind Mega Vitamin K2 45,000 mcg’s Ingredients

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

Herb & supplement monograph

Vitamin K

Interacts with 2 drugs

Vitamin K is an essential nutrient your body needs for normal blood clotting and to support healthy bones. Most people get enough from food, but supplements are sometimes used for deficiency...

Read the full Vitamin K monograph →
Sources

Sources & How We Checked

Mega Vitamin K2 45,000 mcg'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 11 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.

Vitamin K 11 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  3. Crowther MA, Ageno W, Garcia D, et al. Oral vitamin K versus placebo to correct excessive anticoagulation in patients receiving warfarin: a randomized trial. Ann Intern Med. 2009;150(5):293-300. PubMed
  4. Dietary vitamin K guidance: an effective strategy for stable control of oral anticoagulation? Nutr Rev. 2010;68(3):178-81. PubMed
  5. Kim JS, Nafziger AN, Gaedigk A, et al. Effects of oral vitamin K on S- and R-warfarin pharmacokinetics and pharmacodynamics: enhanced safety of warfarin as a CYP2C9 probe. J Clin Pharmacol. 2001 Jul;41(7):715-22. PubMed
  6. Riegert-Johnson, D. L. and Volcheck, G. W. The incidence of anaphylaxis following intravenous phytonadione (vitamin K1): a 5-year retrospective review. Ann.Allergy Asthma Immunol. 2002;89(4):400-406. PubMed
  7. Dezee, K. J., Shimeall, W. T., Douglas, K. M., Shumway, N. M., and O'malley, P. G. Treatment of excessive anticoagulation with phytonadione (vitamin K): a meta-analysis. Arch.Intern.Med. 2-27-2006;166(4):391-397. DOI
  8. Dentali, F., Ageno, W., and Crowther, M. Treatment of coumarin-associated coagulopathy: a systematic review and proposed treatment algorithms. J.Thromb.Haemost. 2006;4(9):1853-1863. PubMed
  9. Caluwé R, Vandecasteele S, Van Vlem B, Vermeer C, De Vriese AS. Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding study. Nephrol Dial Transplant. 2014;29(7):1385-90.
  10. Huang ZB, Wan SL, Lu YJ, Ning L, Liu C, Fan SW. Does vitamin K2 play a role in the prevention and treatment of osteoporosis for postmenopausal women: a meta-analysis of randomized controlled trials. Osteoporos Int. 2015;26(3):1175-86. PubMed
  11. Hunnali CR, Devi U, Kitchanan S, Sethuraman G. Three Different Regimens for Vitamin K Birth Prophylaxis in Infants Born Preterm: A Randomized Clinical Trial. J Pediatr 2023;255:98-104. PubMed

See these in context on the Vitamin K 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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