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Dietary supplement

K2 100 mcg Ingredients & Drug Interactions

by Swanson

K2 100 mcg label
See full label image
Softgel 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 K2 100 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

K2 100 mcg is a dietary supplement by Swanson 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 K2 100 mcg by Swanson

Ask about any prescription or over-the-counter medication and we check it for interactions with K2 100 mcg by Swanson — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of K2 100 mcg by Swanson

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

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.
  • No proprietary blends here — you can verify the dose of every single component.

This product has one active ingredient: vitamin K2 at 100 micrograms per softgel capsule. Vitamin K is a fat-soluble vitamin your body uses to help blood clot and to support bone and heart health.

The softgel also contains inactive ingredients — sunflower seed oil, gelatin, glycerin, beeswax, dibasic calcium phosphate, sunflower lecithin, carob color, and purified water — which serve as the capsule and base.

Does it work?

Strong 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

This product doesn't appear to be marketed for a specific use, so we graded Vitamin K's overall clinical evidence instead.

Strong

Strong clinical evidence supports Vitamin K for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Hemorrhagic disease — rated "Effective" (Natural Medicines).
  • On file: Hypoprothrombinemia — rated "Effective" (Natural Medicines).
  • On file: Warfarin anticoagulation — rated "Effective" (Natural Medicines).
  • On file: Vitamin K-dependent clotting factors deficiency (VKCFD) — rated "Effective" (Natural Medicines).
  • On file: Osteoporosis — rated "Possibly Effective" (Natural Medicines).

Vitamin K2 is rated Effective for correcting vitamin K deficiency-related bleeding disorders — hypoprothrombinemia (a clotting factor shortage), vitamin K-dependent clotting factor deficiency, and hemorrhagic disease. It's also rated Effective for restoring the anticoagulation effect of warfarin when vitamin K intake has interfered with it.

For osteoporosis, the evidence is rated Possibly Effective, so the science is still building but shows some promise.

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.

Taken by mouth, vitamin K is generally well tolerated. The most common side effects are mild: diarrhea, nausea, abdominal pain, and stomach upset — and only a small number of people experience these.

Vitamin K is rated Likely Safe during pregnancy and lactation. For supplements specifically, though, the safety data advises checking with your doctor first; normal dietary amounts are fine, but supplementing is a choice to discuss with your healthcare provider.

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 with your doctor or pharmacist if you take warfarin (Coumadin) or any other blood thinner (anticoagulant). Vitamin K can reduce how well these medications prevent clots.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Major medication interactions have been identified, and safety information is well characterized.

K2 is a straightforward single-ingredient supplement for supporting bone and cardiovascular health and for correcting vitamin K deficiency. If you take warfarin or any blood thinner, you must talk with your doctor or pharmacist before starting this product — it can interfere with how your medication works.

For everyone else, discuss supplementing with your own healthcare provider to make sure it's right for you.

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 Jun 16, 2022.

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 K2 100 mcg, straight from the product label.

Brand Swanson
Barcode (UPC) 087614026725
Net contents 30 Softgel(s)
Market status On market
Date entered into DSLD Jun 16, 2022
DSLD ID 266881
Product type Vitamin
Supplement form Softgel Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 K2 100 mcg by Swanson, 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)
Servings per container
30
UPC/BARCODE
087614026725
IngredientAmount% DV
Vitamin K2100 mcg--

Other ingredients: Sunflower Seed Oil, Gelatin, Glycerin, Beeswax, Dibasic Calcium Phosphate, Sunflower Lecithin, Carob color, 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.
General Statements

visit our website at www.swanson.com

Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, take one softgel per day with water.

Precautions

Warning: For adults only.

Consult your healthcare provider before use if you are pregnant or nursing, taking medication, especially blood-thinning medication, or have a medical condition.

Keep out of reach of children.

Do not use if seal is broken.

Contains sulfites.

Storage

Store in a cool, dry place. Do not refrigerate.

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.

Formula

Natural Vitamin K2

Formulation

Bone and Cardiovascular health

100 mcg per softgel

FDA Statement of Identity

Vitamin Supplement

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

See for yourself

K2 100 mcg by Swanson label

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

K2 100 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 K2 100 mcg by Swanson

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 Servings per container30 Amounts shown are per serving.

Vitamin K2

Interacts with
2 drugs
100 mcg per serving Form: Menaquinone-7

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: Sunflower Seed Oil, Gelatin, Glycerin, Beeswax, Dibasic Calcium Phosphate, Sunflower Lecithin, Carob color, Purified Water. These complete the product’s ingredient list but are not active constituents.

Interaction report

K2 100 mcg by Swanson Drug Interactions

Want to check YOUR meds against K2 100 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 K2 100 mcg interact with 2 drugs. Click any drug to see the details.

1 of the 1 ingredient in K2 100 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 K2 100 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 K2 100 mcg, from the product label.

Swanson

See all Swanson products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
swanson.com
Pharmacist Counseling Corner

K2 100 mcg by Swanson: Common Questions

Does K2 100 mcg by Swanson interact with any medications?
Yes. Based on its ingredients, K2 100 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?
K2 100 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.
Will this interact with my medications?
The main concern is warfarin and other blood thinners — vitamin K can reduce their effect. Use the search tool on this page to check your exact medications, and talk with your pharmacist or doctor before starting.
What are the common side effects?
Taken by mouth, vitamin K is generally well tolerated. A small number of people experience mild gastrointestinal side effects like nausea, diarrhea, abdominal pain, or stomach upset.
Is it safe to take during pregnancy or while breastfeeding?
Vitamin K is rated Likely Safe during pregnancy and lactation. Still, supplementing (as opposed to getting it from food) is a decision to make with your doctor or pharmacist, who can give you personalized advice.
What does vitamin K2 do?
Your body uses vitamin K to help blood clot properly and to support bone and heart health. This product is effective for treating vitamin K deficiency and related bleeding disorders, and shows promise for bone health.
Does this product contain any fillers?
Yes — the softgel contains inactive ingredients like sunflower seed oil, gelatin, glycerin, beeswax, and others that make up the capsule and base.

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

Not sure if K2 100 mcg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.

K2 100 mcg label
Go deeper

The Full Monographs Behind K2 100 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

K2 100 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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