Vitamin K-2 100 mcg Ingredients & Drug Interactions
by NOW
What is this page for?
First and foremost: checking Vitamin K-2 100 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
Vitamin K-2 100 mcg is a dietary supplement by NOW with 2 active ingredients. Its ingredients are commonly taken for supporting normal blood clotting, bone health, heart and vascular health.Based on those ingredients, 583 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Alfalfa powder, Vitamin K2. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Vitamin K-2 100 mcg by NOW
Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin K-2 100 mcg by NOW — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Vitamin K-2 100 mcg by NOW
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.
What’s inside
Full disclosure
This product contains 2 active ingredients: vitamin K2 (the menaquinone form of vitamin K) and alfalfa powder. Vitamin K2 is a fat-soluble nutrient involved in blood clotting and bone health.
Alfalfa is a plant extract that has been used traditionally in herbal medicine. The capsule also contains several inactive ingredients — hypromellose, ascorbyl palmitate, rice flour, and silicon dioxide — which are binders, preservatives, and fillers.
Does it work?
Strong evidence
Vitamin K2 is rated effective for correcting vitamin K deficiency states, including hypoprothrombinemia (low clotting factors) and hemorrhagic disease. It's also rated possibly effective for osteoporosis.
Alfalfa, by contrast, has insufficient reliable evidence for any of the conditions it's been studied for — diabetes, indigestion, high cholesterol, and menopausal symptoms — so we can't say whether it works for any of those uses based on the data we hold.
How safe is it?
Well-documented data
Vitamin K taken by mouth is generally well tolerated. The most common side effects are mild gastrointestinal ones: nausea, diarrhea, and stomach upset.
The safety data rates vitamin K as likely safe in pregnancy and lactation. Alfalfa is generally considered safe in small food amounts, but the safety data advises against supplement doses during pregnancy because alfalfa has estrogen-like activity.
There isn't enough reliable safety data for supplement use while breastfeeding, so talk with your provider. Common side effects from alfalfa include bloating, gas, diarrhea, and loose stools.
Rarely, chronic heavy use has been linked to a lupus-like syndrome.
Meds to double-check
Major interaction found
Most important: if you take warfarin (Coumadin) or any blood thinner, check with your doctor before starting this product — vitamin K can reverse its effects. Also double-check if you take birth control pills, estrogen therapy, diabetes medications, immunosuppressants, or any light-sensitizing drugs, as alfalfa in this product may interact with those.
The bottom line
Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Major medication interactions have been identified, and safety information is well characterized.
This product is mainly useful if you have a vitamin K deficiency or related clotting disorder — but if you take warfarin, it's off the table without your doctor's go-ahead. The alfalfa component adds interactions with birth control, diabetes drugs, and estrogen therapy.
If you're pregnant or breastfeeding, talk with your pharmacist before taking it. Run your medications through the checker on this page.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jul 25, 2024.
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
General information
Key facts about Vitamin K-2 100 mcg, straight from the product label.
| Brand | NOW |
|---|---|
| Barcode (UPC) | 733739009913 |
| Net contents | 250 Veg Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Jul 25, 2024 |
| DSLD ID | 315729 |
| Product type | Botanical With Nutrients |
| Supplement form | Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, Women (not pregnant or lactating), Halal |
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 Vitamin K-2 100 mcg by NOW, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Vitamin K2 | 100 mcg | -- |
| Alfalfa powder | 250 mg | -- |
Other ingredients: Hypromellose, Ascorbyl Palmitate, Rice Flour, Silicon Dioxide
Tap any ingredient to jump to its full detail below.
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.
Suggested/Recommended/Usage/Directions
Suggested Usage: Take 1 capsule daily with a meal.
Formula
Although Vitamin K is historically known for its role in normal blood clotting function, we now know that Vitamin K is also essential to bone, cardiovascular, and nervous system health. As a biologically active form of Vitamin K, K-2 is important for the formation of healthy, strong bone matrix. Vitamin K's role in arterial health revolves around its ability to support proper calcium metabolism in vascular structures.
Menaquinone-4 (MK-4)
Triangle K (Kosher)
Crescent H (Halal)
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.
Precautions
Caution: For adults only. Keep out of reach of children.
Do not use if pregnant, nursing, or allergic or contraindicated to aspirin. Consult physician if taking medication (especially blood thinners such as warfarin, Coumadin, heparin and aspirin) or have a medical condition.
Do not use if pregnant, nursing or allergic or contraindicated to aspirin.
Discontinue use two weeks prior to surgery or if stomach upset occurs.
Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.
Formulation
Supports Bone Health Biologically Active Form Supports Proper Calcium Metabolism
Non-GMO
Vegetarian/Vegan
Made and quality tested in the USA with globally sourced ingredients. Natural color variation may occur in this product.
Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, tree nut or sesame ingredients.
Seals/Symbols
Triangle K (Kosher)
Crescent H (Halal) GMP Quality Assured
FDA Statement of Identity
A Dietary Supplement
General Statements
Vitamins Family owned since 1968.
This bottle is made from 100% PCR (post-consumer recycled) resin.
Storage
Store in a cool, dry place after opening.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Vitamin K-2 100 mcg by NOW label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in Vitamin K-2 100 mcg by NOW
These are the 2 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Veg Capsule(s) Dosage formCapsule Servings per container250 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.
Vitamin K2
Interacts with2 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 suppl...
Vitamin K2 monograph & interactionsAlfalfa powder
Interacts with583 drugs
Alfalfa is a nutrient-rich legume that people use for high cholesterol, menopause symptoms, and general wellness, but solid human evidence for most of...
Alfalfa powder monograph & interactionsOther (inactive) ingredients: Hypromellose, Ascorbyl Palmitate, Rice Flour, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.
Vitamin K-2 100 mcg by NOW Drug Interactions
HelloPharmacist Interaction Report
NOW's Vitamin K-2 100 mcg contains two active ingredients — vitamin K2 and alfalfa powder — and both interact with medications you may be taking.
Read the full breakdown — every affected drug type, severity by severity
The most serious concern is warfarin (Coumadin), a blood thinner. Both vitamin K2 and alfalfa contain vitamin K, which can directly reverse warfarin's effects and reduce how well it prevents blood clots.
This is a Major interaction — if you take warfarin, do not use this product without talking to your doctor first.
Alfalfa also has moderate interactions with several other drug types. It may interfere with birth control pills and estrogen therapy because it contains compounds with estrogen-like activity.
It might also increase the blood-sugar-lowering effect of diabetes medications, raising the risk of low blood sugar (hypoglycemia). Additionally, alfalfa may reduce how well immunosuppressants work and could theoretically add to the photosensitivity risk of certain light-sensitive drugs.
Vitamin K2 itself has no other documented interactions beyond warfarin. Altogether, these interactions span 577 individual medications.
Use the medication checker below to see if any of your prescriptions are affected.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Vitamin K-2 100 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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Vitamin K-2 100 mcg interact with 583 drugs. Click any drug to see the details.
2 of the 2 ingredients in Vitamin K-2 100 mcg interact with drugs. Each result below shows which ingredient is responsible. Alfalfa powder Vitamin K2
WarfarinWarfarin
How Warfarin interacts with Vitamin K-2 100 mcg — through 2 ingredients. Tap an ingredient for the detail:
Alfalfa PowderWarfarin (coumadin) Major
Interaction Summary
Theoretically, alfalfa might reduce the anticoagulant activity of warfarin.
Read the full Alfalfa Powder + Warfarin interactionVitamin K2Warfarin (coumadin) Major
Interaction Summary
Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Read the full Vitamin K2 + Warfarin interactionWarfarin SodiumCoumadin, Panwarfin, Sofarin
How Warfarin Sodium interacts with Vitamin K-2 100 mcg — through 2 ingredients. Tap an ingredient for the detail:
Alfalfa PowderWarfarin (coumadin) Major
Interaction Summary
Theoretically, alfalfa might reduce the anticoagulant activity of warfarin.
Read the full Alfalfa Powder + Warfarin Sodium interactionVitamin K2Warfarin (coumadin) Major
Interaction Summary
Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Read the full Vitamin K2 + Warfarin Sodium interaction6-mercaptopurinePurinethol
How 6-mercaptopurine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderImmunosuppressants Moderate
Interaction Summary
Theoretically, alfalfa might decrease the efficacy of immunosuppressive therapy.
Read the full Alfalfa Powder + 6-mercaptopurine interactionAbrocitinibCibinqo
How Abrocitinib interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderImmunosuppressants Moderate
Interaction Summary
Theoretically, alfalfa might decrease the efficacy of immunosuppressive therapy.
Read the full Alfalfa Powder + Abrocitinib interactionAcarboseGlucobay, Prandase, Precose
How Acarbose interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, alfalfa might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Read the full Alfalfa Powder + Acarbose interactionAcepromazineAtravet
How Acepromazine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acepromazine interactionAcetaminophen, Brompheniramine, PhenylpropanolamineDimetapp Cold and Flu
How Acetaminophen, Brompheniramine, Phenylpropanolamine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Brompheniramine, Phenylpropanolamine interactionAcetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound
How Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interactionAcetaminophen, Chlorpheniramine Maleate, Dextromethorphan HbrVicks Formula 44M Cough, Cold & Flu Relief
How Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interactionAcetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex
How Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interactionAcetaminophen, Chlorpheniramine, DextromethorphanCoricidin II Extra Strength Cold and Flu
How Acetaminophen, Chlorpheniramine, Dextromethorphan interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Dextromethorphan interactionAcetaminophen, Chlorpheniramine, Dextromethorphan HydrobromideCoricidin HBP Maximum Strength Flu
How Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interactionAcetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief
How Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interactionAcetaminophen, Chlorpheniramine, Dextromethorphan, PseudoephedrineChildren's Tylenol Cold Plus Cough, Tylenol Cold Ex Strength
How Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine interactionAcetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, SalicylamideRhinogesic GG
How Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, Salicylamide interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, Salicylamide interactionAcetaminophen, Chlorpheniramine, PhenylephrineAlka-Seltzer PLUS, Histex SR, Protid
How Acetaminophen, Chlorpheniramine, Phenylephrine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Phenylephrine interactionAcetaminophen, Chlorpheniramine, Phenylephrine, SalicylamideRhinogesic, Rhinogesic JR
How Acetaminophen, Chlorpheniramine, Phenylephrine, Salicylamide interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Phenylephrine, Salicylamide interactionAcetaminophen, Chlorpheniramine, PhenylpropanolamineAlumadrine, Conex, Sinadrin Max Strength, Sinulin
How Acetaminophen, Chlorpheniramine, Phenylpropanolamine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Phenylpropanolamine interactionAcetaminophen, Chlorpheniramine, Phenylpropanolamine, OpiumHista-Derfule
How Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Opium interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Opium interactionAcetaminophen, Chlorpheniramine, Phenylpropanolamine, PhenyltoloxamineNorel Plus
How Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Phenyltoloxamine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Phenylpropanolamine, Phenyltoloxamine interactionAcetaminophen, Chlorpheniramine, PseudoephedrineAlka-Seltzer PLUS Liquid Gels, Children's Tylenol Cold, Codimal, Comtrex, Extra Strength Tylenol Allergy Sinus, Lorsin +3 more
How Acetaminophen, Chlorpheniramine, Pseudoephedrine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Chlorpheniramine, Pseudoephedrine interactionAcetaminophen, Dexbrompheniramine, PseudoephedrineSinadrin Plus
How Acetaminophen, Dexbrompheniramine, Pseudoephedrine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Dexbrompheniramine, Pseudoephedrine interactionAcetaminophen, DiphenhydramineTylenol PM, Tylenol PM Ex Strength
How Acetaminophen, Diphenhydramine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Diphenhydramine interactionAcetaminophen, Diphenhydramine, PseudoephedrineChildren's Tylenol Allergy, Cold Control, Contac Night Allergy Relief
How Acetaminophen, Diphenhydramine, Pseudoephedrine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Diphenhydramine, Pseudoephedrine interactionAcetaminophen, IbuprofenCombogesic
How Acetaminophen, Ibuprofen interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Ibuprofen interactionAcetaminophen, Phenylephrine, ChlorpheniramineSuper Cold Tabs
How Acetaminophen, Phenylephrine, Chlorpheniramine interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetaminophen, Phenylephrine, Chlorpheniramine interactionAcetazolamideAk-Zol, Diamox
How Acetazolamide interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetazolamide interactionAcetohexamideDymelor
How Acetohexamide interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs, Antidiabetes Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acetohexamide interactionAcitretinSoriatane
How Acitretin interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderPhotosensitizing Drugs Moderate
Interaction Summary
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Read the full Alfalfa Powder + Acitretin interactionAdalimumabHumira
How Adalimumab interacts with Vitamin K-2 100 mcg — through 1 ingredient. Tap an ingredient for the detail:
Alfalfa PowderImmunosuppressants Moderate
Interaction Summary
Theoretically, alfalfa might decrease the efficacy of immunosuppressive therapy.
Read the full Alfalfa Powder + Adalimumab interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Vitamin K-2 100 mcg 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.
Alfalfa powder
Warfarin (Coumadin)
Theoretically, alfalfa might reduce the anticoagulant activity of warfarin.
Alfalfa contains a large amount of vitamin K. This could theoretically interfere with the activity of warfarin.
Antidiabetes Drugs
Theoretically, alfalfa might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research suggests that alfalfa decreases blood sugar in diabetic mice. Also, in one case report, a diabetic patient experienced hypoglycemia after consuming alfalfa extract. Monitor blood glucose levels closely. Dose adjustments might be necessary.
Contraceptive Drugs
Theoretically, alfalfa might interfere with the activity of contraceptive drugs.
Alfalfa contains coumestrol, a phytoestrogen, and isoflavonoids, which have estrogenic effects.
Estrogens
Theoretically, alfalfa might interfere with hormone therapy.
Alfalfa contains coumestrol, a phytoestrogen, and isoflavonoids, which have estrogenic effects.
Immunosuppressants
Theoretically, alfalfa might decrease the efficacy of immunosuppressive therapy.
In vitro research and human case reports suggest that alfalfa may have immunostimulant effects.
Photosensitizing Drugs
Theoretically, concomitant use of alfalfa with photosensitizing drugs might have additive effects.
Animal research suggests that excessive doses of alfalfa may increase photosensitivity, possibly due to its chlorophyll content. It is unclear if this effect would be clinically relevant in humans.
Vitamin K2
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.
Brand information
Manufacturer and brand details for Vitamin K-2 100 mcg, from the product label.
NOW
See all NOW products- Name
- NOW FOODS
- Street Address
- 395 S. Glen Ellyn Rd.
- City
- Bloomingdale
- State
- IL
- ZipCode
- 60108
- Web Address
- nowfoods.com
Vitamin K-2 100 mcg by NOW: Common Questions
Does Vitamin K-2 100 mcg by NOW interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take this if I'm pregnant?
What side effects might I notice?
Is this product actually effective for bone health?
Can I take this with my diabetes medication?
Does this product contain any fillers or extra ingredients?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Vitamin K-2 100 mcg is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
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.
The Full Monographs Behind Vitamin K-2 100 mcg’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Vitamin K
Interacts with 2 drugsVitamin 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 → Herb & supplement monographAlfalfa
Interacts with 583 drugsAlfalfa is a nutrient-rich legume that people use for high cholesterol, menopause symptoms, and general wellness, but solid human evidence for most of these uses is limited. It is best avoid...
Read the full Alfalfa monograph →Sources & How We Checked
Vitamin K-2 100 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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 43 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
- McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
- 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.
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