Smartweed + Warfarin Sodium
Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.
Smartweed has a moderate interaction with Warfarin Sodium. Smartweed contains vitamin K. Concomitant use of smartweed might decrease the anticoagulant effects of warfarin, a vitamin K antagonist.
Read the full interaction reportSmartweed and Warfarin Sodium
Here is the interaction we found between these two, with the evidence behind it.
WARFARIN (Coumadin)
Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
Here's the simple version: warfarin works by blocking vitamin K, which is what your body uses to make clots. Smartweed naturally contains some vitamin K, so taking a lot of it could nudge your levels up and make warfarin work a little less than usual. In plain terms, that could mean your blood thins less than your doctor wants, and your INR might drift down, which raises the risk of a clot forming.
Now, the honest part: this is a theoretical concern based on smartweed's vitamin K content, not strong human studies. The bigger issue with warfarin is staying consistent. Sudden changes, up or down, are what throws your INR off. So don't start or stop smartweed on your own. Just give your pharmacist or doctor a heads-up so they can check your INR if needed.
- Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
What These Ratings Mean
Every interaction above is graded three ways — here’s the key to each label.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
- ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
- PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
- UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
- AHigh-quality meta-analysis (quantitative systematic review).
- BCase-control study.
- CConsensus.
- DAnecdotal evidence.
These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.
Smartweed Also Interacts With Other Medications
Smartweed has 1 moderate known drug interaction in our database — the Warfarin Sodium one above is one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Smartweed
We haven’t checked that one against Smartweed yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Smartweed. Pick one to open its full report.
Questions About Smartweed or Warfarin Sodium
These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Smartweed or Warfarin Sodium, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:
- Do Pomegranate Supplements Raise Potassium With Kidney Disease? ›
- Does Ginger Water Interfere With Amoxicillin-Clavulanate? ›
- Can You Take Nattokinase With a 40 mg Statin? ›
Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.
See Every Supplement That Interacts With Warfarin Sodium
This page covers Smartweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Warfarin Sodium page lists 361 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Alfalfa (major), American Ginseng (major), Beer (major) and Cannabis (major).
Taking Smartweed as Part of a Dietary Supplement Product? Check It for Interactions
We hold 4 real supplement products containing Smartweed, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Smartweed. Your product may carry other ingredients that interact with Warfarin Sodium too, on top of Smartweed — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Smartweed and Warfarin Sodium Sit Against Everything Else
Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.
#607 of 1,452 supplements looked up here in the last 7 days
#28 of 2,830 medications looked up here in the last 7 days
Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.
About Smartweed
What is Smartweed?
- Digestive upset
- Minor skin irritation
- Heavy menstrual bleeding (traditional)
- Wound and bleeding (traditional topical use)
- Antioxidant and anti-inflammatory support
Smartweed (Persicaria hydropiper) is a peppery wetland plant with a long history in traditional medicine for digestive complaints, bleeding, and skin problems. Modern human studies are very limited, so its benefits are not well proven. Because safety data are thin, it's best to use cautiously and avoid it during pregnancy and breastfeeding.
About Warfarin
What Is Warfarin Used For?
Brand names: Coumadin, Panwarfin, Sofarin
Warfarin helps prevent and treat harmful blood clots. The label lists these uses for both Warfarin Sodium tablets and Jantoven tablets:
- Preventing and treating venous thrombosis (clots in the veins) and pulmonary embolism (clots in the lungs).
- Preventing and treating clot-related complications of atrial fibrillation and/or heart valve replacement.
- Lowering the risk of death, another heart attack, and clot-related events such as stroke after a heart attack.
Warfarin does not dissolve a clot that has already formed. It helps stop the clot from growing and prevents further clot-related complications.
Other Drugs & Smartweed
Browse every other medication we’ve checked against Smartweed — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
1 interaction
No interaction 2,828 drugs checked — show the list
We also checked Smartweed against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Ivermectin ›
- Abemaciclib ›
- Testosterone ›
- Losartan Potassium ›
- Sertraline ›
- Rosuvastatin ›
- Acetaminophen ›
- Aspirin ›
- Metoprolol ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Rivaroxaban ›
- Isotretinoin ›
- Tirzepatide ›
- Ibuprofen ›
- Levothyroxine, Liothyronine ›
- Amlodipine Besylate ›
- Docusate ›
- Metformin ›
- Amitriptyline ›
- Prednisone ›
- Methamphetamine ›
- Tadalafil ›
- Semaglutide ›
- Lisdexamfetamine ›
- Amphetamine ›
- Sumatriptan ›
- Hydroxyurea ›
- Propranolol ›
- Valacyclovir ›
- Amoxicillin ›
- Lisinopril ›
- Methotrexate ›
- Bupropion ›
- Azithromycin ›
- Fluoxetine ›
- Doxycycline ›
- Pregabalin ›
- Gabapentin ›
- Acetaminophen, Aspirin, Caffeine ›
- Dextroamphetamine ›
- Naproxen ›
- Lamotrigine ›
- Bendamustine ›
- Clonazepam ›
- Quetiapine ›
- Acyclovir ›
- Buspirone ›
- Duloxetine ›
- Omeprazole ›
- Letrozole ›
- Citalopram ›
- Methylene Blue ›
- Ciprofloxacin ›
- Acetaminophen, Codeine ›
Showing the 60 most looked-up of 2,828 medications checked with no known interaction — see the full Smartweed list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
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
Taking Smartweed and Warfarin Sodium Together: Common Questions
Can you take Smartweed with Warfarin Sodium?
How serious is the Smartweed and Warfarin Sodium interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.