Drug & supplement interaction

Yellow Dock + Warfarin

Warfarin brand name: Warfarin.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Yellow Dock has a moderate interaction with Warfarin. Theoretically, the laxative effects of yellow dock might increase the effects of warfarin, including the risk of bleeding.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Yellow Dock and Warfarin

Here is the interaction we found between these two, with the evidence behind it.

Moderate

WARFARIN (Coumadin)

Theoretically, the laxative effects of yellow dock might increase the effects of warfarin, including the risk of bleeding.
The anthraquinones in yellow dock have a mild stimulant laxative effect. Consuming excessive amounts can cause diarrhea. Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to know about pairing yellow dock with your warfarin. Yellow dock acts as a mild stimulant laxative because of its anthraquinone compounds, similar to senna. If you take enough to cause loose stools or diarrhea, that can actually nudge your warfarin to work a little harder, pushing your INR up and raising your risk of bleeding (think easy bruising, nosebleeds, bleeding gums, or blood in your stool or urine).

This is a theoretical concern based on how these things work, not something proven in studies, so I don't want you to panic. But warfarin is a finicky drug where small shifts matter. If you're thinking about using yellow dock, please check with your doctor or pharmacist first, and watch for any unusual bleeding.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  3. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • 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.
Evidence the quality of the studies behind the rating (graded A–D)
  • 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.

Keep it in perspective

Yellow Dock Also Interacts With Other Medications

Yellow Dock has 76 major, 1 moderate known drug interactions in our database — the Warfarin one above is one of them. If you take anything else, check it against the full list below.

Major 76 Moderate 1 No known interaction 2,753 (incl. Warfarin)
Taking anything else?

Check Another of Your Medications Against Yellow Dock

Covers the 2,830 medications we’ve checked against Yellow Dock. Pick one to open its full report.

From our Q&A

Questions About Yellow Dock or Warfarin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Yellow Dock or Warfarin, 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:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Warfarin

This page covers Yellow Dock only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Warfarin 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).

By severity: 16 major · 301 moderate · 44 minor.

From our pharmacist’s overview on the Warfarin page

“People take warfarin to prevent dangerous clots, and many are the same people reaching for glucosamine for sore joints or a multivitamin containing vitamin K, which makes this a list that deserves genuine respect. Of the 361 supplements on file for warfarin, 16 carry a major rating, and the danger runs in both directions: some add to w…”

Reviewed by 2 · Jul 18, 2026

Open the Warfarin interaction page

One more smart check

Taking Yellow Dock as Part of a Dietary Supplement Product? Check It for Interactions

We hold 753 real supplement products containing Yellow Dock, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Yellow Dock. Your product may carry other ingredients that interact with Warfarin too, on top of Yellow Dock — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Yellow Dock and Warfarin 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.

Supplement Yellow Dock
Top 25%

#268 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Warfarin
Top 10

#4 of 2,830 medications looked up here in the last 7 days

29 days ago today

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.

Supplement

About Yellow Dock

What is Yellow Dock?

  • Constipation
  • Digestive support
  • Skin conditions
  • Iron-deficiency or 'blood-building' tonic
  • Liver and detox support

Yellow dock is a traditional herb used mostly as a mild laxative and a digestive and skin tonic. Good-quality human studies are lacking, so its benefits are largely unproven, and its naturally occurring oxalates and anthraquinones mean it should be used cautiously and not long-term.

Read the full Yellow Dock monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand name: Warfarin

Warfarin sodium tablets and Jantoven tablets are both used to prevent and treat venous thrombosis (blood clots in the veins) and pulmonary embolism (a clot in the lungs). They are also used to prevent clot-related complications in people with atrial fibrillation (an irregular heart rhythm) or who have had a heart valve replaced.

In people who have had a heart attack, warfarin is used to reduce the risk of death, another heart attack, stroke, or other clotting events. It does not dissolve an existing clot, but it helps prevent the clot from growing and stops new dangerous clots from forming.

See full Warfarin drug information
Keep checking

Other Drugs & Yellow Dock

Browse every other medication we’ve checked against Yellow Dock — both the ones with a known interaction and the ones without. Select any drug for the full detail.

76Major
1Moderate
0Minor
2,752No known interaction
76 Major 1 Moderate 2,752 No interaction
Major

76 interactions

Showing 60 of 76 major interactions — see all 76 on the Yellow Dock page.

Moderate

1 interaction

No interaction 2,752 drugs checked — show the list

We also checked Yellow Dock against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,752 medications checked with no known interaction — see the full Yellow Dock list.

See the full Yellow Dock interactions page
See every supplement checked against Warfarin, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

Keep exploring
Yellow Dock monograph › Uses, safety, and every drug interaction in one place Warfarin supplement interactions › Every supplement checked against Warfarin, ranked by severity Warfarin drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Yellow Dock and Warfarin Together: Common Questions

Can you take Yellow Dock with Warfarin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Yellow Dock and Warfarin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Warfarin and Yellow Dock?

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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.