Drug & supplement interaction

Boldo + Warfarin Sodium

Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.

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

Warfarin Sodium falls into 2 drug categories that Boldo can interact with; the most serious is rated moderate. Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Boldo and Warfarin Sodium

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Boldo interacts with whole categories of medication. Warfarin Sodium falls into 2 of those categories, so it can interact with Boldo in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

1 of 2

Why this applies to Warfarin Sodium

Warfarin Sodium falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Boldo interacts with.

Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.
Animal and in vitro research shows that boldine, a constituent of boldo, has antiplatelet activity. In one case report, an adult taking a combination of boldo and fenugreek with warfarin experienced an increase in international normalized ratio (INR); however, it is unclear if this effect was due to boldo, fenugreek, the combination, or another factor.
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 gist: warfarin already lowers your blood's ability to clot, and boldo may nudge things in the same direction. Lab and animal studies suggest boldine (a compound in boldo) can make platelets a little less sticky. There's also a single case report where someone on warfarin who took boldo along with fenugreek saw their INR climb (a sign the blood was thinning too much). We can't say for sure boldo was the cause, but the concern is real enough to mention.

If your warfarin effect gets pushed too far, you could notice easy bruising, nosebleeds, bleeding gums, or blood in the urine or stool. Since warfarin is so finely dosed, even small shifts matter. Please check with your pharmacist or doctor before adding boldo, and don't change your warfarin on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lambert J, Cormier J. Potential interaction between warfarin and boldo-fenugreek. Pharmacotherapy 2001;21:509-12. PubMed
  2. Teng, C. M., Hsueh, C. M., Chang, Y. L., Ko, F. N., Lee, S. S., and Liu, K. C. Antiplatelet effects of some aporphine and phenanthrene alkaloids in rabbits and man. J Pharm Pharmacol 1997;49(7):706-711. PubMed
Moderate

WARFARIN (Coumadin)

2 of 2
A combination of boldo and fenugreek was thought to be associated with an increased international normalized ratio (INR) in a female on warfarin. It is not clear if boldo, fenugreek, or the combination played a role in this interaction. Therefore, boldo may have additive effects with warfarin.
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 gist for warfarin (Coumadin): there's one case report where a woman taking warfarin saw her INR climb after using boldo together with fenugreek. INR is the blood test that tells us how 'thin' your blood is, so a higher number means warfarin may be working too strongly. That raises the risk of bleeding problems, like easy bruising, nosebleeds, bleeding gums, or blood in the urine or stool.

I'll be honest with you though, this is shaky evidence. It was a single report, and no one could tell whether boldo, the fenugreek, or both caused it. Warfarin is a touchy medication where even small shifts matter, so I wouldn't add boldo on your own. Please check with your pharmacist or doctor first, and if you do start it, they can watch your INR more closely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Lambert J, Cormier J. Potential interaction between warfarin and boldo-fenugreek. Pharmacotherapy 2001;21:509-12. PubMed

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

Boldo Also Interacts With Other Medications

Boldo has 481 moderate known drug interactions in our database — the Warfarin Sodium one above is among them. If you take anything else, check it against the full list below.

Moderate 481 No known interaction 2,349 (incl. Warfarin Sodium)
Taking anything else?

Check Another of Your Medications Against Boldo

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

From our Q&A

Questions About Boldo 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 Boldo 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:

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 Sodium

This page covers Boldo 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).

Open the Warfarin Sodium interaction page

One more smart check

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

We hold 173 real supplement products containing Boldo, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Boldo. Your product may carry other ingredients that interact with Warfarin Sodium too, on top of Boldo — 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 Boldo 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.

Supplement Boldo
Steady interest

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

29 days ago today
Medication Warfarin Sodium
Top 1%

#20 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 Boldo

What is Boldo?

Boldo
  • Indigestion and bloating
  • Mild constipation
  • Liver and gallbladder support
  • Appetite stimulation
  • Urinary complaints

Boldo is a South American shrub whose leaves are traditionally used for digestive and gallbladder complaints, but good human evidence is very limited. The leaves and oil contain ascaridole, which can be toxic to the liver, so only ascaridole-free products should be used and only for short periods. Talk to your pharmacist or doctor before trying it, and avoid it during pregnancy and breastfeeding.

Read the full Boldo monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand names: Coumadin, Panwarfin, Sofarin

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 & Boldo

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

0Major
481Moderate
0Minor
2,348No known interaction
481 Moderate 2,348 No interaction
Moderate

481 interactions

Showing 60 of 481 moderate interactions — see all 481 on the Boldo page.

No interaction 2,348 drugs checked — show the list

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

Showing the 60 most looked-up of 2,348 medications checked with no known interaction — see the full Boldo list.

See the full Boldo interactions page
See every supplement checked against Warfarin Sodium, 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
Boldo monograph › Uses, safety, and every drug interaction in one place Warfarin Sodium supplement interactions › Every supplement checked against Warfarin Sodium, 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 Boldo and Warfarin Sodium Together: Common Questions

Can you take Boldo with Warfarin Sodium?
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.
Why are there 2 interactions listed for Boldo and Warfarin Sodium?
Warfarin Sodium belongs to more than one drug category, and Boldo interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Boldo and Warfarin Sodium 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 Sodium and Boldo?

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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.