Drug & supplement interaction

American Ginseng + Warfarin

Warfarin brand name: Warfarin.

Major Interaction
Medically reviewed by · Updated October 2026
The bottom line Major

American Ginseng has a major interaction with Warfarin. American ginseng seems to decrease the effectiveness of warfarin therapy.

Read the full interaction report
SeverityMajor
LikelihoodLikely
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

American Ginseng and Warfarin

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

Major

WARFARIN (Coumadin)

American ginseng seems to decrease the effectiveness of warfarin therapy.
Healthy patients receiving warfarin 5 mg daily, who also take American ginseng 1 gram twice daily, seem to have a significantly reduced international normalized ratio (INR).
Severity Major Likelihood Likely Evidence B

Well-controlled human studies have demonstrated the likely existence of this interaction.

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

Here's the gist: American ginseng can make your warfarin work less well. In a small but real study, healthy folks on warfarin who took 1 gram of American ginseng twice a day saw their INR drop noticeably. INR is the blood test that tells us how 'thin' your blood is, and warfarin is a tricky medicine where even small swings matter a lot.

If your INR falls too low, your blood can clot more easily again, which raises the risk of the very things warfarin is protecting you from, like a stroke or a clot in your leg or lungs. Please don't start or stop anything on your own. Just check with your pharmacist or doctor first, and if you do use ginseng, they may want to watch your INR more closely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Janetzky K, Morreale AP. Probable interaction between warfarin and ginseng. Am J Health Syst Pharm 1997;54:692-3. PubMed
  2. Yuan CS, Wei G, Dey L, et al. American ginseng reduces warfarin's effect in healthy patients: a randomized, controlled trial. Ann Intern Med 2004;141:23-7.

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

American Ginseng Also Interacts With Other Medications

American Ginseng has 1 major, 215 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 1 Moderate 215 No known interaction 2,614 (incl. Warfarin)
Taking anything else?

Check Another of Your Medications Against American Ginseng

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

From our Q&A

Questions About American Ginseng 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 American Ginseng 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 American Ginseng 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), Beer (major), Cannabis (major) and Danshen (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 American Ginseng as Part of a Dietary Supplement Product? Check It for Interactions

We hold 992 real supplement products containing American Ginseng, each one broken down to its full ingredient list — and combination products often carry several ingredients besides American Ginseng. Your product may carry other ingredients that interact with Warfarin too, on top of American Ginseng — 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 American Ginseng 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 American Ginseng
Top 25%

#199 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 American Ginseng

What is American Ginseng?

American Ginseng
  • Stress and energy support
  • Immune support and colds
  • Blood sugar management
  • Mental focus and clarity
  • General wellness (adaptogen)

American ginseng is an herbal root used as an 'adaptogen' to support energy, stress, immune function, and blood sugar. Some uses—such as reducing the chance or length of colds and modestly lowering after-meal blood sugar—have early supportive evidence, but most claims are not well proven. Talk to your pharmacist or doctor before use, especially if you have a health condition or take medications.

Read the full American Ginseng monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand name: Warfarin

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.

See full Warfarin drug information
Keep checking

Other Drugs & American Ginseng

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

1Major
215Moderate
0Minor
2,613No known interaction
1 Major 215 Moderate 2,613 No interaction
Major

1 interaction

Moderate

215 interactions

Showing 60 of 215 moderate interactions — see all 215 on the American Ginseng page.

No interaction 2,613 drugs checked — show the list

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

Showing the 60 most looked-up of 2,613 medications checked with no known interaction — see the full American Ginseng list.

See the full American Ginseng 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
American Ginseng 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 American Ginseng and Warfarin Together: Common Questions

Can you take American Ginseng with Warfarin?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the American Ginseng and Warfarin interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Warfarin and American Ginseng?

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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.