Drug & supplement interaction

Fo-ti + Warfarin Sodium

Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.

Moderate Interaction
The bottom line Moderate

Warfarin Sodium falls into 7 drug categories that Fo-ti can interact with; the most serious is rated moderate. Theoretically, fo-ti may increase the levels and clinical effects of drugs metabolized by CYP2C19.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions7
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Fo-ti and Warfarin Sodium

These two interact in 7 distinct ways. Each one is explained separately below.

Why Are There 7 Interactions?

Fo-ti interacts with whole categories of medication. Warfarin Sodium falls into 7 of those categories, so it can interact with Fo-ti in 7 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

1 of 7

Why this applies to Warfarin Sodium

Warfarin Sodium falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Fo-ti interacts with.

Theoretically, fo-ti may increase the levels and clinical effects of drugs metabolized by CYP2C19.
Animal and in vitro research suggests that fo-ti may inhibit CYP2C19. An in vitro study suggests that the degree of CYP2C19 inhibition may depend on the type of fo-ti extract (i.e., the raw plant leads to greater inhibition than extensively processed extracts). However, this interaction has not been reported in humans.
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 situation with warfarin and Fo-ti. Lab and animal studies hint that Fo-ti may slow down a liver enzyme called CYP2C19, which is one of the pathways your body uses to clear warfarin. If that enzyme is blocked, warfarin could build up a bit and thin your blood more than intended. With warfarin, even small shifts matter, since too much can mean easy bruising, nosebleeds, or more serious bleeding.

I'll be honest: this interaction is theoretical and hasn't actually been reported in people, so it's not a sure thing. Still, because warfarin is so finicky and Fo-ti can also stress the liver, please loop in your pharmacist or doctor before adding it, and keep your INR checks on schedule.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 7

Warfarin Sodium also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, fo-ti might increase or decrease the levels and clinical effects of drugs metabolized by CYP1A2.
In vitro research suggests that fo-ti might inhibit CYP1A2. Additionally, in vitro research suggests that the degree of CYP1A2 inhibition depends on the type of fo-ti extract (i.e., the raw plant leads to greater inhibition than extensively processed extracts). However, in an animal study, an aqueous extract of fo-ti inhibited CYP1A2 while an alcoholic extract of fo-ti induced CYP1A2. Induction or inhibition of CYP1A2 by fo-ti has not been reported in humans.
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 situation with Fo-ti and warfarin. Warfarin is a true blood thinner (not a prodrug), and your body clears part of it through a liver enzyme called CYP1A2. In lab and animal studies, Fo-ti has been shown to either slow down or speed up that enzyme depending on the preparation. If it slows the enzyme, warfarin could build up and thin your blood too much, raising your risk of bruising, nosebleeds, or more serious bleeding. If it speeds the enzyme, warfarin could become less effective and let a clot form.

The big caveat: this has only been seen in test tubes and animals, never confirmed in people. Still, warfarin is a narrow-margin drug where small shifts matter, so please check with your doctor or pharmacist before adding Fo-ti, and keep up with your INR testing.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed
Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

3 of 7

Warfarin Sodium also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.

Theoretically, fo-ti may increase the levels and clinical effects of drugs metabolized by CYP2C9.
Animal and in vitro research suggests that fo-ti may inhibit CYP2C9. However, this interaction has not been reported in humans.
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 with warfarin: your liver uses an enzyme called CYP2C9 to break it down and clear it out. Lab and animal studies hint that Fo-ti may slow that enzyme down. If that happened in your body, warfarin could build up and thin your blood more than intended, raising the risk of bruising, nosebleeds, bleeding gums, or more serious bleeding.

I want to be honest about the evidence though. This effect has only been seen in test tubes and animals, never confirmed in people, so it's more of a theoretical caution than a proven problem. Still, warfarin is one of those drugs where even small shifts matter, and your INR is checked for a reason. Please don't start or stop Fo-ti without telling your doctor or pharmacist first, especially since Fo-ti has also been linked to liver injury.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

4 of 7

Warfarin Sodium also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, fo-ti might increase the levels and clinical effects of drugs metabolized by CYP3A4.
In vitro research suggests that fo-ti might inhibit CYP3A4. One in vitro study suggests that the degree of CYP3A4 inhibition may depend on the type of fo-ti extract (i.e., the raw plant leads to greater inhibition than extensively processed extracts). However, this evidence conflicts with animal research suggesting that fo-ti does not inhibit CYP3A4. This interaction has not been reported in humans.
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 with warfarin and Fo-ti. Lab studies hint that Fo-ti might slow down CYP3A4, one of the liver enzymes that helps clear warfarin. If that happens, warfarin could build up a little and thin your blood more than intended, which raises the chance of bruising, nosebleeds, or harder-to-stop bleeding. Warfarin is a narrow window drug, so even small shifts can matter.

That said, this is mostly test-tube evidence, and animal studies didn't agree. It has never actually been reported in people. I'd still be cautious, partly because Fo-ti has its own liver concerns. Please loop in your pharmacist or doctor before combining them, and keep up with your INR checks.

References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Zhang Y, Ding T, Diao T, Deng M, Chen S. Effects of Polygonum multiflorum on the activity of cytochrome P450 isoforms in rats. Pharmazie 2015;70(1):47-54. DOI
  3. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. PubMed
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

5 of 7

Warfarin Sodium also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Fo-ti has been linked to cases of acute liver failure which can decrease clotting factor production and increase the effects of anticoagulants. In one case, a patient who had been stable on warfarin presented with acute hepatitis and an INR elevated to 14.98. The patient had been taking fo-ti for 90 days prior to admission. Discontinuation of warfarin and fo-ti lead to a decrease in the INR and full recovery. Theoretically, concomitant use of fo-ti with anticoagulant or antiplatelet drugs may increase the risk of bleeding in some patients. Until more is known, monitor patients taking fo-ti and drugs that affect bleeding.
Some of these drugs include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), dipyridamole (Persantine), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.
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 concern with pairing Fo-ti and warfarin. Your liver makes the very clotting factors that warfarin works to lower. Fo-ti has been tied to a handful of liver injury reports, and if your liver gets stressed, it may produce fewer clotting factors. That can stack on top of warfarin's effect and push your blood toward being too thin.

In one published case, a person stable on warfarin took Fo-ti for about 90 days and ended up with hepatitis and an INR near 15 (far above the usual 2 to 3 target). That means a real bleeding risk: easy bruising, nosebleeds, bleeding gums, or worse. This is anecdotal, not proven, but warfarin leaves little margin for error. Please loop in your pharmacist or doctor before combining them.

References
  1. Jung KA, Min HJ, Yoo SS, et al. Drug-Induced Liver Injury: Twenty Five Cases of Acute Hepatitis Following Ingestion of Polygonum multiflorum Thunb. Gut Liver 2011;5(4):493-9. PubMed
Moderate

WARFARIN (Coumadin)

6 of 7
Theoretically, fo-ti might increase the effects and adverse effects of warfarin.
Fo-ti may have stimulant laxative effects and cause diarrhea, especially when the raw or unprocessed fo-ti root is used. Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding. Also, fo-ti has been linked to cases of acute liver failure which can decrease clotting factor production and increase the effects of warfarin. In one case, a patient who had been stable on warfarin presented with acute hepatitis and an INR elevated to 14.98. The patient had been taking fo-ti for 90 days prior to admission. Discontinuation of warfarin and fo-ti lead to a decrease in the INR and full recovery.
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 concern with pairing Fo-ti and warfarin. Warfarin is a true blood thinner with a very narrow safety window, so even small shifts can tip you toward bleeding. Fo-ti could nudge things in that direction in two ways. The raw root can act like a laxative and cause diarrhea, and ongoing diarrhea tends to push your INR up. On top of that, Fo-ti has been linked to liver injury, and since your liver makes the clotting factors warfarin already lowers, a struggling liver can amplify warfarin's effect dramatically.

This is mostly theoretical pharmacology plus one striking case (a stable patient whose INR shot up to nearly 15 after months on Fo-ti). Watch for unusual bruising, nosebleeds, or dark stools, and please check with your pharmacist or doctor before combining them.

References
  1. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Laird AR, Ramchandani N, deGoma EM, et al. Acute hepatitis associated with the use of an herbal supplement (Polygonum multiflorum) mimicking iron-overload syndrome. J Clin Gastroenterol 2008;42:861-2. PubMed
  4. Jung KA, Min HJ, Yoo SS, et al. Drug-Induced Liver Injury: Twenty Five Cases of Acute Hepatitis Following Ingestion of Polygonum multiflorum Thunb. Gut Liver 2011;5(4):493-9. PubMed
  5. McGuffin, M., Hobbs, C., Upton, R., and Goldberg, A. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC;1997.
  6. Yu J, Xie J, Mao XJ, et al. Comparison of laxative and antioxidant activities of raw, processed and fermented Polygoni multiflori radix. Chin J Nat Med 2012;10(1):63-7. DOI
Moderate

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES

7 of 7

Warfarin Sodium also falls under CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES.

Theoretically, fo-ti might increase the levels and clinical effects of drugs metabolized by CYP2C8.
In vitro research suggests that fo-ti might inhibit CYP2C8. However, this interaction has not been reported in humans.
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 short version: in lab tests, Fo-ti seems to slow down a liver enzyme called CYP2C8, which is one of the pathways that helps clear warfarin. In theory, that could let warfarin build up a little, nudging your blood toward being too thin. With a drug like warfarin, even small shifts matter, because the gap between the right dose and too much is narrow. Signs of too much would be easy bruising, nosebleeds, bleeding gums, or blood in your urine or stool.

That said, this is only seen in test-tube research and has not been reported in real people, so don't panic. Still, please loop in your pharmacist or doctor before adding Fo-ti, and keep up with your INR checks.

References
  1. Xing Y, Yu Q, Zhou L, et al. Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays. Phytomedicine 2023;112:154710. 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

Fo-ti Also Interacts With Other Medications

Fo-ti has 1,256 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.

Taking anything else?

Check Another of Your Medications Against Fo-ti

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

From our Q&A

Questions About Fo-ti 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 Fo-ti 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 Fo-ti 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 Fo-ti as Part of a Dietary Supplement Product? Check It for Interactions

We hold 976 real supplement products containing Fo-ti, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Fo-ti. Your product may carry other ingredients that interact with Warfarin Sodium too, on top of Fo-ti — 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 Fo-ti 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 Fo-ti
Top 25%

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

29 days ago today
Medication Warfarin Sodium
Top 1%

#18 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 Fo-ti

What is Fo-ti?

  • Anti-aging and longevity
  • Hair graying and hair loss
  • General tonic for vitality
  • Constipation
  • High cholesterol

Fo-ti (He Shou Wu) is a root used in traditional Chinese medicine, often promoted for healthy aging and hair. High-quality human evidence for these benefits is limited, and processed Fo-ti has been linked to reports of liver injury, so caution and professional guidance are important.

Read the full Fo-ti 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 & Fo-ti

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

0Major
1,256Moderate
0Minor
1,573No known interaction
Moderate

1,256 interactions

Showing 60 of 1,256 moderate interactions — see all 1,256 on the Fo-ti page.

No interaction 1,573 drugs checked — show the list
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
Pharmacist Counseling Corner

Taking Fo-ti and Warfarin Sodium Together: Common Questions

Can you take Fo-ti 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 7 interactions listed for Fo-ti and Warfarin Sodium?
Warfarin Sodium belongs to more than one drug category, and Fo-ti 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 Fo-ti 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 Fo-ti?

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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.