Fo-ti + Warfarin
Warfarin brand name: Warfarin.
Warfarin 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 reportFo-ti and Warfarin
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 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).
CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES
1 of 7Why this applies to Warfarin
Warfarin falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Fo-ti interacts with.
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.
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 gist for warfarin. Lab and animal studies hint that fo-ti can slow down an enzyme called CYP2C19, which helps your body clear part of your warfarin dose. If that enzyme works slower, warfarin could linger and build up, nudging your blood-thinning effect higher than expected. In real terms, that might show up as easier bruising, nosebleeds, bleeding gums, or a rise in your INR.
I want to be honest though: this is only theoretical, based on test-tube and animal data, and it hasn't actually been seen in people. Still, warfarin is a drug where small shifts matter a lot. Please don't start or stop anything on your own. Loop in your pharmacist or doctor first, and they may want to check your INR more closely.
- 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
- 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
- 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
CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES
2 of 7Warfarin also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.
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.
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 deal with Fo-ti and warfarin. Warfarin is your blood thinner, and it's a tricky one because the dose has to be just right. Too much and you bleed more easily (think bruising, nosebleeds, or worse); too little and a dangerous clot can slip through. Fo-ti contains compounds that, in test-tube and animal studies, can slow down or speed up an enzyme called CYP1A2 that helps process certain medications.
The honest truth is that this hasn't been shown in real people, and the lab results actually went both ways depending on how the Fo-ti was prepared. So I'd call this a theoretical concern rather than a proven one. Still, because warfarin leaves so little room for error, please loop in your pharmacist or doctor before adding Fo-ti, especially since it may also stress the liver.
- 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
- 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
- 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
CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES
3 of 7Warfarin also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.
Animal and in vitro research suggests that fo-ti may inhibit CYP2C9. However, this interaction has not been reported in humans.
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 gist: your body relies on a liver enzyme called CYP2C9 to break down warfarin. Lab and animal studies hint that Fo-ti might slow that enzyme down. If that happens, warfarin could linger longer and hit harder, which means a higher chance of bruising, nosebleeds, or more serious bleeding.
I'll be straight with you though, this has only been seen in test tubes and animals, not in real people, so it's more of a theoretical caution than a proven problem. Still, warfarin is one of those medicines where even small shifts matter, and your INR can drift before you feel anything. Please don't start or stop Fo-ti on your own. Loop in your doctor or pharmacist first so they can watch your INR if needed.
- 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
- 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
- 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
CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES
4 of 7Warfarin also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.
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.
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 gist with warfarin and Fo-ti. Lab research hints that Fo-ti might slow down CYP3A4, one of the liver enzymes that helps clear warfarin. If that happened in your body, warfarin could build up a bit and thin your blood more than intended, which raises the risk of bruising, nosebleeds, bleeding gums, or more serious bleeding.
Now, the important part: this is only test-tube evidence, and animal studies didn't agree. It has never actually been reported in people, so I don't want to alarm you. Still, warfarin is a finicky drug where even small shifts matter, and Fo-ti has its own liver-safety concerns. Please loop in your pharmacist or doctor before combining them, and keep up your regular INR checks.
- 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
- 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
- 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
ANTICOAGULANT/ANTIPLATELET DRUGS
5 of 7Warfarin also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.
Some of these drugs include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), dipyridamole (Persantine), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.
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 concern with pairing Fo-ti and warfarin. Warfarin is a tricky drug to balance, and your liver makes the very clotting factors warfarin works against. Fo-ti has been tied to rare cases of liver injury, and a damaged liver makes fewer clotting factors. That can push your warfarin effect too far, raising your INR and your bleeding risk.
In one real case, a person stable on warfarin took Fo-ti for about 90 days, developed hepatitis, and saw their INR shoot up to nearly 15. Watch for warning signs like unusual bruising, nosebleeds, blood in urine or stool, or dark or pink urine. This is anecdotal evidence, not proven cause and effect, but please check with your pharmacist or doctor before combining them.
- 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
WARFARIN (Coumadin)
6 of 7Fo-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.
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 thing to keep in mind if you take warfarin and are thinking about Fo-ti. This is a theoretical concern based on how Fo-ti behaves in the body, not on strong studies, but it's worth knowing. Fo-ti can act like a stimulant laxative and cause diarrhea, especially the raw root, and ongoing diarrhea can push your INR up and make warfarin too strong. On top of that, Fo-ti has been tied to cases of liver injury, and a stressed liver makes fewer clotting factors, which also boosts warfarin's effect.
Warfarin is a narrow-margin drug, so even small shifts matter. A higher INR means more bruising, nosebleeds, blood in urine or stool, or harder-to-stop bleeding. Please loop in your doctor or pharmacist before combining these, and don't change your warfarin on your own.
- 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.
- McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
- 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
- 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
- McGuffin, M., Hobbs, C., Upton, R., and Goldberg, A. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC;1997.
- 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
CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES
7 of 7Warfarin also falls under CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES.
In vitro research suggests that fo-ti might inhibit CYP2C8. However, this interaction has not been reported in humans.
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. In test-tube studies, Fo-ti appears to slow down a liver enzyme called CYP2C8, which helps clear certain medications. If that same thing happened with warfarin, your body might hold onto a bit more of it, which could nudge your blood thinning higher than intended. With a higher effect, you could see more bruising, nosebleeds, bleeding gums, or blood in the urine or stool.
That said, this is theoretical and has only been seen in the lab, not in real people. But warfarin is a touchy drug where small shifts matter, and your INR is checked closely for a reason. Please don't add Fo-ti without first checking with your pharmacist or doctor, since they may want to watch your INR more carefully.
- 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.
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.
Fo-ti Also Interacts With Other Medications
Fo-ti has 1,256 moderate known drug interactions in our database — the Warfarin one above is among them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Fo-ti
We haven’t checked that one against Fo-ti yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Fo-ti. Pick one to open its full report.
Questions About Fo-ti 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 Fo-ti 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:
- Does Ginger Water Interfere With Amoxicillin-Clavulanate? ›
- Can You Take Nattokinase With a 40 mg Statin? ›
- Is Krill Oil Safe To Take With Losartan? ›
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
This page covers Fo-ti 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
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 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:
Where Fo-ti 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.
#193 of 1,452 supplements looked up here in the last 7 days
#7 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 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.
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.
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.
No drugs match “”.
1,256 interactions
- Diclofenac Sodium ›
- Diltiazem ›
- Theophylline ›
- Nifedipine ›
- Ibuprofen ›
- Aspirin ›
- Hydrocortisone ›
- Insulin (rdna) ›
- Naproxen ›
- Doxycycline ›
- Erythromycin ›
- Estradiol ›
- Minocycline ›
- Propranolol ›
- Tetracycline ›
- Lidocaine ›
- Amoxicillin ›
- Hydrochlorothiazide ›
- Norethindrone ›
- Testosterone ›
- Verapamil ›
- Fenofibrate ›
- Levonorgestrel ›
- Prednisone ›
- Quinidine ›
- Cyclosporine ›
- Dexamethasone ›
- Glyburide ›
- Insulin (pork) ›
- Methyltestosterone ›
- Triazolam ›
- Zopiclone ›
- Bupropion ›
- Ciprofloxacin ›
- Colchicine ›
- Fentanyl ›
- Flurbiprofen ›
- Isotretinoin ›
- Orphenadrine ›
- Oxybutynin ›
- Oxycodone ›
- Phenytoin ›
- Prednisolone ›
- Tacrolimus ›
- Temazepam ›
- Allopurinol ›
- Budesonide ›
- Carbamazepine ›
- Clindamycin ›
- Dextromethorphan ›
- Diclofenac Potassium ›
- Dipyridamole ›
- Doxorubicin ›
- Fluticasone ›
- Formoterol ›
- Indomethacin ›
- Insulin (human) ›
- Miconazole ›
- Morphine Sulfate ›
- Trimipramine ›
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
We also checked Fo-ti against these medications and found no known interaction in our sources. Open any page to confirm.
- Levothyroxine ›
- Methylphenidate ›
- Ivermectin ›
- Escitalopram ›
- Docusate ›
- Hydroxyurea ›
- Valacyclovir ›
- Sumatriptan ›
- Lisinopril ›
- Acyclovir ›
- Azithromycin ›
- Lamotrigine ›
- Pregabalin ›
- Gabapentin ›
- Levothyroxine, Liothyronine ›
- Methylene Blue ›
- Candesartan Cilexetil ›
- Acetaminophen, Dextromethorphan, Doxylamine ›
- Cyclopentolate ›
- Cephalexin ›
- Roxithromycin ›
- Levetiracetam ›
- Ezetimibe ›
- Phentermine, Topiramate ›
- Dexmethylphenidate ›
- Levothyroxine Sodium ›
- Carbidopa, Levodopa ›
- Thyroid Hormone ›
- Pizotifen ›
- Daptomycin ›
- Hexobarbitone ›
- Levodopa ›
- Mitomycin ›
- Flutemetamol F-18 ›
- Pegunigalsidase Alfa-iwxj ›
- Bentoquatam ›
- Cefaclor ›
- Alglucosidase Alpha ›
- Hethylphenidate Hcl ›
- Salbutamol Sulfate ›
- Amobarbital, Ephedrine Sulfate ›
- Factor 7a ›
- Azelaic Acid ›
- Minoxidil ›
- Atenolol ›
- Ribavirin Aerosol ›
- Tocainide ›
- Hydroxychloroquine ›
- Phenylephrine ›
- Rocuronium ›
- Vancomycin ›
- Lorazepam ›
- Procainamide ›
- Triptorelin ›
- Alginic Acid, Aluminum Hydroxide ›
- Dirithromycin ›
- Telmisartan ›
- Ferric Derisomaltose ›
- Crotalidae Polyvalent Immune Fab ›
- Benzocaine/menthol ›
Showing the 60 most looked-up of 1,573 medications checked with no known interaction — see the full Fo-ti 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 Fo-ti and Warfarin Together: Common Questions
Can you take Fo-ti with Warfarin?
Why are there 7 interactions listed for Fo-ti and Warfarin?
How serious is the Fo-ti and Warfarin interaction?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Still Have a Question About Warfarin and Fo-ti?
Our pharmacists answer your medication & supplement questions — free.
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.