Quick answer

Ask your pharmacist or doctor before combining. The warfarin label, MedlinePlus, NCCIH and NIH document 3 supplements for warfarin: ginseng, chamomile and multivitamins that contain vitamin K. MedlinePlus names 7 supplements and herbal products in all, and the label asks for more frequent INR checks whenever a botanical is started or stopped.^1,2,3,4

Key facts

MedlinePlus says warfarin is an anticoagulant used to prevent and treat blood clots, and that your response to it is checked with a regular INR blood test.²
The warfarin label lists ginseng, coenzyme Q10 and St. John's wort among botanicals that may decrease warfarin's effect.¹
MedlinePlus names coenzyme Q10, echinacea, garlic, ginkgo biloba, ginseng, goldenseal and St. John's wort as products that may interact, and says not to start any of them without talking to your health care provider.²
Warfarin works against vitamin K, so the label lists more vitamin K in the diet among factors that weaken its effect, and NIH says to talk with a provider before taking a multivitamin that contains it.^4,5
A published case reported internal bleeding in a woman taking warfarin who used chamomile tea and lotion, and a 2021 systematic review lists chamomile tea among items that may raise bleeding risk.^6,7

What is warfarin, and why do so many supplements come up?

Warfarin is a tablet taken by mouth once a day to lower the blood's ability to clot. MedlinePlus says it is used to prevent and treat blood clots, and to prevent complications in people with certain irregular heartbeats, replacement heart valves, or a past heart attack or stroke. The dose is guided by a regular blood test reported as an INR.²

Warfarin is unusual because small changes elsewhere move its effect. MedlinePlus asks you to tell your doctor and pharmacist about all vitamins, nutritional supplements and herbal or botanical products, because some of them may increase the risk of bleeding.²

Do multivitamins affect warfarin?

Warfarin acts against vitamin K, which is why MedlinePlus asks for consistent amounts of vitamin K foods from week to week and for no large amounts of leafy green vegetables or certain vegetable oils.²

Ask your pharmacist or doctor first

Vitamin K counters warfarin, and the warfarin label lists more vitamin K in the diet among the factors that weaken its effect. NIH says people who take warfarin should talk with their health care provider before taking any multivitamin that contains vitamin K.^4,5

On the medicine's label

The card is conditional. It concerns multivitamins that contain vitamin K, so the first step is reading the Supplement Facts panel for it. NIH's wording is to talk with your health care provider before taking one.^4,5

Which herbal supplements to avoid with warfarin do the label and MedlinePlus name?

Ask your pharmacist or doctor first

The warfarin label lists ginseng among the botanicals that may decrease warfarin's effect, and says the INR, the blood test that guides the dose, should be checked more often when starting or stopping botanicals. MedlinePlus also names ginseng among the herbal products that may interact with warfarin.^1,8,9

On the medicine's label

Ginseng is the botanical on this page with a full card. Echinacea and coenzyme Q10, which the label and MedlinePlus also name, sit on the blood thinners page. Garlic, ginkgo biloba and goldenseal appear on MedlinePlus's list as names only, and St. John's wort is named by both the label and MedlinePlus.^1,2

LiverTox adds one detail about ginseng: it can change how the liver handles some medicines, and a case of a weaker warfarin effect has been reported.⁹

Is chamomile tea a problem with warfarin?

Ask your pharmacist or doctor first

Interactions between chamomile and warfarin have been reported. In one published case, a woman taking warfarin was admitted to hospital with internal bleeding after using chamomile tea and lotion. The warfarin label asks for more frequent INR blood tests whenever an herbal product is started or stopped.^3,6,7,10

Reported in studies

Chamomile is the one card here tagged studies, and it deserves a careful read. The evidence is a single published case involving tea and a lotion applied to the skin, plus a 2021 systematic review of 149 reports that lists chamomile tea among items that may raise bleeding risk. The warfarin label itself does not name chamomile, but its request for more frequent INR checks covers any herbal product.^6,7,10

What does the INR check have to do with supplements?

The label and MedlinePlus both tie warfarin to blood tests. The label asks for more frequent INR monitoring whenever a botanical product is started or stopped, and MedlinePlus says to keep all appointments for the test. The practical step the sources describe is to tell the clinic before a change instead of guessing.^2,10

On the tags: the ginseng and multivitamin cards are on the label, the chamomile card is in studies, and all three are tagged ask first. None is tagged avoid, and this page does not tell anyone to start or stop a product.

What to ask your pharmacist about warfarin and supplements

Does my multivitamin, greens powder or protein powder contain vitamin K?
When should my next INR be if I start or stop an herbal product or tea?¹⁰
Which of the herbs MedlinePlus names do I already take?²
Is the medicine I was given warfarin under another name?²

For a supplement outside this page, the sources checked do not address it. That is not a finding either way, so ask your pharmacist.

Questions people ask

What supplements should not be taken with warfarin?

Official sources document ginseng, chamomile and multivitamins that contain vitamin K on this page, and echinacea and coenzyme Q10 on the blood thinners page. None is tagged avoid. The sources ask you to talk to your provider before starting or stopping any of them.^1,2,3,4

Which vitamins should I avoid with warfarin?

Vitamin K is the vitamin the label and NIH tie directly to warfarin, because warfarin works against it. The sources advise steady amounts and a conversation with your provider before taking a multivitamin that contains it. Ask your pharmacist about any other vitamin.^2,4,5

What supplements interfere with warfarin?

MedlinePlus names coenzyme Q10, echinacea, garlic, ginkgo biloba, ginseng, goldenseal and St. John's wort as products that may interact. The label lists ginseng, coenzyme Q10 and St. John's wort among botanicals that may decrease its effect.^1,2

Which dietary supplements are on the list to avoid with warfarin?

The documented ones are ginseng, chamomile and multivitamins that contain vitamin K. Chamomile rests on a case report and a review, and the others on the label. Ask your pharmacist before changing any dietary supplement.^1,4,7

Does this list apply to brand-name warfarin?

MedlinePlus lists brand names for the same medicine on its warfarin page. If your prescription label shows a brand name, ask your pharmacist to confirm that it is warfarin.²

See what we make

Every product shows its whole label and what its lab report covers. The store opens soon.

See the Full Measure line

Sources

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.