Quick answer

Ask your pharmacist or doctor before combining. The warfarin label names echinacea among botanicals that can interact with warfarin through CYP450 liver enzymes, and MedlinePlus lists it among herbal products that may interact. The label asks for more frequent INR checks whenever a botanical is started or stopped.^1,2

Key facts

The warfarin label says drugs that speed up the enzymes CYP2C9, 1A2 or 3A4 can lower warfarin's effect, and drugs that slow them can raise it.¹
In healthy volunteers, echinacea sped up CYP3A and slowed the clearance of caffeine, which CYP1A2 handles.^3,4
In 12 healthy men, echinacea slightly lowered levels of S-warfarin after a single dose, without a significant change in INR.⁵
NCCIH says the evidence on echinacea and medicines broken down by the liver is conflicting.⁶

Ask your pharmacist or doctor first

The warfarin label names echinacea among botanicals that can interact with warfarin through CYP450 liver enzymes, and asks for more frequent INR checks whenever a botanical is started or stopped. MedlinePlus also lists echinacea among herbal products that may interact with warfarin.^1,2

On the medicine's label

What is documented

Two official sources name echinacea for warfarin. The warfarin label lists it with grapefruit juice, ginkgo, goldenseal and St. John's wort as botanicals and foods that can interact with warfarin through CYP450 enzymes. MedlinePlus lists it among nonprescription and herbal products that may interact with warfarin, and asks you to tell your doctor and pharmacist before you start.^1,2

Neither source says which way the effect goes for echinacea. The label explains that something which speeds up these enzymes can lower warfarin's effect, and something that slows them can raise it. Either change can move your INR, the blood test your doctor uses to set your warfarin dose.^1,2

How it is known

On the label: the warfarin label names echinacea, and asks for more frequent INR checks when any botanical is started or stopped¹
Reported in studies: in healthy volunteers, echinacea sped up CYP3A, one of the enzymes that clear warfarin, and slowed CYP1A2, another^1,3,4
With warfarin itself, one small study found a slight drop in S-warfarin levels but no significant change in INR⁵

In 12 healthy men, two weeks of echinacea before a single dose of warfarin slightly lowered blood levels of S-warfarin, its more active form, with no significant change in INR, platelet clumping or clotting.⁵

That study gave a single dose of warfarin to 12 healthy men. It cannot show what happens in someone who takes warfarin every day, and it does not change what the label asks for.^1,5

Which blood thinners this covers

The official sources name warfarin only. The apixaban label asks you to avoid medicines that strongly speed up both P-gp and CYP3A4, naming St. John's wort, but it does not name echinacea, and neither does the MedlinePlus apixaban page.^7,8

We also read the labels for rivaroxaban, dabigatran, clopidogrel and ticagrelor and found no mention of echinacea. That is not a finding either way, so ask your pharmacist about your own medicine.

Signs of bleeding to report

Whatever else you take, MedlinePlus asks people on warfarin to call their doctor straight away about signs of bleeding, including these.²

Nosebleeds, bleeding gums, or bleeding that won't stop²
Easy bruising²
Pink, red or dark brown urine, or red or tarry black bowel movements²
Coughing or throwing up blood, or material that looks like coffee grounds²
Heavier menstrual flow, headache, dizziness or weakness²

What to ask your pharmacist

Could echinacea change my INR, and should it be checked more often when I start or stop it?
Does my blood thinner depend on the liver enzymes that echinacea affects?
Do any of my other products, such as a multivitamin, contain echinacea?
Is there another reason for me to avoid echinacea, such as an immune condition or a medicine that suppresses the immune system?

Bring the Supplement Facts panel of everything you take. Echinacea also turns up inside multi-ingredient blends, where the label may not give its amount.

Questions people ask

Can I take echinacea with apixaban?

The apixaban label and its MedlinePlus page do not name echinacea, and we found no study of the two together. That is not evidence either way, so ask your pharmacist.^7,8

Does the form or amount of echinacea matter?

The sources name echinacea in general, not a species, plant part or dose, and products vary widely. The warfarin label asks for INR checks whenever any botanical is started or stopped, whatever its form.^1,9

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.