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Green Tea Extract and Warfarin: What Is Known and Not
Green tea extract and warfarin is a pairing to raise with a pharmacist. The NCCIH green tea page does not name warfarin, but it does report that extract lowered blood levels of two other medicines. We found no source on green tea vitamin K, so we give no figure. Other Payarmin ingredients also carry clotting notes.
Written by the Payarmin label deskUpdated · 4 min read
What is known01
Does green tea extract interact with warfarin?
The sources we read do not settle it, so treat it as an open question for your pharmacist.
NCCIH reports that high doses of green tea reduced blood levels of the drug nadolol, and that extract reduced blood levels of atorvastatin. It advises a talk with a provider if you take any medicine (NCCIH, Green tea). The page does not name warfarin.
You may have read that green tea holds vitamin K, which opposes warfarin. We did not find a source on that in our evidence list, so we state no vitamin K amount.
Warfarin dosing is tightly managed, so small changes matter to the people who adjust it. Keep taking prescribed medicine, and do not change a dose yourself.
In the Payarmin blend02
Which Payarmin ingredients have clotting notes?
Four blend ingredients carry a note about bleeding, clotting or other medicines.
| Ingredient (place) | Ceiling per mL | What the source says |
|---|---|---|
| Guarana (3rd) | 67 mg | May raise bleeding risk with warfarin and other blood thinners; clinical relevance unknown (MSKCC, Guarana) |
| Green tea extract (7th) | 29 mg | Lowered blood levels of two named medicines; warfarin not named (NCCIH, Green tea) |
| Coleus forskohlii (9th) | 22 mg | Forskolin may affect bleeding; relevance not determined (MSKCC, Forskolin) |
| Panax ginseng (12th) | 17 mg | May interfere with blood clotting (NCCIH, Asian ginseng) |
Each ceiling is 200 mg divided by the ingredient's place in the list. Real amounts may be far lower.
A second caution03
Is green tea extract riskier than drinking green tea?
For the liver, yes, according to NIH LiverTox.
LiverTox says drinking green tea has not been linked to liver injury, but green tea extract is a well-established cause of clinically apparent liver injury. Case-report doses ran from about 800 mg to 1.86 g of extract a day (NIH LiverTox, Green tea).
The Payarmin green tea line sits far below that by label order. But the amount is unprinted, so we compare nothing and claim no safety.
Payarmin: from $49 a bottle30 mL drops · 2, 3 or 6 bottles · free shipping on 3 or 6 · 60-day guarantee
See packsBefore you start04
What should I tell my anticoagulation clinic?
Tell them about every product, and ask before the first dose.
- Name the product, and show the full label with all 22 blend lines.
- Mention the four ingredients in the table above.
- Ask whether you need extra monitoring if you start.
The medicines guide and the green tea page go deeper, and the ingredient list shows every line.
FAQ05
Green tea and blood thinner questions
Does Payarmin contain vitamin K?
The Supplement Facts panel lists chromium and the 200 mg blend only, and no vitamin K line. We did not find a source on vitamin K in the herbs, so we cannot say. Ask your pharmacist if you take warfarin.
Is decaf green tea safer with a blood thinner?
We found no source in our list that answers this, so we will not guess. A pharmacist or anticoagulation clinic can advise on your own medicine and tea habits.
How do I know if a supplement is changing my blood thinner level?
Your clinic tracks that with blood tests, so tell them about any new product before you start. We cannot judge your numbers. Report unusual bruising or bleeding to your clinician right away.
Is the caffeine in green tea extract a concern with heart medicine?
It can be. Too much caffeine can raise heart rate and blood pressure (FDA, How much caffeine). The label prints no caffeine amount for the drops, so ask your clinician if you take heart medicine.
Who wrote this06
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by Gopayarmin, a Payarmin U.S. shop, not by the manufacturer or the distributor. We earn money when you buy through our order links.
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