Drug & supplement interaction

Thyme + Fondaparinux

Fondaparinux brand name: Arixtra.

Moderate Interaction
The bottom line Moderate

Thyme has a moderate interaction with Fondaparinux. Theoretically, thyme leaf extract might have additive effects with anticoagulant or antiplatelet drugs.

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

Thyme and Fondaparinux

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Fondaparinux

Fondaparinux falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Thyme interacts with.

Theoretically, thyme leaf extract might have additive effects with anticoagulant or antiplatelet drugs.
In vitro and animal research suggests that thyme leaf extract has antiplatelet effects. However, this effect has not been observed 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: fondaparinux (Arixtra) is already a powerful blood thinner, given as a shot to prevent or treat clots. Thyme, in lab and animal studies, seems to make platelets a little less sticky. Stack that on top of fondaparinux and, in theory, your blood could thin slightly more than intended, which might mean easier bruising, nosebleeds, or bleeding that takes longer to stop.

I want to be honest about the evidence though: this antiplatelet effect from thyme has not actually been seen in people, and the cooking amounts you sprinkle on food are very unlikely to matter. Concentrated thyme supplements or extracts are the bigger question mark. Since fondaparinux is serious medicine, just give your pharmacist or doctor a heads-up before adding any thyme product.

References
  1. Okazaki K, Kawazoe K, Takaishi Y. Human platelet aggregation inhibitors from thyme (Thymus vulgaris L.). Phytother Res 2002;16:398-9. .
  2. Yamamoto J, Yamada K, Naemura A, et al. Testing various herbs for antithrombotic effect. Nutrition 2005;21(5):580-7. PubMed
  3. Tognolini, M., Barocelli, E., Ballabeni, V., Bruni, R., Bianchi, A., Chiavarini, M., and Impicciatore, M. Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. Life Sci. 2-23-2006;78(13):1419-1432. 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

Thyme Also Interacts With Other Medications

Thyme has 378 moderate known drug interactions in our database — the Fondaparinux one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Thyme

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

Everything else you take

See Every Supplement That Interacts With Fondaparinux

This page covers Thyme only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fondaparinux page lists 202 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Danshen (major), Piracetam (major), Aconite (moderate), Allspice (moderate) and Aloe (moderate).

By severity: 2 major · 183 moderate · 17 minor.

From our pharmacist’s overview on the Fondaparinux page

“Most people on fondaparinux (Arixtra) are recovering from surgery or treating a blood clot, exactly the moment supplements for circulation and recovery come out of the cabinet. This pairing deserves real care, because nearly all 202 ingredients on this list share one problem: they thin the blood a little on their own, so adding them to…”

Reviewed by 2 · Jul 18, 2026

Open the Fondaparinux interaction page

One more smart check

Taking Thyme as Part of a Dietary Supplement Product? Check It for Interactions

We hold 708 real supplement products containing Thyme, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Thyme. Your product may carry other ingredients that interact with Fondaparinux too, on top of Thyme — 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 Thyme and Fondaparinux 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 Thyme
Top 25%

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

29 days ago today
Medication Fondaparinux
Top 10%

#239 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 Thyme

What is Thyme?

Thyme
  • Cough and respiratory congestion
  • Sore throat
  • Digestive upset
  • Antimicrobial and antiseptic uses
  • Flavoring in cooking

Thyme is a common kitchen herb that has long been used for coughs, sore throats, and digestive complaints. It is generally safe in the amounts found in food, and some cough products that combine thyme with other herbs have modest supporting evidence, but high-quality research on thyme alone is limited. The concentrated essential oil should never be swallowed undiluted.

Read the full Thyme monograph & all interactions
Medication

About Fondaparinux Injection

What Is Fondaparinux Injection Used For?

Brand name: Arixtra

Fondaparinux sodium injection is used to prevent deep vein thrombosis (DVT) — blood clots that form in the legs — in adults who are having hip fracture surgery, hip replacement surgery, knee replacement surgery, or abdominal surgery. Preventing these clots also lowers the risk of a clot traveling to the lungs (pulmonary embolism, or PE).

It is also used to treat acute DVT and acute pulmonary embolism in adults, typically started alongside warfarin. In children aged 1 year and older who weigh at least 10 kg (about 22 lbs), fondaparinux sodium injection is approved to treat venous thromboembolism (VTE) — blood clots in the veins.

See full Fondaparinux Injection drug information
Keep checking

Other Drugs & Thyme

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

0Major
378Moderate
0Minor
2,451No known interaction
Moderate

378 interactions

Showing 60 of 378 moderate interactions — see all 378 on the Thyme page.

No interaction 2,451 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

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Pharmacist Counseling Corner

Taking Thyme and Fondaparinux Together: Common Questions

Can you take Thyme with Fondaparinux?
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.
How serious is the Thyme and Fondaparinux 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 Fondaparinux and Thyme?

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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.