Drug & supplement interaction

Forsythia + dabigatran

dabigatran brand names: Pradaxa, Pradax.

Moderate Interaction
The bottom line Moderate

Forsythia has a moderate interaction with dabigatran. Theoretically, taking forsythia with anticoagulant or antiplatelet drugs might increase the risk of bleeding due to decreased platelet aggregation.

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

Forsythia and dabigatran

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to dabigatran

dabigatran falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Forsythia interacts with.

Theoretically, taking forsythia with anticoagulant or antiplatelet drugs might increase the risk of bleeding due to decreased platelet aggregation. Forsythia might reduce platelet aggregation by inhibiting platelet activating factor. Some of these drugs include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.
Severity Moderate Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the deal with combining forsythia and dabigatran (Pradaxa). Dabigatran is already a powerful blood thinner that works by directly blocking thrombin, a key step in clotting. Forsythia, on the other hand, may slightly reduce how well your platelets stick together. These are two different ways of affecting clotting, so stacking them could, in theory, nudge your bleeding risk a little higher.

I want to keep this in perspective, though. This concern comes only from lab and animal studies, not real human cases, and it's rated as unlikely. Still, with a drug like dabigatran, even small shifts matter, so watch for things like easy bruising, nosebleeds, bleeding gums, or unusually dark stools. Please check with your pharmacist or doctor before adding forsythia rather than deciding on your own.

References
  1. Iwakami S, Wu JB, Ebizuka Y, Sankawa U. Platelet activating factor (PAF) antagonists contained in medicinal plants: lignans and sesquiterpenes. Chem Pharm Bull (Tokyo) 1992;40:1196-8. 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

Forsythia Also Interacts With Other Medications

Forsythia has 121 moderate, 1 minor known drug interactions in our database — the dabigatran 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 Forsythia

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

From our Q&A

Questions About Forsythia or dabigatran

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Forsythia or dabigatran, 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:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With dabigatran

This page covers Forsythia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the dabigatran page lists 235 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Danshen (major), Piracetam (major), St. John's Wort (major) and Aconite (moderate).

By severity: 4 major · 201 moderate · 30 minor.

From our pharmacist’s overview on the dabigatran page

“Dabigatran (Pradaxa) is a blood thinner prescribed to prevent strokes and dangerous clots, which makes the stakes for mixing in supplements higher than for most medicines, and I would go through this list with real care. Of the 235 ingredients on file, 202 could add to dabigatran's blood-thinning effect and increase bruising or bleedin…”

Reviewed by 2 · Jul 18, 2026

Open the dabigatran interaction page

One more smart check

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

We hold 355 real supplement products containing Forsythia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Forsythia. Your product may carry other ingredients that interact with dabigatran too, on top of Forsythia — 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 Forsythia and dabigatran 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 Forsythia
Top 25%

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

29 days ago today
Medication dabigatran
Top 10%

#167 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 Forsythia

What is Forsythia?

  • Colds and flu symptoms
  • Sore throat
  • Fever
  • Inflammation
  • Antimicrobial support

Forsythia is a traditional Chinese herb, used mainly for cold and flu symptoms and as part of multi-herb formulas. Most evidence comes from laboratory, animal, and traditional use rather than strong human studies, so its real-world benefits remain unproven. Talk to your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or taking other medicines.

Read the full Forsythia monograph & all interactions
Medication

About Dabigatran

What Is Dabigatran Used For?

Brand names: Pradaxa, Pradax

Dabigatran etexilate capsules are approved for adults to reduce the risk of stroke and systemic embolism (blood clots traveling through the body) in non-valvular atrial fibrillation (an irregular heart rhythm not caused by a heart valve problem). Capsules are also used to treat deep vein thrombosis (DVT — a blood clot in a deep vein, usually the leg) and pulmonary embolism (PE — a clot in the lungs), to prevent those clots from coming back, and to prevent DVT and PE in adults who have had hip replacement surgery.

For children, the capsule form is approved for treating VTE (venous thromboembolism — blood clots in veins) and reducing recurrence in patients aged 8 to under 18. Pradaxa Oral Pellets are approved specifically for children aged 3 months to under 12 years for the same treatment and recurrence-prevention purposes.

See full Dabigatran drug information
Keep checking

Other Drugs & Forsythia

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

0Major
121Moderate
1Minor
2,707No known interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Forsythia page.

Minor

1 interaction

No interaction 2,707 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 Forsythia and dabigatran Together: Common Questions

Can you take Forsythia with dabigatran?
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 Forsythia and dabigatran 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 dabigatran and Forsythia?

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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.