Drug & supplement interaction

Mullein + Diclofenac Sodium

Diclofenac Sodium brand names: Voltaren XR, Voltaren, Voltaren SR, Diclo, Difenac, and others.

Minor Interaction
The bottom line Minor

Mullein has a minor interaction with Diclofenac Sodium. Lab tests on extracts from different parts of common and dense-flowered mullein plants show that they do have some blood-thinning effects, as they increase the time it takes for blood to clot.

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceA
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Interaction report

Mullein and Diclofenac Sodium

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

Minor

Anticoagulant/Antiplatelet Drugs

Why this applies to Diclofenac Sodium

Diclofenac Sodium falls under Anticoagulant/Antiplatelet Drugs — the group Mullein interacts with.

Lab tests on extracts from different parts of common and dense-flowered mullein plants show that they do have some blood-thinning effects, as they increase the time it takes for blood to clot. This is likely due to at least one of the known constituents of muellein, triterpenoid saponins. However, the effects appear to be mild and results have been inconsistent. Extracts from different plant parts have been show to have varying anticoagulant strengths, with water-based ones being more potent than alcohol-based extracts.
Severity Minor Likelihood Unlikely Evidence A

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 gist with mullein and your diclofenac. Diclofenac itself is an NSAID that can already irritate the stomach lining and make bleeding a little more likely, especially with longer use. Mullein, in lab studies, has shown some mild blood-thinning activity, probably from plant compounds called triterpenoid saponins. So in theory, the two together could nudge your bleeding risk up a touch.

That said, I wouldn't lose sleep over it. The evidence here is from test-tube studies, not people, and the results were weak and inconsistent. A cup of mullein tea for a cough is unlikely to matter. If you take diclofenac daily or notice easy bruising, dark stools, or stomach upset, check in with your pharmacist or doctor first.

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

Mullein Also Interacts With Other Medications

Mullein has 121 minor known drug interactions in our database — the Diclofenac Sodium 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 Mullein

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

From our Q&A

Questions About Mullein or Diclofenac Sodium

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

This page covers Mullein only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diclofenac Sodium page lists 308 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Piracetam (major).

By severity: 7 major · 266 moderate · 35 minor.

From our pharmacist’s overview on the Diclofenac Sodium page

“Diclofenac (Voltaren), a daily mainstay for arthritis and joint pain, comes with a supplement list that calls for real vigilance. Of the 308 ingredients on file, 7 rate major, and roughly two hundred entries share a single theme: anything with blood-thinning activity adds to diclofenac's own bleeding risk, especially in the stomach.”

Reviewed by 2 · Jul 18, 2026

Open the Diclofenac Sodium interaction page

One more smart check

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

We hold 780 real supplement products containing Mullein, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Mullein. Your product may carry other ingredients that interact with Diclofenac Sodium too, on top of Mullein — 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 Mullein and Diclofenac Sodium 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 Mullein
Top 25%

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

29 days ago today
Medication Diclofenac Sodium
Top 25%

#398 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 Mullein

What is Mullein?

Mullein
  • Cough and chest congestion
  • Sore throat
  • Bronchitis and respiratory irritation
  • Earache (traditional ear oil)
  • Mild inflammation

Mullein is a traditional herbal remedy most often used as a tea or syrup to soothe coughs, sore throats, and respiratory irritation. High-quality human studies are lacking, so its benefits are not well proven, but it is generally considered low-risk for short-term use in healthy adults. Talk to your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or have a medical condition.

Read the full Mullein monograph & all interactions
Medication

About Diclofenac

What Is Diclofenac Used For?

Brand names: Voltaren XR, Voltaren, Voltaren SR, Diclo, Difenac, Diclo SR, Voltarol, Acoflam, Defenac, Dicloflex, Diclovol, Diclozip, Fenactol, Flamrase, Volraman, Diclomax SR, Diclomax Retard, Motifene 75 mg, Voltarol 75 mg SR, Acoflam 75 SR, Defenac SR, Dexomon 75 SR, Dicloflex 75 SR, Diclovol SR, Fenactol 75 mg SR, Flamatak 75 MR, Flamrase SR, Flexotard MR 75, Rheumatac Retard 75, Rhumalgan CR, Slofenac SR, Volsaid Retard 75, Voltarol Retard, Acoflam Retard, Defenac Retard, Dexomon Retard 100, Dicloflex Retard, Diclovol Retard, Fenactol Retard 100 mg, Flamatak 100 MR, Volsaid Retard 100, Voltarol Ophtha Multidose, Voltarol Ophtha, Pennsaid, Voltaren Emulgel, Dyloject

Diclofenac comes in many forms, and each one is approved for different uses. Which one you get depends on what you are treating.

  • Oral tablets: osteoarthritis, rheumatoid arthritis, and (delayed-release) ankylosing spondylitis, plus period pain and mild to moderate pain for the immediate-release potassium tablets.
  • Capsules: mild to moderate acute pain in adults.
  • Oral solution (powder for solution): acute treatment of migraine attacks in adults.
  • Topical gel and solution: osteoarthritis pain, mainly of the knees (and hands for the gel).
  • Skin patches (Flector, diclofenac epolamine): acute pain from minor strains, sprains and bruises.
See full Diclofenac drug information
Keep checking

Other Drugs & Mullein

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

0Major
0Moderate
121Minor
2,708No known interaction
Minor

121 interactions

Showing 60 of 121 minor interactions — see all 121 on the Mullein page.

No interaction 2,708 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

Keep exploring
Pharmacist Counseling Corner

Taking Mullein and Diclofenac Sodium Together: Common Questions

Can you take Mullein with Diclofenac Sodium?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Mullein and Diclofenac Sodium interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Diclofenac Sodium and Mullein?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.