Drug & supplement interaction

Masterwort + Pirfenidone

Pirfenidone brand name: Esbriet.

Moderate Interaction
Medically reviewed by · Updated June 2025
The bottom line Moderate

Masterwort has a moderate interaction with Pirfenidone. The use of masterwort in conjunction with photosensitizing drugs is contraindicated due to the potential for additive photosensitizing effects.

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

Masterwort and Pirfenidone

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

Moderate

PHOTOSENSITIZING DRUGS

Why this applies to Pirfenidone

Pirfenidone falls under PHOTOSENSITIZING DRUGS — the group Masterwort interacts with.

The use of masterwort in conjunction with photosensitizing drugs is contraindicated due to the potential for additive photosensitizing effects.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

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

Here's the thing with this pair: it's not about how your body breaks down pirfenidone. Both Esbriet (pirfenidone) and masterwort can independently make your skin much more sensitive to sunlight. Pirfenidone is already well known for causing sunburn-like reactions and rashes, even with normal sun exposure. Masterwort contains furanocoumarins, the same family of compounds that do this. Put them together and the sun-sensitivity effect may simply stack on top of each other.

This concern is based on how these compounds behave (theoretical pharmacology), not on hard human studies, so I don't want to alarm you. Still, with a drug already prone to photosensitivity, it's worth being careful. Please run this by your pharmacist or doctor before combining them, and keep using sunscreen and protective clothing.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Masterwort Also Interacts With Other Medications

Masterwort has 334 moderate known drug interactions in our database — the Pirfenidone one above is one of them. If you take anything else, check it against the full list below.

Moderate 334 No known interaction 2,496 (incl. Pirfenidone)
Taking anything else?

Check Another of Your Medications Against Masterwort

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

Everything else you take

See Every Supplement That Interacts With Pirfenidone

This page covers Masterwort only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pirfenidone page lists 115 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), African Wild Potato (moderate), Alfalfa (moderate) and Angelica Archangelica (moderate).

By severity: 1 major · 80 moderate · 34 minor.

From our pharmacist’s overview on the Pirfenidone page

“Pirfenidone (Esbriet) slows the lung scarring of idiopathic pulmonary fibrosis, and when a drug is doing that kind of work, this is not a list to skim. Most of the 115 ingredients on file touch CYP1A2, the liver enzyme that clears pirfenidone, so they can push its blood level up (more nausea and liver strain) or drag it down and quietl…”

Reviewed by 2 · Jul 18, 2026

Open the Pirfenidone interaction page

How much people look this up

Where Masterwort and Pirfenidone 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 Masterwort
Top half

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

29 days ago today
Medication Pirfenidone
Top half

#760 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 Masterwort

What is Masterwort?

Masterwort
  • Digestive upset
  • Mild anxiety and tension
  • Skin complaints
  • Respiratory and cough relief
  • Traditional tonic

Masterwort (Heracleum sphondylium), a plant in the carrot family, has a long folk-medicine history for digestion, nerves, and skin. Modern scientific evidence to support these uses is very limited, and the plant can cause skin reactions to sunlight, so use it cautiously and talk with your pharmacist or doctor first.

Read the full Masterwort monograph & all interactions
Medication

About Pirfenidone

What Is Pirfenidone Used For?

Brand name: Esbriet

Pirfenidone — available as capsules and tablets under the brand name Esbriet, as well as generic pirfenidone products — is indicated for the treatment of idiopathic pulmonary fibrosis (IPF), a chronic, progressive disease in which scar tissue builds up in the lungs and makes breathing increasingly difficult.

Esbriet capsules and tablets, pirfenidone capsules, and pirfenidone tablets are each specifically approved for IPF. No other uses are supported by the available product labels.

See full Pirfenidone drug information
Keep checking

Other Drugs & Masterwort

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

0Major
334Moderate
0Minor
2,495No known interaction
334 Moderate 2,495 No interaction
Moderate

334 interactions

Showing 60 of 334 moderate interactions — see all 334 on the Masterwort page.

No interaction 2,495 drugs checked — show the list

We also checked Masterwort against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,495 medications checked with no known interaction — see the full Masterwort list.

See the full Masterwort interactions page
See every supplement checked against Pirfenidone, ranked by severity
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
Masterwort monograph › Uses, safety, and every drug interaction in one place Pirfenidone supplement interactions › Every supplement checked against Pirfenidone, ranked by severity Pirfenidone drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Masterwort and Pirfenidone Together: Common Questions

Can you take Masterwort with Pirfenidone?
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 Masterwort and Pirfenidone 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 Pirfenidone and Masterwort?

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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.