Drug & supplement interaction

Masterwort + Bendroflumethiazide, Potassium

Bendroflumethiazide, Potassium brand names: Neo-NaClex-K, Centyl K.

Moderate Interaction
The bottom line Moderate

Masterwort has a moderate interaction with Bendroflumethiazide, Potassium. 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 Bendroflumethiazide, Potassium

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

Moderate

PHOTOSENSITIZING DRUGS

Why this applies to Bendroflumethiazide, Potassium

Bendroflumethiazide, Potassium 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 gist with this pairing. Masterwort contains furanocoumarins, the same plant chemicals that can make your skin more reactive to sunlight. Bendroflumethiazide, the water pill in your Neo-NaClex-K or Centyl K, already has a known tendency to do the same thing. Put them together and the two photosensitizing effects may stack up, so you could sunburn faster or break out in a rash with less sun than usual.

This isn't about the medicine working better or worse, it's a skin-and-sun concern. And to be fair, this is based on how the chemicals behave in theory, not strong patient studies. Still, if you spend time outdoors, it's worth mentioning to your pharmacist or doctor before combining them, and lean on sunscreen and covering up.

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 Bendroflumethiazide, Potassium 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 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 Bendroflumethiazide, Potassium

This page covers Masterwort only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Bendroflumethiazide, Potassium page lists 127 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Dolomite (major), Lithium (major) and Oleander (major).

By severity: 7 major · 103 moderate · 17 minor.

From our pharmacist’s overview on the Bendroflumethiazide, Potassium page

“Bendroflumethiazide with potassium (Neo-NaClex-K, Centyl K) is a water pill for blood pressure with built-in potassium replacement, and its interaction list warrants real care rather than a quick skim. Seven of the 127 supplement ingredients on file rate major, and they concentrate on two hazards: added kidney damage (Siberian cocklebu…”

Reviewed by 2 · Jul 18, 2026

Open the Bendroflumethiazide, Potassium interaction page

How much people look this up

Where Masterwort and Bendroflumethiazide, Potassium 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 25%

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

29 days ago today
Medication Bendroflumethiazide, Potassium
Top half

#1,312 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
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
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
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 Masterwort and Bendroflumethiazide, Potassium Together: Common Questions

Can you take Masterwort with Bendroflumethiazide, Potassium?
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 Bendroflumethiazide, Potassium 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

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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.