Drug & supplement interaction

Masterwort + Interferon Beta-1b

Interferon Beta-1b brand names: Betaseron, Betaferon, Extavia.

Moderate Interaction
The bottom line Moderate

Masterwort has a moderate interaction with Interferon Beta-1b. 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 Interferon Beta-1b

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

Moderate

PHOTOSENSITIZING DRUGS

Why this applies to Interferon Beta-1b

Interferon Beta-1b 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 simple version: both masterwort and Interferon Beta-1b can make your skin more sensitive to sunlight. Masterwort contains furanocoumarins, the plant chemicals known to trigger sun-related skin reactions, and interferon beta therapy can itself cause rashes and skin changes. Put them together and you may sunburn faster or develop more skin irritation than you'd expect, especially at injection sites.

Keep in mind this concern is theoretical, based on how these compounds behave rather than reports of real harm. Still, it's an easy one to manage. If you'd like to try masterwort, mention it to your pharmacist or doctor first, and in the meantime use good sun protection (sunscreen, hat, covered skin). Don't change your interferon on your own.

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 Interferon Beta-1b 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 Interferon Beta-1b

This page covers Masterwort only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Interferon Beta-1b page lists 57 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Alfalfa (moderate) and Angelica Archangelica (moderate).

By severity: 3 major · 53 moderate · 1 minor.

From our pharmacist’s overview on the Interferon Beta-1b page

“If you inject interferon beta-1b (Betaseron, Betaferon, Extavia) for multiple sclerosis, this supplement list is one to take seriously, mostly because of your liver. Interferon beta-1b can raise liver enzymes on its own, and 38 of the 57 ingredients on file add their own liver stress on top of that.”

Reviewed by 2 · Jul 18, 2026

Open the Interferon Beta-1b interaction page

How much people look this up

Where Masterwort and Interferon Beta-1b 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

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

29 days ago today
Medication Interferon Beta-1b
Top 10%

#234 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 Interferon Beta-1b Injection

What Is Interferon Beta-1b Injection Used For?

Brand names: Betaseron, Betaferon, Extavia

  • Interferon beta-1b injection is used to reduce episodes of symptoms in patients with relapsing-remitting (course of disease where symptoms flare up from time to time) of multiple sclerosis (MS, a disease in which the nerves do not function properly and patients may experience weakness, numbness, loss of muscle coordination and problems with vision, speech, and bladder control). Interferon beta-1b is in a class of medications called immunomodulators. It is not known exactly how interferon beta-1b works to treat MS.

See full Interferon Beta-1b Injection 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
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 Interferon Beta-1b Together: Common Questions

Can you take Masterwort with Interferon Beta-1b?
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 Interferon Beta-1b 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.