Drug & supplement interaction

Hedge Mustard + Erythromycin

Erythromycin brand names: Erythro S, PCE, E-Mycin, Erythro-ES, EryPed Chewable, and others.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Hedge Mustard has a moderate interaction with Erythromycin. Theoretically, taking hedge mustard with macrolide antibiotics might increase the risk of cardiac glycoside toxicity.

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

Hedge Mustard and Erythromycin

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

Moderate

MACROLIDE ANTIBIOTICS

Why this applies to Erythromycin

Erythromycin falls under MACROLIDE ANTIBIOTICS — the group Hedge Mustard interacts with.

Theoretically, taking hedge mustard with macrolide antibiotics might increase the risk of cardiac glycoside toxicity.

The flowering above ground parts of hedge mustard contain cardioactive glycosides. Macrolide antibiotics appear to increase the gastrointestinal absorption of oral digoxin. Theoretically, concomitant use of macrolide antibiotics might increase the absorption of the cardiac glycosides found in hedge mustard.
Severity Moderate Likelihood Possible Evidence D

Interaction 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.

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

Here's the twist with this pairing: it's not really erythromycin that builds up, it's the heart-active compounds (cardiac glycosides) naturally found in hedge mustard's flowering parts. Erythromycin can boost how much of these glycoside-type substances your gut absorbs, the same way it's known to raise digoxin levels. So in theory, taking hedge mustard alongside erythromycin could nudge those heart compounds higher in your system.

If that happened, you might notice an irregular or pounding heartbeat, nausea, or dizziness. I'll be honest though, this is a theoretical concern based on how these things work, not proven cases. Still, since it touches the heart, it's worth a quick chat with your pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 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

Hedge Mustard Also Interacts With Other Medications

Hedge Mustard has 132 moderate known drug interactions in our database — the Erythromycin one above is one of them. If you take anything else, check it against the full list below.

Moderate 132 No known interaction 2,698 (incl. Erythromycin)
Taking anything else?

Check Another of Your Medications Against Hedge Mustard

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

From our Q&A

Questions About Hedge Mustard or Erythromycin

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

This page covers Hedge Mustard only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Erythromycin page lists 204 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 153 moderate · 40 minor.

From our pharmacist’s overview on the Erythromycin page

“Erythromycin calls for more supplement caution than most antibiotics, and the reason is one liver enzyme, CYP3A4. Erythromycin both blocks that enzyme and is broken down by it, so grapefruit can push erythromycin levels up while St.”

Reviewed by 2 · Jul 18, 2026

Open the Erythromycin interaction page

How much people look this up

Where Hedge Mustard and Erythromycin 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 Hedge Mustard
Steady interest

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

29 days ago today
Medication Erythromycin
Top 25%

#375 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 Hedge Mustard

What is Hedge Mustard?

  • Hoarseness and voice loss
  • Sore throat
  • Cough
  • Mild laryngitis
  • Throat irritation

Hedge mustard is a traditional European herb long nicknamed the 'singer's plant' because it was used to soothe hoarseness and sore throats. Solid scientific evidence for these uses is very limited, so it is best seen as a folk remedy rather than a proven treatment. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Hedge Mustard monograph & all interactions
Medication

About Erythromycin

What Is Erythromycin Used For?

Brand names: Erythro S, PCE, E-Mycin, Erythro-ES, EryPed Chewable, Eryc, Ery-Tab, Rythro Enca, Erythro E-C, Erythro Base, Ilosone, Ilotycin

Erythromycin treats bacterial infections caused by susceptible organisms. Oral and intravenous forms are used for upper and lower respiratory tract infections, skin and soft-tissue infections, pertussis (whooping cough), Legionnaires' disease, sexually transmitted infections (gonorrhea, syphilis, chlamydia), listeriosis, and other conditions. Erythrocin Lactobionate IV and erythromycin lactobionate injection are specifically for patients who cannot take oral medication or who need rapid, high blood levels due to severe infection — IV therapy should be switched to oral as soon as appropriate.

Erythromycin topical solution 2% and Ery 2% Pads (swabs) are indicated only for the topical treatment of acne vulgaris (acne) and are applied directly to the skin — they are not used for internal infections.

See full Erythromycin drug information
Keep checking

Other Drugs & Hedge Mustard

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

0Major
132Moderate
0Minor
2,697No known interaction
132 Moderate 2,697 No interaction
Moderate

132 interactions

Showing 60 of 132 moderate interactions — see all 132 on the Hedge Mustard page.

No interaction 2,697 drugs checked — show the list

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

Showing the 60 most looked-up of 2,697 medications checked with no known interaction — see the full Hedge Mustard list.

See the full Hedge Mustard interactions page
See every supplement checked against Erythromycin, 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
Hedge Mustard monograph › Uses, safety, and every drug interaction in one place Erythromycin supplement interactions › Every supplement checked against Erythromycin, ranked by severity Erythromycin 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 Hedge Mustard and Erythromycin Together: Common Questions

Can you take Hedge Mustard with Erythromycin?
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 Hedge Mustard and Erythromycin 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 Erythromycin and Hedge Mustard?

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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.