Drug & supplement interaction

Star Of Bethlehem + 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

Star Of Bethlehem has a moderate interaction with Erythromycin. Theoretically, taking macrolide antibiotics with star of Bethlehem might increase the risk of cardiac glycoside toxicity.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Star Of Bethlehem 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 Star Of Bethlehem interacts with.

Theoretically, taking macrolide antibiotics with star of Bethlehem might increase the risk of cardiac glycoside toxicity.
Star of Bethlehem contains cardiac 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 star of Bethlehem and increase the risk of adverse effects.
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 gist for erythromycin: this interaction isn't about your antibiotic getting stronger or weaker. The concern goes the other way. Star of Bethlehem naturally contains small amounts of cardiac glycosides (heart-active compounds similar to digoxin). Erythromycin can nudge up how much of these glycosides your gut absorbs, which could, in theory, push you toward glycoside toxicity (think nausea, vomiting, dizziness, vision changes, or an irregular heartbeat).

I'll be honest with you though, this is a theoretical worry based on how these compounds behave, not on real-world cases. Most flower-essence products are so diluted they contain almost no plant chemicals at all. Still, since heart-active substances have little room for error, it's worth a quick chat with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  2. Waud RA. The action of Ornithogalum umbellatum on the heart. J Pharmacol Exp Ther 1954;111:147-51. DOI
  3. Vogelsang A. Ornithogalum umbellatum in the treatment of congestive heart failure: progress report. J Am Geriatr Soc 1961;9:1096-9.

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

Star Of Bethlehem Also Interacts With Other Medications

Star Of Bethlehem has 155 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 155 No known interaction 2,675 (incl. Erythromycin)
Taking anything else?

Check Another of Your Medications Against Star Of Bethlehem

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

From our Q&A

Questions About Star Of Bethlehem 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 Star Of Bethlehem 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 Star Of Bethlehem 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

One more smart check

Taking Star Of Bethlehem as Part of a Dietary Supplement Product? Check It for Interactions

We hold 15 real supplement products containing Star Of Bethlehem, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Star Of Bethlehem. Your product may carry other ingredients that interact with Erythromycin too, on top of Star Of Bethlehem — 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 Star Of Bethlehem 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 Star Of Bethlehem
Top half

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

29 days ago today
Medication Erythromycin
Top half

#917 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 Star Of Bethlehem

What is Star Of Bethlehem?

  • Emotional shock and trauma
  • Grief and bereavement
  • Stress relief
  • Calming and comfort

Star of Bethlehem is a small flowering plant best known as one of the ingredients in Bach flower remedies, where it is used for emotional shock and grief. There is no solid scientific evidence that it treats any medical condition, and the raw plant and bulb are considered toxic, so it should not be eaten. If you choose to use a flower-essence product, treat it as a complement to—not a replacement for—proper medical care.

Read the full Star Of Bethlehem 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 & Star Of Bethlehem

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

0Major
155Moderate
0Minor
2,674No known interaction
155 Moderate 2,674 No interaction
Moderate

155 interactions

Showing 60 of 155 moderate interactions — see all 155 on the Star Of Bethlehem page.

No interaction 2,674 drugs checked — show the list

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

Showing the 60 most looked-up of 2,674 medications checked with no known interaction — see the full Star Of Bethlehem list.

See the full Star Of Bethlehem 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
Star Of Bethlehem 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 Star Of Bethlehem and Erythromycin Together: Common Questions

Can you take Star Of Bethlehem 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 Star Of Bethlehem 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 Star Of Bethlehem?

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.