Drug & supplement interaction

Star Of Bethlehem + Phenolphthalein

Phenolphthalein brand names: Modane, Evac-Q-Tab, Modane Mild.

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

Star Of Bethlehem has a moderate interaction with Phenolphthalein. Theoretically, excessive use of stimulant laxatives with star of Bethlehem might increase the risk of toxicity.

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

Star Of Bethlehem and Phenolphthalein

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

Moderate

STIMULANT LAXATIVES

Why this applies to Phenolphthalein

Phenolphthalein falls under STIMULANT LAXATIVES — the group Star Of Bethlehem interacts with.

Theoretically, excessive use of stimulant laxatives with star of Bethlehem might increase the risk of toxicity.
Star of Bethlehem contains cardiac glycosides. Excessive use of stimulant laxatives can cause diarrhea, resulting in potassium depletion. This might increase the risk of cardiac glycoside toxicity.
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 thing to know about pairing Star of Bethlehem with phenolphthalein (an old stimulant laxative once sold as Modane). The plant naturally contains cardiac glycosides, the same kind of heart-active chemicals found in plants like foxglove. Stimulant laxatives can cause watery diarrhea, and when that happens you lose potassium. Low potassium makes the body more sensitive to those glycosides, which in theory could raise the risk of heart rhythm problems, nausea, or weakness.

I want to be honest: this is a theoretical concern based on how these substances work, not on real cases. Most flower-essence products are so diluted they contain almost no plant chemical. Still, if you're using a laxative often and taking any Star of Bethlehem product, check in with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Waud RA. The action of Ornithogalum umbellatum on the heart. J Pharmacol Exp Ther 1954;111:147-51. DOI
  2. 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 Phenolphthalein 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. Phenolphthalein)
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.

Everything else you take

See Every Supplement That Interacts With Phenolphthalein

This page covers Star Of Bethlehem only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenolphthalein page lists 46 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Jalap (major), Oleander (major), Alder Buckthorn (moderate) and Aloe (moderate).

By severity: 3 major · 34 moderate · 9 minor.

From our pharmacist’s overview on the Phenolphthalein page

“Phenolphthalein is a stimulant laxative itself, and that is the heart of the problem with these combinations. Most of the herbs on file, jalap being one, act the same way, so pairing them can drain fluid and potassium quickly.”

Reviewed by 2 · Jul 18, 2026

Open the Phenolphthalein 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 Phenolphthalein 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 Phenolphthalein 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
Steady interest

#1,129 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phenolphthalein
Top half

#1,224 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
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 Phenolphthalein, 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 Phenolphthalein supplement interactions › Every supplement checked against Phenolphthalein, ranked by severity 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 Phenolphthalein Together: Common Questions

Can you take Star Of Bethlehem with Phenolphthalein?
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 Phenolphthalein 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 Phenolphthalein and Star Of Bethlehem?

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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.