Drug & supplement interaction

Alder Buckthorn + Phenolphthalein

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

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

Alder Buckthorn has a moderate interaction with Phenolphthalein. Alder buckthorn has stimulant laxative effects.

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

Alder Buckthorn 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 Alder Buckthorn interacts with.

Alder buckthorn has stimulant laxative effects. Concomitant use with stimulant laxative medications might compound fluid and electrolyte loss.
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 simple version: both alder buckthorn and phenolphthalein are stimulant laxatives. They work in similar ways, prodding your colon to squeeze harder and pulling extra water into the bowel. So taking them together is a bit like doubling up on the same job. The worry isn't a chemical clash, it's that the effects stack on top of each other.

When that happens, you can lose too much fluid and important minerals like potassium, leaving you with watery diarrhea, cramping, dehydration, weakness, or even an irregular heartbeat in heavier cases. This concern is theoretical, based on how these products behave rather than firm studies, so don't panic. Still, I'd skip the combo and check with your pharmacist or doctor before using either one.

Contact Dr. Brian directly if you have additional questions on this interaction
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

Alder Buckthorn Also Interacts With Other Medications

Alder Buckthorn has 121 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 121 No known interaction 2,709 (incl. Phenolphthalein)
Taking anything else?

Check Another of Your Medications Against Alder Buckthorn

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

Everything else you take

See Every Supplement That Interacts With Phenolphthalein

This page covers Alder Buckthorn 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), Aloe (moderate) and Black Hellebore (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 Alder Buckthorn as Part of a Dietary Supplement Product? Check It for Interactions

We hold 19 real supplement products containing Alder Buckthorn, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Alder Buckthorn. Your product may carry other ingredients that interact with Phenolphthalein too, on top of Alder Buckthorn — 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 Alder Buckthorn 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 Alder Buckthorn
Top half

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

29 days ago today
Medication Phenolphthalein
Top half

#1,093 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 Alder Buckthorn

What is Alder Buckthorn?

Alder Buckthorn
  • Constipation
  • Bowel cleansing before procedures
  • Occasional irregularity

Alder buckthorn bark is a stimulant laxative traditionally used for short-term relief of constipation. It can work, but it carries real risks with prolonged use, including bowel damage, and should only be used briefly, if at all, after checking with a pharmacist or doctor.

Read the full Alder Buckthorn monograph & all interactions
Keep checking

Other Drugs & Alder Buckthorn

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

0Major
121Moderate
0Minor
2,708No known interaction
121 Moderate 2,708 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Alder Buckthorn page.

No interaction 2,708 drugs checked — show the list

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

Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Alder Buckthorn list.

See the full Alder Buckthorn 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
Alder Buckthorn 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 Alder Buckthorn and Phenolphthalein Together: Common Questions

Can you take Alder Buckthorn 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 Alder Buckthorn 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 Alder Buckthorn?

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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.