Drug & supplement interaction

Cascara Sagrada + Tolterodine

Tolterodine brand names: Detrol LA, Detrol.

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

Cascara Sagrada has a minor interaction with Tolterodine. Theoretically, cascara sagrada might decrease the effects of CYP3A4 substrates.

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

Cascara Sagrada and Tolterodine

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

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Tolterodine

Tolterodine falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Cascara Sagrada interacts with.

Theoretically, cascara sagrada might decrease the effects of CYP3A4 substrates.
In vitro research suggests that cascara sagrada can induce CYP3A4 enzymes, albeit to a much lower degree than rifampin, a known CYP3A4 inducer.
Severity Minor 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 your bladder medicine, tolterodine (Detrol). Your body partly clears it using a liver enzyme called CYP3A4. The thinking here is that cascara sagrada might gently speed that enzyme up, which could clear tolterodine a little faster and make it slightly less effective. In plain terms, you might notice your overactive bladder symptoms (urgency, frequent trips to the bathroom) creeping back if this really happened.

The good news: this is very theoretical. It comes only from lab studies, the effect was weak, and cascara only nudges the enzyme a tiny bit compared to strong inducers. For most people, occasional short-term cascara use is unlikely to matter much. Still, since cascara has its own safety concerns, check with your pharmacist or doctor before pairing the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Mazzari ALDA, Lacerda MG, Milton FA, et al. In vitro effects of European and Latin-American medicinal plants in CYP3A4 gene expression, glutathione levels, and P-glycoprotein activity. Front Pharmacol 2022;13:826395. PubMed

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

Cascara Sagrada Also Interacts With Other Medications

Cascara Sagrada has 122 moderate, 622 minor known drug interactions in our database — the Tolterodine one above is one of them. If you take anything else, check it against the full list below.

Moderate 122 Minor 622 No known interaction 2,086 (incl. Tolterodine)
Taking anything else?

Check Another of Your Medications Against Cascara Sagrada

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

Everything else you take

See Every Supplement That Interacts With Tolterodine

This page covers Cascara Sagrada only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tolterodine page lists 178 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Henbane (major), Scopolia (major) and St. John's Wort (major).

By severity: 5 major · 130 moderate · 43 minor.

From our pharmacist’s overview on the Tolterodine page

“Grapefruit juice is the first thing to know about with tolterodine (Detrol, Detrol LA), the overactive bladder medicine. It blocks the main enzyme that clears the drug, so blood levels can climb and side effects can climb with them.”

Reviewed by 2 · Jul 18, 2026

Open the Tolterodine interaction page

One more smart check

Taking Cascara Sagrada as Part of a Dietary Supplement Product? Check It for Interactions

We hold 849 real supplement products containing Cascara Sagrada, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cascara Sagrada. Your product may carry other ingredients that interact with Tolterodine too, on top of Cascara Sagrada — 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 Cascara Sagrada and Tolterodine 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 Cascara Sagrada
Top 25%

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

29 days ago today
Medication Tolterodine
Top 10%

#177 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 Cascara Sagrada

What is Cascara Sagrada?

Cascara Sagrada
  • Constipation
  • Bowel cleansing before procedures
  • Hemorrhoids
  • Traditional liver and gallbladder remedy

Cascara sagrada is a stimulant laxative made from the aged bark of a Pacific Northwest tree, used mainly for short-term relief of constipation. Because it can cause cramping, dehydration, and electrolyte problems—and was removed from over-the-counter laxative products in the U.S. due to safety concerns—it should only be used briefly, if at all, and with guidance from a pharmacist or doctor.

Read the full Cascara Sagrada monograph & all interactions
Medication

About Tolterodine

What Is Tolterodine Used For?

Brand names: Detrol LA, Detrol

Tolterodine — available as tablets (including Detrol and Tolterodine Tartrate tablets) and extended-release capsules (including Detrol LA and Tolterodine Tartrate extended-release capsules) — is prescribed for overactive bladder. It targets three main symptoms: a sudden, hard-to-control urge to urinate (urgency), urinating too often (frequency), and leaking urine when that urge hits (urge urinary incontinence).

All approved forms and brands share this same indication. No additional or separate uses are listed in the prescribing information for any individual product.

See full Tolterodine drug information
Keep checking

Other Drugs & Cascara Sagrada

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

0Major
122Moderate
622Minor
2,085No known interaction
122 Moderate 622 Minor 2,085 No interaction
Moderate

122 interactions

Showing 60 of 122 moderate interactions — see all 122 on the Cascara Sagrada page.

Minor

622 interactions

Showing 60 of 622 minor interactions — see all 622 on the Cascara Sagrada page.

No interaction 2,085 drugs checked — show the list

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

Showing the 60 most looked-up of 2,085 medications checked with no known interaction — see the full Cascara Sagrada list.

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

Can you take Cascara Sagrada with Tolterodine?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Cascara Sagrada and Tolterodine interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Tolterodine and Cascara Sagrada?

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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.