Drug & supplement interaction

Cascara Sagrada + Hydrochlorothiazide, Losartan Potassium

Hydrochlorothiazide, Losartan Potassium brand name: Hyzaar.

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

Hydrochlorothiazide, Losartan Potassium falls into 2 drug categories that Cascara Sagrada can interact with; the most serious is rated moderate. Theoretically, cascara sagrada might increase the risk of hypokalemia when taken with diuretic drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cascara Sagrada and Hydrochlorothiazide, Losartan Potassium

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Cascara Sagrada interacts with whole categories of medication. Hydrochlorothiazide, Losartan Potassium falls into 2 of those categories, so it can interact with Cascara Sagrada in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

DIURETIC DRUGS

1 of 2

Why this applies to Hydrochlorothiazide, Losartan Potassium

Hydrochlorothiazide, Losartan Potassium falls under DIURETIC DRUGS — the group Cascara Sagrada interacts with.

Theoretically, cascara sagrada might increase the risk of hypokalemia when taken with diuretic drugs.
Cascara sagrada has stimulant laxative effects, and long-term use has been associated with hypokalemia.
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 keep in mind with Hyzaar (which combines hydrochlorothiazide and losartan): the hydrochlorothiazide part is a water pill that already nudges your potassium downward. Cascara sagrada, as a stimulant laxative, can also flush out potassium when used for more than a few days. Stack the two and you could end up with low potassium, what we call hypokalemia.

Low potassium can show up as muscle cramps, weakness, fatigue, or an irregular heartbeat. Honestly, this is theoretical and based on how these work rather than firm studies, so occasional use likely won't cause trouble. But cascara isn't meant for long-term use anyway. If you're considering it, please check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Hydrochlorothiazide, Losartan Potassium also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

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 honest take on pairing cascara sagrada with Hyzaar (the losartan plus hydrochlorothiazide combo): the concern on file is theoretical and comes only from lab dish studies, not from people. Those studies hint that cascara might slightly speed up a liver enzyme called CYP3A4, which could in turn lower blood levels of certain drugs. With Hyzaar, any effect on this enzyme would be small, and your blood pressure control is unlikely to change in a meaningful way from this alone.

What I'd actually keep an eye on is something different. Cascara is a stimulant laxative that can cause dehydration and throw off your potassium and other electrolytes, and hydrochlorothiazide already lowers potassium. Using both could leave you feeling dizzy, weak, or crampy. Please check with your pharmacist or doctor before combining them.

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 121 moderate, 625 minor known drug interactions in our database — the Hydrochlorothiazide, Losartan Potassium one above is among them. If you take anything else, check it against the full list below.

Moderate 121 Minor 625 No known interaction 2,084 (incl. Hydrochlorothiazide, Losartan Potassium)
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 Hydrochlorothiazide, Losartan Potassium

This page covers Cascara Sagrada only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydrochlorothiazide, Losartan Potassium page lists 314 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Asarabacca (major) and Dolomite (major).

By severity: 12 major · 259 moderate · 43 minor.

From our pharmacist’s overview on the Hydrochlorothiazide, Losartan Potassium page

“Grapefruit is the everyday item to know first if you take hydrochlorothiazide with losartan (Hyzaar). It blocks the enzyme that clears losartan, raising drug levels, and it is one of 12 major-rated entries on a list of 314 supplements and herbs, enough serious risk to warrant genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Hydrochlorothiazide, Losartan Potassium 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 Hydrochlorothiazide, Losartan Potassium 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 Hydrochlorothiazide, Losartan Potassium 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%

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

29 days ago today
Medication Hydrochlorothiazide, Losartan Potassium
Top 10%

#210 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
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
121Moderate
625Minor
2,083No known interaction
121 Moderate 625 Minor 2,083 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Cascara Sagrada page.

Minor

625 interactions

Showing 60 of 625 minor interactions — see all 625 on the Cascara Sagrada page.

No interaction 2,083 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 2,083 medications checked with no known interaction — see the full Cascara Sagrada list.

See the full Cascara Sagrada interactions page
See every supplement checked against Hydrochlorothiazide, Losartan Potassium, 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 Hydrochlorothiazide, Losartan Potassium supplement interactions › Every supplement checked against Hydrochlorothiazide, Losartan Potassium, 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 Cascara Sagrada and Hydrochlorothiazide, Losartan Potassium Together: Common Questions

Can you take Cascara Sagrada with Hydrochlorothiazide, Losartan Potassium?
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.
Why are there 2 interactions listed for Cascara Sagrada and Hydrochlorothiazide, Losartan Potassium?
Hydrochlorothiazide, Losartan Potassium belongs to more than one drug category, and Cascara Sagrada interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Cascara Sagrada and Hydrochlorothiazide, Losartan Potassium 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

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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.