Drug & supplement interaction

Chanca Piedra + Letrozole, Ribociclib Succinate

Letrozole, Ribociclib Succinate brand name: Kisqali Femara Co-Pack.

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

Chanca Piedra has a moderate interaction with Letrozole, Ribociclib Succinate. Theoretically, use of chanca piedra might increase the levels and clinical effects of CYP3A4 substrates.

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

Chanca Piedra and Letrozole, Ribociclib Succinate

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Letrozole, Ribociclib Succinate

Letrozole, Ribociclib Succinate falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Chanca Piedra interacts with.

Theoretically, use of chanca piedra might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that chanca piedra extract inhibits CYP3A4. Theoretically, chanca piedra might increase the levels of CYP3A4 substrates. This interaction has not been reported in humans.
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

Your Kisqali Femara combo (ribociclib plus letrozole) is handled in the body partly by a liver enzyme called CYP3A4. Lab studies suggest chanca piedra can slow that enzyme down. In theory, that could let these medicines build up a bit higher than expected. With ribociclib especially, higher levels can mean more nausea, fatigue, low blood counts, or effects on your heart rhythm (QT prolongation), which is something your oncology team already watches closely.

I want to be honest that this is theoretical, seen only in test-tube research and never reported in actual patients. Still, because this is serious cancer therapy with careful dosing, I'd skip the supplement unless your oncologist or pharmacist okays it first. Please don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Husain I, Abdulrahman B, Dale OR, et al. Interaction of Phyllanthus amarus extract and its lignans with human xenobiotic receptors, drug metabolizing enzymes and drug transporters. J Ethnopharmacol 2025;339:119142. 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

Chanca Piedra Also Interacts With Other Medications

Chanca Piedra has 872 moderate, 149 minor known drug interactions in our database — the Letrozole, Ribociclib Succinate one above is one of them. If you take anything else, check it against the full list below.

Moderate 872 Minor 149 No known interaction 1,809 (incl. Letrozole, Ribociclib Succinate)
Taking anything else?

Check Another of Your Medications Against Chanca Piedra

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

Everything else you take

See Every Supplement That Interacts With Letrozole, Ribociclib Succinate

This page covers Chanca Piedra only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Letrozole, Ribociclib Succinate page lists 155 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), Cesium (major) and Ephedra (major).

By severity: 8 major · 109 moderate · 38 minor.

From our pharmacist’s overview on the Letrozole, Ribociclib Succinate page

“Grapefruit tops my worry list for anyone taking the Kisqali Femara Co-Pack (letrozole and ribociclib), because it blocks the enzyme, CYP3A4, that clears ribociclib and can push levels of this breast cancer drug higher than intended. That enzyme thread runs through 121 of the 155 ingredients on this page, and with eight rated major, rea…”

Reviewed by 2 · Jul 18, 2026

Open the Letrozole, Ribociclib Succinate interaction page

One more smart check

Taking Chanca Piedra as Part of a Dietary Supplement Product? Check It for Interactions

We hold 355 real supplement products containing Chanca Piedra, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chanca Piedra. Your product may carry other ingredients that interact with Letrozole, Ribociclib Succinate too, on top of Chanca Piedra — 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 Chanca Piedra and Letrozole, Ribociclib Succinate 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 Chanca Piedra
Top 25%

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

29 days ago today
Medication Letrozole, Ribociclib Succinate
Top half

#945 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 Chanca Piedra

What is Chanca Piedra?

Chanca Piedra
  • Kidney stones
  • Gallstones
  • Liver support
  • Urinary tract health
  • Digestive complaints

Chanca piedra is a tropical herb traditionally used as a 'stone breaker' for kidney and gallstones, and for liver and urinary health. Human evidence for these uses is limited and mostly small or preliminary, so it should not replace proven treatments. Talk with your pharmacist or doctor before using it, especially if you have a medical condition or take medications.

Read the full Chanca Piedra monograph & all interactions
Keep checking

Other Drugs & Chanca Piedra

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

0Major
872Moderate
149Minor
1,808No known interaction
872 Moderate 149 Minor 1,808 No interaction
Moderate

872 interactions

Showing 60 of 872 moderate interactions — see all 872 on the Chanca Piedra page.

Minor

149 interactions

Showing 60 of 149 minor interactions — see all 149 on the Chanca Piedra page.

No interaction 1,808 drugs checked — show the list

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

Showing the 60 most looked-up of 1,808 medications checked with no known interaction — see the full Chanca Piedra list.

See the full Chanca Piedra interactions page
See every supplement checked against Letrozole, Ribociclib Succinate, 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
Chanca Piedra monograph › Uses, safety, and every drug interaction in one place Letrozole, Ribociclib Succinate supplement interactions › Every supplement checked against Letrozole, Ribociclib Succinate, 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 Chanca Piedra and Letrozole, Ribociclib Succinate Together: Common Questions

Can you take Chanca Piedra with Letrozole, Ribociclib Succinate?
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 Chanca Piedra and Letrozole, Ribociclib Succinate 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 Letrozole, Ribociclib Succinate and Chanca Piedra?

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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.