Drug & supplement interaction

Chanca Piedra + Macitentan, Tadalafil

Macitentan, Tadalafil brand name: Opsynvi.

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

Macitentan, Tadalafil falls into 2 drug categories that Chanca Piedra can interact with; the most serious is rated moderate. Theoretically, use of chanca piedra might increase the levels and clinical effects of CYP3A4 substrates.

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

Chanca Piedra and Macitentan, Tadalafil

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

Why Are There 2 Interactions?

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Macitentan, Tadalafil

Macitentan, Tadalafil 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

Opsynvi combines two medicines, macitentan and tadalafil, and both are cleared from your body largely by a liver enzyme called CYP3A4. Lab studies (in test tubes, not people) suggest chanca piedra may slow that enzyme down. If that happened in the body, these drugs could build up a bit, which might mean lower blood pressure than intended. You could feel that as dizziness, lightheadedness, headache, flushing, or a stuffy nose.

The key thing to know is that this is theoretical only, based on lab work, and has not been seen in real patients. Still, because blood pressure medicines matter, I'd run any chanca piedra product by your pharmacist or doctor first before combining them.

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
Minor

ANTIHYPERTENSIVE DRUGS

2 of 2

Macitentan, Tadalafil also falls under ANTIHYPERTENSIVE DRUGS.

Theoretically, concomitant use of chanca piedra with antihypertensive drugs might have additive blood pressure lowering effects.
Animal research suggests that chanca piedra can decrease blood pressure. However, this effect was not observed in most hypertensive patients treated with chanca piedra for 10 days.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Opsynvi combines two blood pressure lowering medicines: macitentan (an endothelin receptor blocker) and tadalafil (the same drug found in Cialis). Both are used for pulmonary arterial hypertension, and both naturally tend to relax blood vessels and nudge your blood pressure down. The idea here is simple addition. If chanca piedra also lowers blood pressure a little, stacking it on top of Opsynvi could, in theory, drop your numbers a bit more than expected.

The good news is that this concern is mostly theoretical. It comes from animal studies, and in one small human study people taking chanca piedra for 10 days didn't really see lower blood pressure. Still, if you notice dizziness, lightheadedness, or feeling faint when you stand up, mention it to your pharmacist or doctor before making any changes.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Srividya N, Periwal S. Diuretic, hypotensive and hypoglycaemic effect of Phyllanthus amarus. Indian J Exp Biol 1995; 33:861-4.
  2. Amaechina, F. C. and Omogbai, E. K. Hypotensive effect of aqueous extract of the leaves of Phyllanthus amarus Schum and Thonn (Euphorbiaceae). Acta Pol.Pharm. 2007;64(6):547-552.

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 870 moderate, 149 minor known drug interactions in our database — the Macitentan, Tadalafil one above is among them. If you take anything else, check it against the full list below.

Moderate 870 Minor 149 No known interaction 1,811 (incl. Macitentan, Tadalafil)
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 Macitentan, Tadalafil

This page covers Chanca Piedra only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Macitentan, Tadalafil page lists 264 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), Beer (major) and Grapefruit (major).

By severity: 10 major · 215 moderate · 39 minor.

From our pharmacist’s overview on the Macitentan, Tadalafil page

“Opsynvi pairs macitentan and tadalafil to lower pressure in the lung arteries, so anything that drops blood pressure further or shifts how the body handles these drugs deserves genuine respect, and I would read this list carefully. Ten of the 264 ingredients rate major, and most of the rest fall into two camps: additive blood-pressure-…”

Reviewed by 2 · Jul 18, 2026

Open the Macitentan, Tadalafil 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 Macitentan, Tadalafil 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 Macitentan, Tadalafil 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%

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

29 days ago today
Medication Macitentan, Tadalafil
Top 25%

#464 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
870Moderate
149Minor
1,810No known interaction
870 Moderate 149 Minor 1,810 No interaction
Moderate

870 interactions

Showing 60 of 870 moderate interactions — see all 870 on the Chanca Piedra page.

Minor

149 interactions

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

No interaction 1,810 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 1,810 medications checked with no known interaction — see the full Chanca Piedra list.

See the full Chanca Piedra interactions page
See every supplement checked against Macitentan, Tadalafil, 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 Macitentan, Tadalafil supplement interactions › Every supplement checked against Macitentan, Tadalafil, 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 Macitentan, Tadalafil Together: Common Questions

Can you take Chanca Piedra with Macitentan, Tadalafil?
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 Chanca Piedra and Macitentan, Tadalafil?
Macitentan, Tadalafil belongs to more than one drug category, and Chanca Piedra 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 Chanca Piedra and Macitentan, Tadalafil 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.