Chanca Piedra

What is Chanca Piedra?

Chanca piedra is Phyllanthus niruri L., and the one placebo-controlled trial in calcium stone formers randomized 69 patients, in 2004, and found no difference in stone passage or pain relief between the herb and placebo. That trial, Nishiura and colleagues in Urological Research 32(5):362, is the single most important document in the entire commercial story of this plant, and almost nobody selling it mentions the result.

The plant itself is a small annual of the Phyllanthaceae, formerly placed in the Euphorbiaceae, described by Linnaeus in Species Plantarum in 1753. It reaches roughly 50 to 70 cm, carries ascending herbaceous branches, and hangs its tiny capsules in a row along the underside of each leafy branchlet, which is why the English trade names run to “seed-under-leaf” and “gale of the wind.” It grows across the humid tropics from the Amazon basin through Central America into India and Southeast Asia, often as a disturbed-ground weed rather than a cultivated crop.

Common Names

• Chanca piedra, from Quechua chanca, to crush or pound, joined to Spanish piedra, stone. The literal sense is stone breaker or stone shatterer.
• Quebra-pedra and arranca-pedras in Brazilian Portuguese, both meaning break-stone or pull-out-stone.
• Stonebreaker, stone breaker, seed-under-leaf, gale of the wind in English commerce.
• Bhumyamalaki or bhumi amla in Ayurvedic usage, keezhanelli in Tamil.
• Zhen zhu cao and ye xia zhu in Chinese materia medica, though those names properly belong to P. urinaria; dukung anak in Malay.

Primary Active Compounds

• Lignans, principally phyllanthin and hypophyllanthin, with niranthin, nirtetralin and phyltetralin alongside them. Phyllanthin is the conventional marker compound for extract standardization.
• Ellagitannins, chiefly geraniin and corilagin. Geraniin was characterized as an angiotensin-converting enzyme inhibitor isolated from P. niruri by Ueno and colleagues in the Journal of Natural Products 51(2):357 in 1988.
• Flavonoids including quercetin and rutin derivatives, plus phenolic acids, sterols and alkaloids. A 2026 review in Current Pharmaceutical Design counted 120 reported phytoconstituents across the species.

Key Note

Four Phyllanthus species circulate under the same common names, and they are not chemically interchangeable. P. niruri L., P. amarus Schumach. & Thonn., P. urinaria L. and P. debilis Klein ex Willd. have been confused in commerce, in the older literature, and in the herbarium record for decades. Nearly all of the stone-specific human and animal work was done on P. niruri, while most of the hepatitis B work was done on P. amarus. Reading across from one to the other is a mistake, and the supplement aisle makes that mistake constantly.

This is a botanical with a real mechanistic signal in crystallization chemistry, a name that overpromises, and a clinical file thinner than its shelf presence suggests.

Primary Functions & Benefits

The functions that survive scrutiny are narrow and mostly biochemical rather than clinical.

Modifying calcium oxalate crystal behavior. Barros, Schor and Boim, in Urological Research 30(6):374, applied an aqueous extract at 0.25 mg/mL to urine from 14 Wistar rats and 18 human donors. The extract did not prevent calcium oxalate from precipitating. What it did was produce crystals that were significantly smaller than controls and inhibit their aggregation when read at 24 hours. The target is crystal architecture, not crystal formation.

Reducing urinary calcium in hypercalciuric patients. In the Nishiura 2004 randomized trial, the whole cohort showed no significant change in urinary parameters. In the hypercalciuric subset, mean urinary calcium fell from 4.8 ± 1.0 to 3.4 ± 1.1 mg/kg/24 h, P < 0.05. That is a real finding in a subgroup, not a whole-population effect.

Shifting other urinary risk factors. Pucci and colleagues, International Brazilian Journal of Urology, 2018, gave 56 patients with stones under 10 mm a P. niruri infusion, two 4.5 g sachets daily or 9 g of herb per day, for 12 weeks followed by a 12-week washout. Urinary potassium rose from 47.3 ± 16.7 at baseline to 56.2 ± 21.8 mg per 24 h, P = 0.017, and the magnesium to creatinine ratio rose from 58 ± 22.5 to 69.1 ± 28.6 mg/g, P = 0.013, but both changes were significant only at the 12-week washout, not at the end of treatment. In the hyperoxaluric subgroup, urinary oxalate fell from 59.0 ± 11.7 to 28.8 ± 16.0 mg/24 h, P = 0.0002.

Adjunct use after lithotripsy. Micali and colleagues, Journal of Urology 176(3):1020, followed 150 patients after shock wave lithotripsy. Overall stone-free rate at 180 days was 93.5% with the extract versus 83.3% without, p = 0.48, which is not significant. For the 56 patients with lower calyceal stones, the rates were 93.7% versus 70.8%, p = 0.01.

Hepatoprotection, antiviral activity, glucose lowering and blood pressure lowering all appear in the literature, but the supporting human work is either tiny, uncontrolled, or conducted on a different species.

Forms & Standardization

The gap between forms is larger here than for almost any botanical on the shelf, because phyllanthin is fat-soluble and the traditional preparation is water.

Meselhy and colleagues, Molecules 25(5):1179 in 2020, ran the same P. niruri aerial parts through eight extraction routes and measured phyllanthin by HPLC. Boiling water gave the highest crude yield, 18.10 g% w/w, and the lowest phyllanthin content, 0.33 ± 0.10 mg/g of extract. Methanol gave 3.6 g% w/w at 3.1 mg/g. Soxhlet extraction with hexane gave only 0.82 g% w/w of extract but 36.2 ± 2.6 mg/g of phyllanthin. Enzyme-assisted extraction with cellulase at 9 U/g and protease at 4 U/g reached 25.9 mg/g phyllanthin and 85.87 mg/g total lignans.

That is a spread of roughly 110-fold in phyllanthin content between the cheapest water extract and the hexane Soxhlet extract of the identical plant material.

Forms in actual US commerce. Of 251 labels in the NIH Dietary Supplement Label Database carrying a chanca piedra ingredient entry, 98 are capsules, 85 are liquids, 44 are tablets, 23 are powders, and 1 is a tea bag.

Standardization language to look for. A meaningful specification names the species, names the plant part, names the marker, and gives a percentage or mg/g figure. “Standardized to 5% phyllanthin” is a specification. “4:1 extract” is a ratio, not a potency claim, and tells you nothing about lignan content unless the solvent is also disclosed.

Standardization language to distrust. One US label in the database declares Phyllanthus amarus leaf “standardized to Sesquiterpenes.” Sesquiterpenes are not the characteristic constituent class of this genus, and no clinical work anchors to them.

Whole herb versus extract. Every stone trial except the Romanian 2019 study used either a whole-plant infusion or a simple plant extract, not a lignan-enriched concentrate. Buying a 50:1 hexane-derived concentrate does not buy you the clinical evidence, because the evidence was generated on tea.

Food Sources

There are none. Phyllanthus niruri is not a food crop and does not appear in the diet outside of medicinal teas and decoctions in the regions where it grows. The related Phyllanthus emblica, Indian gooseberry or amla, is eaten as a fruit, but it is a different species with a different chemistry and nothing in the stone literature applies to it.

Who Should Take Chanca Piedra

The honest candidate list is short, and every entry on it assumes conventional stone care is already in place.

Recurrent calcium oxalate stone formers with documented hypercalciuria. This is the one group with a positive subgroup result, the 1.4 mg/kg/24 h reduction in urinary calcium in Nishiura 2004. Anyone in this category should already be on a 24-hour urine protocol and should be discussing thiazide therapy, which has a far deeper evidence base.

Patients with documented hyperoxaluria. The Pucci 2018 halving of urinary oxalate, 59.0 to 28.8 mg/24 h, was a subgroup finding in an uncontrolled design, but it is the largest effect size reported anywhere in this literature.

Patients scheduled for or recovering from shock wave lithotripsy on a lower pole stone. Micali 2006 is the closest thing to a clinically actionable result, and it applies to exactly 56 of the 150 patients studied.

People who want a low-risk addition to fluid intake and dietary change. Across the four stone trials totaling roughly 323 patients, no serious adverse events were reported. That is a reason it is reasonable to try, not a reason to expect a result.

Who should not bother. Anyone with a stone larger than about 5 mm expecting dissolution. In Cealan 2019, only stones at or below 3 mm reliably cleared, and 38.3% of the 60 stones tracked were completely unchanged after 3 months.

Who Should AVOID or Use Caution

Contraindications

• Pregnancy. Paula and colleagues, Journal of Ethnopharmacology volume 254, 2020, dosed pregnant rats at 150, 300 and 600 mg/kg by gavage through gestation. No teratogenic effect appeared, but the 600 mg/kg group showed altered maternal kidney weight and morphology, and treated animals showed fetal macrosomia and increased ossification sites. The authors warned against indiscriminate gestational use.
• Breastfeeding. No human safety data exist at any dose.
• Known allergy to Phyllanthus species or to any undeclared botanical in a multi-ingredient stone formula.

Use Caution

• Anyone on antihypertensive therapy. Srividya and Periwal, Indian Journal of Experimental Biology 33(11):861, treated 9 mild hypertensives with whole-plant P. amarus for 10 days and reported a significant fall in systolic blood pressure in the non-diabetic hypertensives and in the female subjects, alongside increased 24-hour urine volume and increased urinary and serum sodium.
• Anyone on insulin or an oral hypoglycemic. The same 9-subject study reported significantly reduced blood glucose.
• Anyone taking a prescription diuretic. The diuretic effect is documented in the same report and stacks.
• Anyone with chronic kidney disease, a solitary kidney, or a transplant. None of the stone trials enrolled these patients.
• Children. The 4 stone trials enrolled adults, with mean ages of 38 ± 8 years in Nishiura 2004 and 48 years in Cealan 2019.

Critical Safety Point

A stone that is obstructing is a surgical and urological emergency, not a supplement decision. Fever with flank pain, a single functioning kidney, anuria, or uncontrolled vomiting all mean the emergency department, immediately. The gravest risk this product carries is not toxicity. It is the delay purchased by a bottle whose name says the problem is being handled.

Recommended Dosages

Every figure below comes from a published protocol or from label data, not from a consensus standard, because no consensus standard exists.

Capsules, whole plant or simple extract: 450 mg three times daily, totaling 1,350 mg, is the Nishiura 2004 protocol and the only dose ever tested against placebo in stone formers. US capsule strengths in the label database cluster at 500, 200, 250, 100 and 1,000 mg.

Standardized extract, post-lithotripsy adjunct: 2 g daily for at least 3 months, the Micali 2006 regimen using the Uriston preparation.

Standardized extract in combination: 225 mg of dried leaf extract per capsule with magnesium and 2 mg of vitamin B6, the Cealan 2019 Romanian protocol, taken as 1 capsule twice daily over 3 months, with 48 patients enrolled and 40 completing.

Infusion or tea: The Pucci 2018 protocol used a P. niruri infusion of two 4.5 g sachets daily, 9 g of herb per day, over 12 weeks. Traditional Amazonian and Brazilian practice runs to 1 to 3 cups daily of an infusion or weak decoction of the whole plant.

Tinctures: Commercial 1:5 and 1:4 hydroalcoholic extracts are typically dosed at 2 to 6 mL two to three times daily. One widely sold US liquid declares 638 mg of herb equivalent per serving. No tincture has been tested for any stone endpoint.

Duration

The tested durations are 3 months in Nishiura 2004, 12 weeks in Pucci 2018, 3 months in Cealan 2019, and at least 3 months in Micali 2006. Nothing longer than 6 months has been formally studied in humans for any endpoint, and the Pucci design deliberately included a 12-week washout after treatment. Continuous use beyond 3 to 6 months is outside the evidence and, given the documented diuretic and hypotensive activity, worth reassessing rather than automating.

Timing & Administration

Divided dosing is what was tested. Nishiura 2004 used three doses per day, Cealan 2019 used 1 capsule twice daily over 3 months, and Micali 2006 used 2 g daily self-administered after lithotripsy sessions.

With or without food. No pharmacokinetic study establishes a food effect for phyllanthin in humans at supplement doses. The lignans are lipophilic, so taking a lignan-standardized extract with a meal containing fat is a reasonable inference rather than a tested instruction. Water extracts and teas have essentially no lignan content to worry about, 0.33 mg/g in the Meselhy data, so timing them around meals is not meaningful.

Fluid intake is the actual intervention. Every stone protocol in this literature ran against a background of increased fluid intake, and the diuretic activity documented by Srividya and Periwal in 1995 means the tea itself contributes volume. If chanca piedra appears to help, the volume is a plausible share of the reason.

Morning weighting. Given the hypotensive signal, anyone on blood pressure medication should avoid stacking the full daily dose into one evening serving and should separate it by at least 2 hours from antihypertensive dosing.

Timeline of Effects

Days 1 to 10. Increased urine volume is the only reliably reported short-term change, documented over 10 days in the 1995 human study. Nothing about stone burden changes on this timescale.

Weeks 4 to 12. Urinary chemistry shifts, where they occur, were measured at 3 months in Nishiura 2004; in Pucci 2018 the potassium and magnesium changes reached significance only at the 12-week washout, not at the end of the 12-week treatment. This is the window in which a repeat 24-hour urine collection would show a change in calcium or oxalate if one is going to happen.

Months 3 to 6. Stone-burden changes, where reported, were measured here. Pucci 2018 recorded mean stone number falling from 3.2 ± 2.0 to 2.0 ± 2.1 over 12 weeks. Cealan 2019 found 40% of 60 tracked stones absent at 3 months and a mean diameter reduction of 1.7 mm. Micali 2006 assessed clearance at 30, 60, 90 and 180 days.

What never has a timeline. Dissolution of a large stone. No controlled human study has shown a stone above roughly 5 mm dissolving on this herb. The Cealan cutoff for predicting stone-free status was 3 mm or smaller, with an area under the curve of 0.9.

When to stop. If a repeat 24-hour urine at 3 months shows no movement in the abnormality you were targeting, the reasonable conclusion is that it is not working for you.

Benefits of Taking Chanca Piedra

A measurable effect on urinary calcium in the right patient. A 29% reduction in mean urinary calcium in hypercalciuric stone formers, 4.8 to 3.4 mg/kg/24 h, is the kind of magnitude that matters for stone risk if it holds.

A large effect on urinary oxalate in hyperoxaluric patients. The Pucci 2018 subgroup result, 59.0 down to 28.8 mg/24 h, is a 51% reduction. The design was uncontrolled and the subgroup was small, so this needs replication before anyone treats it as established.

Better lower pole clearance after lithotripsy. A 22.9 percentage point improvement in stone-free rate, 93.7% versus 70.8% at 180 days, in the anatomic location where lithotripsy performs worst.

Favorable shifts in stone inhibitors. The magnesium to creatinine ratio rose 19% and the potassium to creatinine ratio rose 30% in Pucci 2018, measured at the 12-week washout rather than at the end of treatment. Both magnesium and potassium citrate are recognized levers in stone prevention.

A crystal-morphology effect with a plausible mechanism. Barros and colleagues, Urological Research 34(6):351, treated rats bearing bladder calculi at 5 mg per rat per day. Early treatment cut calculus number by 75% and weight by 65%, both P < 0.05. Treatment started after a stone had already formed did not stop growth, but changed the stone surface from spiculated to smooth, which the authors argued should make it more fragile and easier to pass.

Tolerability. Across Nishiura 2004, Micali 2006, Pucci 2018 and Cealan 2019, spanning roughly 323 treated and control participants, no serious adverse events were attributed to the herb. Micali reported no side effects at all at 2 g daily for 3 months.

Potential Negatives & Side Effects

Blood pressure reduction. Documented in humans, though in only 9 subjects over 10 days. For someone already on an ACE inhibitor or an angiotensin receptor blocker, an additive drop is the plausible failure mode, and geraniin’s ACE-inhibitory activity gives it a mechanism.

Hypoglycemia. The same 1995 report found significantly reduced blood glucose in the treated group, which included 4 subjects with diabetes mellitus.

Increased urination and sodium loss. The 1995 study recorded significant increases in 24-hour urine volume and in urinary and serum sodium. Over months, in an older person on a loop diuretic, electrolyte drift is the realistic concern.

Gastrointestinal upset. Pucci 2018 recorded abdominal pain in 66.1% of patients, dysuria in 19.6%, hematuria in 14.3%, and nausea and epigastric pain in 10.7% each during the 12-week infusion period; the authors did not attribute these to the herb, noting that pain is frequent in stone disease and that fragments were passing, and no patient discontinued. Loose stools and abdominal discomfort are also common to concentrated tannin-rich botanicals. Geraniin and corilagin are ellagitannins, and high tannin loads reduce iron absorption.

Allergic reaction. Rash, itching or swelling after starting any new botanical warrants stopping it.

The dominant real-world harm. It is not a side effect. It is the person with a 9 mm stone who takes a “stone breaker” for 3 months instead of seeing a urologist. Nothing in this literature supports dissolving a stone of that size.

Deficiency Symptoms

No deficiency of chanca piedra is possible, because the plant is a medicine rather than a nutrient. Nothing sets a recommended dietary allowance or an adequate intake for it, no deficiency syndrome has been described, and no biomarker of Phyllanthus status exists, because the human body has no requirement for it at all.

What chanca piedra addresses

• Elevated 24-hour urinary calcium in hypercalciuric stone formers, in one subgroup analysis.
• Elevated 24-hour urinary oxalate in hyperoxaluric stone formers, in one uncontrolled study.
• Residual fragment clearance from the lower pole after shock wave lithotripsy, in one trial.

Bottom line

The deficiency here is not nutritional. It is a deficit in urinary stone inhibitors and an excess of stone promoters, and chanca piedra is one candidate lever among several with far stronger evidence, including fluid intake, thiazides and potassium citrate.

Toxicity Symptoms

At high intake

No human toxicity threshold has been established, because no dose-ranging toxicity study has been run in humans. The highest tested human dose is 9 g of herb daily as an infusion for 12 weeks in the 56 patients of Pucci 2018, an uncontrolled design; the highest dose in a controlled setting is 2 g daily for 3 months in the 78 treated patients of Micali 2006, where no side effects were recorded. The highest studied animal dose relevant to safety is 600 mg/kg daily in pregnant rats, which produced altered maternal kidney weight and morphology.

Signs to reduce or stop

• Lightheadedness on standing, or home blood pressure readings falling below your usual range.
• Symptoms of low blood sugar in anyone on insulin or a sulfonylurea, including shakiness, sweating and confusion.
• Persistent nausea, cramping or loose stools past the first week.
• Any new muscle cramping, palpitations or unusual fatigue, which can signal electrolyte drift with a sustained diuretic effect.
• Darkening urine, yellowing of the eyes or right upper quadrant pain, which warrant stopping immediately and getting liver enzymes checked, despite the herb’s hepatoprotective reputation.

General note

The realistic toxicity concern with this plant is not the plant. It is what else is in the capsule. Identity failures in this genus are documented and common, and a capsule of misidentified material carries whatever risk that other species carries.

How Chanca Piedra Works

The mechanism that best fits the data is interference with crystal assembly rather than dissolution of existing mineral.

It does not dissolve calcium oxalate. Barros 2003 showed plainly that the aqueous extract at 0.25 mg/mL failed to prevent calcium oxalate precipitation in either rat or human urine. In the 2006 rat study, X-ray diffraction confirmed the extract did not change the crystalline composition of the calculi at all.

It changes crystal size and stops aggregation. Crystals formed with extract present were significantly smaller than controls, and aggregation measured at 24 hours was inhibited. Since a passable stone is one that never grows past a ureteral diameter, blocking aggregation is a more plausible route to clinical benefit than dissolving mineral.

It alters the organic matrix. Freitas, Schor and Boim, BJU International 89(9):829, gave rats 1.25 mg/mL/day for 42 days after seeding a calcium oxalate crystal into the bladder. Urinary glycosaminoglycan excretion fell, 5.64 ± 0.86 versus 11.78 ± 2.21 mg/g creatinine, while glycosaminoglycan content inside the calculi rose, 48.0 ± 10.4 versus 16.6 ± 9.6 g/g calculus. Citrate and magnesium excretion did not change. The stone was being built differently, not eroded.

It blocks crystal uptake by tubular cells. Campos and Schor, Nephron 81(4):393, showed the aqueous extract potently inhibited calcium oxalate crystal endocytosis by Madin-Darby canine kidney cells, an effect that persisted at pathologic crystal concentrations and produced no detectable cell toxicity.

It is a mild diuretic and hypotensive. Geraniin inhibits angiotensin-converting enzyme, per Ueno 1988, which is consistent with the blood pressure and urine volume findings in the 9-subject human study.

Taken together: smaller crystals, less aggregation, altered matrix incorporation, reduced tubular uptake, higher urine volume. That is a coherent antilithic mechanism. It is also, notably, a mechanism for preventing stones rather than for breaking them.

Synergistic Supplements

Potassium citrate. The most defensible pairing. Alkali citrate therapy is standard care for hypocitraturic calcium stone disease, and Pucci 2018 found P. niruri raised the potassium to creatinine ratio by 30% at washout without raising citrate, which suggests the two act on different points.

Magnesium. Cealan 2019 tested P. niruri with magnesium and vitamin B6 as a fixed combination in 48 enrolled patients, 40 of whom completed, so this is the only combination with a dedicated human trial. Pucci 2018 also found the magnesium to creatinine ratio rising 19% on the herb alone.

Vitamin B6, pyridoxine. Included at 2 mg per capsule in the Cealan protocol on the rationale that pyridoxine reduces endogenous oxalate production. The dose used is nutritional, not pharmacologic.

Water. Not a supplement, and by a wide margin the most effective intervention in this category. Every trial cited here ran on top of it.

What not to stack it with. Calcium supplements taken away from meals, which raise urinary calcium, and high-dose vitamin C, which converts to oxalate. Adding chanca piedra while doing either is working against yourself.

A note on proprietary stone blends. Several US products combine chanca piedra with hydrangea root, gravel root, celery seed and uva ursi. None of those combinations has been tested for a stone endpoint in humans, and each added botanical adds an identity risk and an interaction surface.

Interactions & What NOT to Take

CYP3A substrates. The strongest interaction signal in this genus. Taesotikul and colleagues, Xenobiotica 42(7):641, gave rats P. amarus extract at 800 mg/kg one hour before oral midazolam. Midazolam peak concentration rose 3.9-fold and area under the curve rose 9.6-fold, with clearance down 12%, while intravenous midazolam pharmacokinetics were unchanged, pointing to intestinal CYP3A inhibition. Repeated dosing at 200 or 800 mg/kg for 15 days instead induced hepatic CYP3A and CYP2B1/2. Agbonon and colleagues, Journal of Ethnopharmacology 128(2):390, separately found P. amarus strongly inhibited CYP3A5 and CYP3A7 in vitro.

What that means in practice. Roughly half of prescription drugs are CYP3A substrates. Statins, calcium channel blockers, many benzodiazepines, tacrolimus, cyclosporine, apixaban and rivaroxaban all run through it. A single dose that inhibits intestinal CYP3A and chronic dosing that induces hepatic CYP3A is the worst of both directions.

Antihypertensives. Additive blood pressure reduction, with an ACE-inhibition mechanism from geraniin. Separate doses and monitor at home.

Antidiabetic medication. Additive glucose lowering documented in humans, in a group that included diabetic subjects.

Diuretics, including thiazides and loops. Additive diuresis with documented sodium shifts.

Lithium. Any agent with sustained diuretic activity can alter lithium clearance. There is no Phyllanthus-specific study, so this is a caution based on drug class, not a documented interaction.

Anticoagulants and antiplatelets. Platelet aggregation inhibition has been reported for this genus, though not in a human trial. Caution with warfarin, aspirin and direct oral anticoagulants is reasonable, particularly given the CYP3A overlap with apixaban and rivaroxaban.

Iron supplements. Separate by 2 hours. Ellagitannin content is high and tannins bind non-heme iron.

Quality, Testing & Adulteration

This is where the category falls apart, and there are hard numbers.

Species substitution is documented and near-total in the one study that looked. Inglis and colleagues, Planta Medica 84(17):1300, used ITS, ITS2, matK, psbA-trnH, trnL and trnL-trnF barcodes to screen 48 Phyllanthus taxa and then tested 4 commercial Brazilian herbal teas sold as quebra-pedra. Three of the 4 were Phyllanthus tenellus, and one of those was mixed with alfalfa, Medicago sativa. The fourth was a mixture of Desmodium barbatum and P. niruri. Not one of the 4 was pure P. niruri.

The common barcode does not resolve the species. The same study found rbcL, one of the standard plant barcoding markers, could not reliably distinguish P. niruri from P. urinaria. A supplier claiming DNA verification without naming the marker has told you nothing.

Most US labels do not name a species at all. Of 251 labels in the NIH Dietary Supplement Label Database carrying a chanca piedra ingredient entry, 134 carry no species field at all, and 149, or 59%, name no species once the 15 entries reading only Phyllanthus spp. are counted as unnamed. Of those that do name one, 67 declare Phyllanthus amarus and only 33 declare Phyllanthus niruri. That inverts the evidence base: the species with the stone trials is named on 13% of labels, while the species with the hepatitis literature is named on 27%.

The disease-claim name is on the label in English. Thirty-six of those 255 label records print “Stone Breaker” in the English product name, across at least 6 brands.

The disclaimer is nearly universal. Two hundred thirty-three of 255 label records declare a structure/function claim, which triggers both the 30-day notification requirement in 21 CFR 101.93(a) and the mandatory disclaimer in 21 CFR 101.93(c).

What to require from a supplier. A binomial with the botanical authority, Phyllanthus niruri L., on the front panel. The plant part, aerial parts or whole herb. The extraction solvent, since water and hexane differ roughly 110-fold in phyllanthin. A marker assay by HPLC with a phyllanthin figure in mg/g or percent. An identity method that names the barcode region used, not just the word DNA. Heavy metal and microbial testing, since this is a wild-collected disturbed-ground plant.

Special Considerations

Pregnancy and lactation. Avoid. The rat reproductive data at 150 to 600 mg/kg showed maternal renal changes at the top dose and fetal macrosomia, and the plant has a traditional reputation as an emmenagogue.

Children and adolescents. No trial has enrolled them. Pediatric stone disease is rising and should be managed by a pediatric urologist.

Chronic kidney disease. Excluded from every trial cited here. The diuretic and electrolyte effects are not characterized in reduced glomerular filtration.

Transplant recipients. Treat this as contraindicated. Tacrolimus and cyclosporine are narrow-therapeutic-index CYP3A substrates, and the midazolam data show the direction and magnitude of the risk.

Uric acid and cystine stones. All the human work is in calcium oxalate stone formers. Micali 2006 specified calcium oxalate composition as an entry criterion. Uric acid stones respond to urinary alkalinization, and cystine stones need dedicated therapy.

Struvite and infection stones. The 2006 rat model produced struvite precipitation over the seeded crystal, and the herb did not alter the crystalline composition. Infection stones require antibiotics and surgery.

Hepatitis B, the cross-species trap. The famous result is Thyagarajan and colleagues in The Lancet in 1988, where 22 of 37 carriers, 59%, lost hepatitis B surface antigen versus 1 of 23, 4%, on placebo. That study used P. amarus, not P. niruri, and it did not replicate. Leelarasamee and colleagues reported failure in The Lancet in 1990, and Doshi and colleagues in the Indian Journal of Gastroenterology in 1994 found that none of 30 carriers cleared surface antigen on 250 to 500 mg three times daily. The Cochrane review CD009004 by Xia and colleagues pooled 5 randomized trials and 290 participants and found no effect on surface antigen clearance versus antiviral drugs, relative risk 1.00, 95% CI 0.93 to 1.08, with all trials at high risk of bias. None of this transfers to stones, and none of it justifies a liver claim on a stone product.

Research Status & Evidence Quality

Strong Evidence For

Nothing. There is no endpoint in this literature supported by more than one adequately powered, blinded, placebo-controlled human trial. The honest top tier is empty.

Moderate Evidence For

• Modification of calcium oxalate crystal size, aggregation and matrix incorporation. This is replicated across in vitro work, cell culture and two rat models from the same São Paulo group, with consistent direction.
• Reduction of 24-hour urinary calcium in hypercalciuric stone formers. One randomized, placebo-controlled subgroup result, from a trial whose whole treatment arm was 33 patients, with a clear mechanism and a plausible magnitude.
• Tolerability at up to 2 g daily for 3 months in adults, based on roughly 323 participants across four trials with no serious adverse events attributed.

Emerging / Preliminary Evidence For

• Improved stone-free rate after lithotripsy for lower pole stones, 93.7% versus 70.8%, p = 0.01, from a single-center study of 150 patients whose overall result, 93.5% versus 83.3%, was not significant at p = 0.48.
• Reduction of urinary oxalate in hyperoxaluria, one uncontrolled subgroup in 56 patients.
• Clearance of stones 3 mm or smaller in the upper and middle calyces, from an uncontrolled study of 40 completers on a three-ingredient combination.
• Blood pressure, glucose and diuretic effects, from a single 1995 study of 9 subjects over 10 days using a different species.

Research Limitations

The 2020 systematic review and meta-analysis by Dhawan and Olweny in the Canadian Journal of Urology 27(2):10162 is the definitive summary, and what it found is instructive. A comprehensive search of controlled human studies yielded exactly 2 that met inclusion criteria, pooling 89 treated patients against 92 controls. Stone size fell by a standardized mean difference of -0.39 cm, 95% CI -0.68 to -0.09, p = 0.01, and stone number by -0.38, 95% CI -0.68 to -0.09, p = 0.01. Heterogeneity was substantial, I² of 76% and 64%. The reviewers noted the pooled outcomes had been secondary endpoints in the original studies, which is a real problem, and that the total treated population was too small to estimate clinical impact.

Beyond that: no trial has used stone recurrence over years as a primary endpoint, which is the endpoint that matters. No trial has standardized the extract to a stated phyllanthin content. No dose-ranging study exists in humans. No trial has independently verified the botanical identity of its own material, despite the barcoding evidence that identity failure is the norm in this trade. And as of September 2026, a search of ClinicalTrials.gov returns 20 registered studies mentioning Phyllanthus, of which zero list urolithiasis or kidney stones as a condition. There is no pipeline.

Summary & Key Takeaways

Chanca piedra is a real antilithic candidate wearing a name it cannot support. The preclinical work is careful and internally consistent: the extract does not dissolve calcium oxalate, it makes the crystals smaller, stops them clumping, changes how the organic matrix is laid into the stone, and blocks tubular cells from taking crystals up. In animals, treating early cut calculus number by 75% and weight by 65%. Treating a stone that already existed changed its texture from spiculated to smooth but did not shrink it. That distinction is the whole story, and the label reverses it.

The human evidence is four trials, roughly 323 participants, one of them placebo-controlled, and a meta-analysis that could find only 2 studies worth pooling. The placebo-controlled trial missed on stone passage and pain and hit only in a hypercalciuric subgroup. The post-lithotripsy trial missed overall and hit only in the lower pole. These are signals worth chasing, and nobody is chasing them: there are zero registered stone trials underway.

Bottom Line

If you form calcium oxalate stones, have a 24-hour urine showing hypercalciuria or hyperoxaluria, are already on fluids and diet and whatever your urologist prescribed, and you want to add something with a plausible mechanism and a clean safety record over 3 months, 450 mg three times daily of verified Phyllanthus niruri L. is a defensible experiment. Recheck the 24-hour urine at 3 months. If nothing moved, stop. If you have a stone causing symptoms, this is not the intervention.

Key Safety Points

• Obstruction with fever is an emergency. A supplement named stone breaker has killed nobody, but the delay it buys can.
• CYP3A interaction is the serious pharmacologic risk. A 9.6-fold rise in oral midazolam exposure in rats is not a footnote, and transplant recipients should avoid this entirely.
• Blood pressure and blood glucose both fall measurably in humans. Monitor if you take drugs that do the same.
• Avoid in pregnancy and lactation.

Special Note

Check the binomial before you check the price. In the only published barcoding study of commercial stone-breaker herb, 0 of 4 products were pure Phyllanthus niruri, and in the US label database, 59% of 251 products naming chanca piedra decline to name any species at all. Twice as many labels name P. amarus, the hepatitis species, as name P. niruri, the stone species. A product that will not tell you which plant is inside cannot be the plant the trials studied, except by accident.