Kidney stone disease remains one of the most common and painful conditions in urology, affecting millions worldwide each year. Global data show a continued rise in incidence (more than 100 million new cases in 2021) making prevention and long-term management a priority for both clinicians and patients. Despite significant advances in minimally invasive treatment, many patients still ask a familiar question: “Is there a natural remedy that can help prevent stones or help me pass them?”

Phytotherapy (the use of plant-derived preparations) has been part of traditional medicine for centuries. Long before ureteroscopy and shock wave lithotripsy, healers relied on botanical extracts to relieve pain, promote urination, and support stone passage. Today, with renewed public interest in natural health approaches, phytotherapy has re-entered clinical discussions. But how much of this traditional practice is supported by modern evidence?

The following overview summarizes current data from clinical studies, systematic reviews, and preclinical research.

Which patients may benefit?

Not all stones respond equally to phytotherapy. Calcium stones, which make up 80-85 percent of cases, appear most amenable to plant-based interventions. Uric acid stones may also improve due to effects on urine pH and uric acid metabolism.

In contrast, struvite (infection) stones and cystine stones do not respond to phytotherapy; these require targeted medical therapy or surgery.

Risk stratification remains essential:

• Low-risk stone formers (small stones, infrequent episodes, no underlying metabolic abnormalities) may safely use phytotherapy as adjunctive therapy.
• High-risk stone formers (including those with recurrent stones, brushite stones, uric acid stones, chronic kidney disease, or a solitary kidney) require guideline-directed metabolic evaluation and pharmacologic treatment. For these patients, phytotherapy alone is insufficient.

How do these herbal agents work?

Although mechanisms differ across preparations, phytotherapy generally works by one or more of the following:

• Increasing urine volume
• Enhancing urinary citrate
• Reducing urinary calcium, oxalate, or uric acid
• Inhibiting crystal nucleation, growth, and aggregation
• Providing antioxidant and anti-inflammatory effects

These mechanisms are biologically plausible and supported by a growing body of literature, though the quality of evidence varies.

Clinical evidence: what we know so far

One recent narrative review compiles existing clinical and preclinical studies on phytotherapy in urolithiasis, highlighting promising effects on stone size, expulsion, and urinary chemistry while emphasizing that evidence remains limited and non-standardized.

Single-herb therapies

Phyllanthus niruri (“stone breaker”) is perhaps the most studied herb in nephrolithiasis. It has been shown to:

• Increase urinary magnesium, potassium, and citrate
• Reduce oxalate and uric acid in selected patients
• Facilitate passage of small stones (<3-4 mm)

Effects are more modest in larger stones.

Nigella sativa (black seed) randomized trials report:

• Up to 44 percent expulsion rates compared with 15 percent in placebo
• Significant reduction in stone size in more than half of treated patients

Phaseolus vulgaris (common bean broth) demonstrates increased urine output, reduced urinary calcium and oxalate, and measurable decreases in stone size and number.

Multi-herb combinations

Commercial combinations vary widely in quality and efficacy:

• Cystone: Mixed evidence
• Wu-Ling-San: Increases urine output short term; limited evidence for long-term prevention
• Five-herb mixtures (Tribulus, Urtica, corn silk, etc.): Improved expulsion rates and urine volume in some randomized controlled trials

Renalof: the most consistently supported option

Among commercial preparations, Renalof currently has the strongest clinical support. Multiple randomized trials show:

• Stone expulsion rates of 65-86 percent (vs. 11 percent in placebo)
• Significant reduction in stone surface and volume
• Best results for stones <10 mm

The AMMOS study demonstrated an approximately 25 percent reduction in stone volume at 3 months, suggesting clinical benefit as both a preventive and adjunctive therapy after shock wave lithotripsy or ureteroscopy.

Where phytotherapy fits (and where it doesn’t)

Phytotherapy should not replace guideline-based management. It cannot substitute for thiazides, potassium citrate, allopurinol, or infection-directed therapy. It also cannot treat large, obstructive, or complicated stones.

Where phytotherapy may be useful:

• Small, non-obstructive stones
• Supporting fragment clearance after shock wave lithotripsy or ureteroscopy
• Adjunctive prevention in low-risk stone formers
• Patients seeking evidence-based natural options

Where caution is needed: Patients with chronic kidney disease, solitary kidney, recurrent large stones, or those at risk for electrolyte abnormalities should avoid certain herbal diuretics, which may worsen renal function or dehydration.

Conclusion

Phytotherapy occupies an interesting space between traditional practice and emerging scientific evidence. Many plant-based therapies show promising effects on stone size, expulsion rates, and urinary chemistry, while others lack sufficient research or standardization. Importantly, phytotherapy is not currently part of the official recommendations of either the European Association of Urology (EAU) or the American Urological Association (AUA). These guidelines rely on high-quality randomized trials, and at present, the existing data remain insufficient for formal endorsement.

As evidence continues to evolve, phytotherapy may eventually find a clearer and more defined role in kidney stone prevention. For now, patients should discuss any herbal products with their urologist, as even “natural” therapies can carry risks or interact with standard treatments. Some preparations show real promise, but continued investigation is essential before they can be routinely recommended in clinical practice.

Martina Ambardjieva is a dedicated urologist and medical educator with extensive experience in both clinical practice and academic instruction. She earned her MD from the University “Sv. Kiril i Metódij” in Skopje and is a PhD candidate in urological oncology, with a focus on bladder carcinoma. Her scholarly work includes numerous publications in oncologic urology, urinary calculosis, and men’s health.

Dr. Ambardjieva currently serves as a urologist at the PHI University Surgical Clinic “Naum Ohridski” and completed her residency training at the University Urology Clinic in Skopje. Earlier in her career, she practiced as a general medical doctor at Sante Plus General Hospital and completed a medical internship at the University of Ljubljana.

In addition to her clinical responsibilities, Dr. Ambardjieva is a teaching assistant at the Medical Faculty in Skopje. She works additionally as a collaborator for Dr. Telx. She has held leadership positions in the European Medical Students’ Association and actively participates in international medical education and policy. She has attended numerous congresses and workshops in France, Italy, Canada, and Turkey, and serves as a delegate for the European Association of Urology (EAU), contributing to cross-border initiatives in urology. Certified in laparoscopic surgery, she continues to integrate patient care, research, and education in her professional work.