Ranked by evidence
Best supplements for preventing kidney stones
Kidney stone prevention starts with a doctor: having your stone analyzed decides what works, because citrate suits calcium stones and not every type. Drinking more fluid and prescription thiazides have stronger evidence than any supplement, and potassium citrate is the one supplement-adjacent option with a moderate grade. Picks are ranked by the evidence for preventing stones, and this page also flags supplements that raise your risk.
Picks are ranked by the strength of published evidence for this goal in otherwise healthy adults. A persistent symptom needs a clinician's evaluation, and no supplement on this list replaces treatment.
Evidence last reviewed: October 2026
Solid options
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Potassium Citrate | Moderate evidence | recurrent calcium stones | In a Cochrane review of 7 trials, citrate salts reduced new stone formation (RR 0.26) and stone growth, and a 2025 umbrella review rated the evidence high certainty. Trials used 30–60 mEq a day, which is prescription territory, and it is dangerous with kidney impairment or drugs that raise potassium. | View |
Situational
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Calcium Citrate | Moderate evidence | if you need a calcium supplement | Supplemental calcium can raise stone risk, but citrate is used to reduce stone formation and is generally the preferred calcium form for stone formers. Take it with meals and keep total calcium within 1,000–1,200 mg a day. | View |
Popular for this goal — but the evidence says skip
- Chanca Piedra Limited evidence
Its best trial found no overall benefit after lithotripsy (93.5% versus 83.3% stone-free, p=0.48), and no study shows it dissolves stones.
- Buffered Vitamin C (Sodium Ascorbate) Limited evidence
High-dose vitamin C in any form raises urinary oxalate, men taking 1,000 mg a day or more had roughly double the stone rate, and buffering does not change that.
- IP-6 (Inositol Hexaphosphate) Limited evidence
It inhibits crystal formation in the lab, but no supplement trial has measured stone recurrence.
- Calcium Moderate evidence
Calcium plus vitamin D raised kidney stone incidence by about 17% in WHI, especially when calcium is taken between meals, while calcium from food with meals lowers risk.
- Chaga Mushroom Limited evidence
It is very high in oxalate, with case reports of oxalate nephropathy and kidney failure, so avoid it entirely if you have had calcium oxalate stones.
- Kidney Support Formulas Limited evidence
No trial shows these blends support the kidneys, and herbal products are a documented cause of kidney injury.
Our verdict
If you have had calcium stones, ask your doctor about potassium citrate at therapeutic doses, since over-the-counter tablets supply far too little. If you need calcium, get it from food with meals or take calcium citrate with food. Skip chanca piedra and IP-6, avoid chaga, and keep vitamin C well under 1,000 mg a day.