Water is the single most important thing you can drink when trying to pass a kidney stone, but the honest answer is more nuanced than “just drink more.” Drinking enough fluid to produce roughly 2 to 2.5 liters of urine per day keeps urine dilute, which helps small stones move through the urinary tract and reduces the chance of new crystals forming. Beyond water, certain beverages like lemon juice, coffee, and some mineral waters may shift your urine chemistry in favorable ways. But there is a critical distinction most advice skips over: the majority of evidence concerns preventing stones or changing the conditions that let them grow, not physically pushing an existing stone through the ureter faster.
Stone Size Decides Whether Any Drink Can Help
Before thinking about what to drink, you need to know the size of your stone. A large study of ureteral stones found that stones 3 mm wide or smaller passed on their own about 98% of the time, while 5 mm stones passed roughly 65% of the time, and stones 6 mm or larger passed spontaneously only about a third of the time or less.1PubMed Central. Size matters: The width and location of a ureteral stone accurately predict the chance of spontaneous passage No drink will push a 7 mm stone through a 3 mm ureteral opening. If your stone is above roughly 5 to 6 mm, your urologist will likely recommend a procedure rather than watchful waiting with fluids. For smaller stones, drinking the right things genuinely matters.
Why Flooding Yourself During an Acute Attack Does Not Speed Things Up
One of the most common pieces of folk advice is to chug water during a painful kidney stone episode to “flush it out.” The evidence does not support this. A Cochrane review of studies on forced hydration during acute ureteral colic found no significant difference in pain, stone passage rates, or need for surgical removal between patients who received large volumes of intravenous fluid and those who received minimal hydration.2PubMed Central. Fluids and diuretics for acute ureteric colic A separate randomized trial confirmed the same result: forced IV hydration did not change hourly pain scores, narcotic requirements, or stone passage rates compared with minimal fluid.3PubMed. Forced versus minimal intravenous hydration in the management of acute renal colic: a randomized trial
This does not mean you should stop drinking water during a stone episode. Staying hydrated matters for overall health and prevents dehydration from nausea or vomiting, which often accompany acute pain. But aggressively forcing fluids to try to physically push the stone along can actually increase pressure in the kidney and make pain worse. Drink normally and comfortably; save the high-volume hydration strategy for the weeks and months after the stone has passed, when it genuinely helps prevent new ones.
Lemon Juice and Other Citrus Drinks
Lemon juice is probably the most widely recommended beverage for kidney stone patients besides water, and the reasoning is straightforward: lemons are rich in citrate, and citrate in urine binds to calcium, making it harder for calcium oxalate crystals to form. A systematic review and meta-analysis of citrus-based products found they raised urinary citrate levels and urine pH compared to controls, and in people who already had stones, they also lowered urinary calcium.4PubMed Central. Effect of citrus-based products on urine profile: A systematic review and meta-analysis A smaller study in patients with low urinary citrate found that lemon juice produced a 2.5-fold increase in urinary citrate, along with a decrease in urinary calcium.5PubMed. Can lemon juice be an alternative to potassium citrate in the treatment of urinary calcium stones in patients with hypocitraturia? A prospective randomized study
The picture is not perfectly clean, though. A randomized trial testing daily fresh lemon juice for preventing recurrent calcium oxalate stones found that lemon juice did not actually raise 24-hour urinary citrate excretion. The researchers proposed that extra citrate delivered to the kidneys was simply reabsorbed by the renal tubules. Instead, the benefit appeared to come through reduced sodium excretion in the urine, which lowered urine saturation by a different pathway.6PubMed Central. Fresh lemon juice supplementation for the prevention of recurrent stones in calcium oxalate nephrolithiasis: A pragmatic, prospective, randomised, open, blinded endpoint (PROBE) trial So lemon juice likely helps, but the mechanism may not be what most people assume. Practically, mixing the juice of one or two lemons into water throughout the day is a low-risk strategy that adds volume and citrate-related benefits. Avoid commercial lemonade loaded with sugar, which can raise urinary calcium excretion and partially undo the benefit.
Coffee and Tea
If you are a coffee or tea drinker, you can keep pouring. Caffeine appears to modestly reduce kidney stone risk. A large population-based study found that each step up in caffeine intake was associated with about a 5% decrease in stone risk.7PubMed Central. The association between caffeine intake and risk of kidney stones: A population-based study Three major cohorts followed over years showed that people in the highest category of caffeine intake had roughly 26 to 31% lower odds of developing a stone compared to those who consumed the least caffeine.8PubMed Central. Caffeine intake and the risk of kidney stones
The likely explanation is partly simple: coffee and tea add fluid volume. But caffeine also has a mild diuretic effect that increases urine output beyond the volume you drank, further diluting the urine. There is no strong evidence that moderate caffeine intake worsens stone risk through dehydration, a concern you sometimes see in older advice. The key is moderation. A few cups a day are fine; six espressos might contribute to dehydration if you are not drinking enough other fluids alongside them.
Cranberry Juice
Cranberry juice has a complicated reputation in the stone world. People associate it with urinary health because of its use in preventing urinary tract infections, and assume it must help with stones too. The reality is mixed. One study found that cranberry juice lowered oxalate and phosphate excretion while raising citrate, which reduced calcium oxalate supersaturation more than water alone.9PubMed. Influence of cranberry juice on the urinary risk factors for calcium oxalate kidney stone formation But another study found that cranberry juice raised urinary oxalate and uric acid supersaturation, which would work in the opposite direction.10European Journal of Clinical Nutrition. Effect of blackcurrant-, cranberry- and plum juice consumption on risk factors associated with kidney stone formation
The second study also noted that cranberry juice acidifies urine, which could help dissolve certain stone types like struvite or brushite, but would be unhelpful or even harmful for uric acid stones, which form in acidic urine. Given these conflicting signals, cranberry juice is not a reliable choice for general stone prevention. If you enjoy it and your stones are calcium oxalate, small amounts are unlikely to cause harm. But it is not a therapeutic recommendation the way lemon water is.
Mineral Water
Not all water is created equal when it comes to kidney stones. Mineral waters rich in bicarbonate and magnesium have shown favorable effects on urinary chemistry. In one study, a bicarbonate-rich mineral water raised urine pH, increased magnesium and citrate excretion, and lowered calcium oxalate supersaturation, effectively counterbalancing any increase in urinary calcium from the water’s mineral content.11PubMed. Influence of a mineral water rich in calcium, magnesium and bicarbonate on urine composition and the risk of calcium oxalate crystallization A clinical study in patients with recurrent calcium oxalate stones found that bicarbonate-containing mineral water significantly lowered the risk of both calcium oxalate and uric acid stone formation, leading the researchers to recommend it for long-term stone prevention.12PubMed. Clinical study on the effect of mineral waters containing bicarbonate on the risk of urinary stone formation in patients with multiple episodes of CaOx-urolithiasis
If you are buying bottled water and live in an area where tap water quality is poor or mineral content is very low, choosing a brand with higher bicarbonate and magnesium may offer a small extra benefit. This is not a reason to spend money on expensive imported water, but if you are already buying bottled water, checking the label for bicarbonate content is a free optimization. Be aware that mineral waters very high in calcium without corresponding magnesium or bicarbonate could theoretically increase calcium excretion without the protective counterbalance.
Apple Cider Vinegar and Other Vinegar Drinks
Apple cider vinegar has become one of the trendier kidney stone “remedies” online. The theoretical basis comes from a study that found daily vinegar consumers had higher urinary citrate, lower urinary calcium, and lower crystallization risk indices than non-consumers. Animal experiments from the same research group suggested that acetate, the active component in vinegar, promoted gene expression changes in kidney cells that enhanced citrate excretion and reduced calcium excretion.13PubMed Central. Dietary vinegar prevents kidney stone recurrence via epigenetic regulations
That sounds promising, but when researchers actually tested apple cider vinegar in a randomized crossover trial in humans, it did not significantly change any 24-hour urinary parameters, including pH and urine volume.14PubMed Central. Apple cider vinegar for prevention of urinary lithiasis (APUL): a randomized crossover trial The observational finding that vinegar users had better urine chemistry may reflect broader dietary patterns rather than vinegar itself. In short, the human trial evidence is not there yet. Drinking diluted apple cider vinegar in small amounts is unlikely to harm you, but the expectation that it dissolves or prevents stones is ahead of the science.
Milk and Dairy Drinks
Many stone patients instinctively avoid milk because their stones contain calcium, but this is one of the most persistent misconceptions in kidney stone management. Dietary calcium actually binds to oxalate in the gut, preventing oxalate from being absorbed into the bloodstream and eventually ending up in the urine. Increasing calcium intake from below 400 mg to 800 mg daily may decrease oxalate absorption enough to lower urinary oxalate excretion.15PubMed. Substituting milk for apple juice does not increase kidney stone risk in most normocalciuric adults who form calcium oxalate stones A larger analysis of U.S. adults confirmed this relationship, finding that dietary calcium’s ability to bind oxalate in the gut reduced downstream urinary oxalate levels.16PubMed Central. Association between milk consumption and kidney stones in U.S. adults: results from NHANES 2007–2018
The practical takeaway: drinking milk with meals is more protective than avoiding it. The timing matters because calcium needs to be in the gut at the same time as oxalate-rich foods to bind them. Drinking a glass of milk between meals does not have the same binding effect. Calcium supplements, as opposed to dietary calcium from food, may behave differently and have sometimes been linked to higher stone risk when taken on an empty stomach, so food-based calcium is preferred.
Sports and Electrolyte Drinks
Electrolyte drinks like Gatorade are often marketed as superior hydration, but their effect on stone risk is mostly neutral. A study testing a popular sports drink found that it raised urinary pH, sodium, and chloride while lowering uric acid, but did not change urinary volume, calcium, or citrate compared to water.17PubMed. Effect of carbohydrate-electrolyte sports beverages on urinary stone risk factors A separate study of two sports drinks found no significant differences in sodium excretion, calcium excretion, or any supersaturation values.18PubMed. Effect of two sports drinks on urinary lithogenicity The added sodium in these drinks is a mild concern, since sodium increases calcium excretion over time, but the effect in the short term does not appear dramatic. If you are exercising heavily and need electrolyte replacement, these drinks are fine. As a daily hydration strategy for stone prevention, water or water with lemon is a better choice simply because it avoids unnecessary sugar and sodium.
Sugary Soft Drinks and What to Avoid
Sugar-sweetened sodas are among the worst beverages for kidney stone formers. The sugar drives up urinary calcium excretion, and cola-type drinks contain phosphoric acid, which complicates urine chemistry further. Laboratory analysis of artificial urine showed that adding phosphoric acid at concentrations consistent with cola consumption increased the formation of certain crystal complexes and shifted the conditions toward greater stone-forming potential.19Scientific Reports. Consumption of soft drinks rich in phosphoric acid versus struvite crystallization from artificial urine The picture is clearest for colas, but any heavily sweetened beverage, including sweetened iced teas and fruit punches, adds sugar that can work against you. Diet sodas are less clearly harmful, but they provide none of the positive urinary chemistry changes you get from lemon water, coffee, or bicarbonate-rich mineral water.
Baking Soda for Uric Acid Stones
If your stone is uric acid rather than calcium oxalate, the strategy shifts. Uric acid crystals form in acidic urine, so the goal is to raise urine pH into the range of roughly 6.5 to 7.0. Potassium citrate is the standard prescription for this, but sodium bicarbonate (baking soda dissolved in water) can also alkalize urine and has been described as highly effective for both dissolving existing uric acid stones and preventing recurrence.20PubMed. Uric acid nephrolithiasis: current concepts and controversies This is one of the few scenarios where a drink can actually dissolve a stone that has already formed, rather than just preventing new ones. However, baking soda adds a lot of sodium, which is problematic for people with high blood pressure or heart failure. It also should not be used for calcium phosphate stones, which form in alkaline urine, where raising pH would make things worse. This is a case where knowing your stone type before self-treating is essential.
Herbal Teas and Chanca Piedra
Chanca piedra, also known as Phyllanthus niruri or “stonebreaker,” is a tropical plant whose tea has been used in South American folk medicine for kidney stones. Some clinical evidence supports it. A study of 56 patients with stones smaller than 10 mm found that the average stone count per patient dropped from about 3.2 to 2.0 after treatment, with reductions in urinary oxalate among patients who had high levels and decreases in uric acid among those with elevated uric acid.21PubMed Central. Effect of phyllanthus niruri on metabolic parameters of patients with kidney stone: a perspective for disease prevention A broader review noted that Phyllanthus niruri appears to interfere with calcium oxalate crystallization while reducing hyperoxaluria and hyperuricosuria, though the authors called for more rigorous randomized controlled trials.22PubMed Central. Phytotherapy in Urolithiasis: An Updated Overview of Current Knowledge
The evidence here is real but limited. Most studies are small, unblinded, or observational. Chanca piedra tea is widely available and appears safe, but expecting it to dissolve a large stone is unrealistic. It may be a reasonable addition to a broader prevention regimen for someone who forms calcium oxalate stones, especially if they prefer herbal options alongside standard medical advice.
Sticking With It Is the Hardest Part
The unsexy truth about drinking to prevent kidney stones is that consistency matters far more than which specific beverage you choose. A study tracking first-time stone patients found that only about half managed to reach the target urine volume of 2.5 liters at six months after being counseled on fluid intake.23PubMed. Factors Associated with Compliance to Increased Fluid Intake and Urine Volume Following Dietary Counseling in First-Time Kidney Stone Patients Patients over 58 and those with lower urinary tract symptoms were less likely to comply. Another study found that the patients who succeeded with higher fluid intake were more likely to prefer water and to enjoy its taste, while those who struggled reported more barriers to drinking enough.24PubMed. Predictors of Reporting Success With Increased Fluid Intake Among Kidney Stone Patients
This is where the variety of acceptable beverages actually helps. If you dislike plain water, rotating between water with lemon, coffee in the morning, an herbal tea in the afternoon, and a glass of milk with dinner can make high fluid intake more sustainable than staring down a jug of plain water all day. The goal is total fluid volume with a composition that favors your urine chemistry. Any combination of the beneficial drinks discussed above beats a perfect plan that you abandon after two weeks.
When Drinks Are Not Enough
For stones already lodged in the ureter, your doctor may prescribe a medication called tamsulosin (an alpha-blocker) to relax the smooth muscle of the ureter and improve passage rates. One comparative study found that patients receiving tamsulosin had an 88% expulsion rate with a mean passage time of 8 days, compared to 72% and 14 days in a group relying on fluid therapy alone.25Journal of Nepalgunj Medical College. Tamsulosin versus Fluid Therapy in Management of Ureteric Stone: A Comparative Study Medications like this work alongside adequate hydration, not instead of it. For larger or more stubbornly lodged stones, lithotripsy or ureteroscopy may be needed. Drinks are one layer of a broader strategy, and for prevention they are arguably the most important layer, but they do have limits that are worth acknowledging honestly rather than overselling what a glass of lemon water can do.