Does Mineral Water Make You Pee More?

Mineral water does appear to increase urine output, at least modestly. A 2023 systematic review found that every study it examined reported an increase in urine production following consumption of natural mineral water, with some showing the effect after a single serving.¹ The real story, though, is less about whether you pee more and more about why. The answer depends heavily on the mineral profile of the water, whether it is carbonated, and what you were drinking before.

What the Research Shows About Mineral Water and Urine Volume

When researchers give people mineral water and measure what happens, urine output consistently goes up. That might sound obvious since any water you drink has to go somewhere, but the question is whether mineral water produces more urine than the same volume of plain tap or low-mineral water. The systematic review mentioned above looked across multiple studies and found the answer was yes. One trial tested three different types of water in men and found that urinary output increased with all three, but the mineral-rich varieties had distinct effects on urine composition.²

There is an important distinction here between total urine volume and how well the water actually hydrates you. A landmark trial that created a “beverage hydration index” found that sparkling water, despite being a type of mineral water, did not produce different cumulative urine output at four hours compared to still water.³ In other words, sparkling water kept people just as hydrated as flat water over that time frame. The drinks that did cause people to pee significantly more were things like alcohol, while beverages with calories or electrolytes (milk, orange juice) tended to be retained longer. This suggests that carbonation alone is not the main driver of increased urination. What matters more is what’s dissolved in the water.

The Mineral Content Is What Makes the Difference

Not all mineral waters are the same. A bottle of lightly mineralized spring water from one brand can contain a fraction of the dissolved solids found in a heavily mineralized water from another. The minerals that matter most for urine production are sodium, bicarbonate, calcium, and magnesium. Each of these affects how your kidneys process the water and what they excrete.

Sodium is the most straightforward. When you drink a sodium-rich mineral water, your kidneys need to excrete that extra sodium, and they pull water along with it to keep the urine dilute enough. A study comparing sodium-bicarbonated mineral water with low-mineral water found that urinary sodium concentration was significantly higher with the mineral water, even though total mineral excretion was otherwise similar between the two.⁴ That study also found the mineral water lowered aldosterone, a hormone that tells your kidneys to hold onto sodium and water. Less aldosterone means your body is less inclined to retain fluid.

Calcium and magnesium play their own roles. A trial using mineral water rich in all three minerals (calcium, magnesium, and bicarbonate) found that people on their usual diet had significantly higher urinary volume when drinking the mineral water compared to their baseline.⁵ The effect was not just about peeing more; the composition of the urine changed in ways that mattered for health, including higher citrate excretion and lower risk of certain crystal formations.

How Bicarbonate Changes Your Urine Chemistry

Bicarbonate-rich mineral water has gotten particular attention from researchers because it shifts the acid-base balance of your urine. When you drink water high in bicarbonate, your urine becomes less acidic. A review of the clinical evidence found that the key effects of bicarbonate mineral water include a rise in urine pH and a substantial reduction in the body’s net acid excretion.⁶ Separate research confirmed the same pattern, showing that bicarbonate-rich mineral water increased blood bicarbonate levels and base excess alongside the urine changes.⁷

Why does this matter for how often you pee? The kidneys are doing extra work to process and excrete the bicarbonate load. That processing involves moving more water through the system. The effect is modest for most people, but if you’re someone who drinks several glasses of high-bicarbonate mineral water daily, the cumulative increase in urine output can be noticeable.

This is also partly why comparing mineral water to tap water in studies can produce inconsistent results. Tap water composition varies enormously by location. In a city with already mineral-rich tap water, the difference between tap and bottled mineral water might be trivial. In a city with very soft, low-mineral tap water, the gap widens.

Does Carbonation Itself Make You Pee More?

Many people assume the bubbles in sparkling water are responsible for increased urination. The evidence for this is surprisingly thin. As the beverage hydration index study showed, sparkling water and still water produced essentially identical urine output over four hours under resting conditions.³ The carbon dioxide gas itself does not appear to change how your kidneys handle water in any meaningful way when you are just going about your day.

What carbonation does affect is your stomach. Sparkling water creates transient pressure events in the upper digestive tract, and research has shown this can speed up how quickly substances are absorbed from the gut.⁸ However, this faster absorption does not translate to faster kidney processing in a clinically significant way under normal circumstances. Another study found that carbonated water did not alter overall gastric emptying speed at all, though it did change how food and liquid were distributed within the stomach.⁹

So the carbonation itself is largely a red herring for urination. What carbonated mineral waters often have, though, is a higher mineral content than their flat counterparts, especially sodium and bicarbonate. Those minerals, not the fizz, are what can push your kidneys to produce more urine.

Exercise Changes the Equation

The one situation where carbonation does seem to matter for hydration and urination is during and after exercise. A recent study compared four types of water (plain, carbonated, electrolyte-added, and electrolyte-added carbonated) after exercise. The carbonated water group produced significantly more urine than the other groups, and their net fluid retention was notably lower. People drinking carbonated water also tended to drink less of it, likely because the bubbles created a feeling of fullness. The combination of drinking less and retaining less left the carbonated water group with significantly lower fluid recovery compared to every other group.¹

This is a practical point worth remembering. If you are exercising or sweating heavily and reach for sparkling mineral water to rehydrate, you may end up peeing out more of it and drinking less of it than you would with flat water. Adding electrolytes to carbonated water appeared to counteract the retention problem, bringing it back in line with plain water. The takeaway for athletes or anyone working out in the heat: plain or electrolyte-enhanced water is a better rehydration choice than carbonated mineral water.

Mineral Water and Kidney Stones

One of the most studied applications of mineral water’s diuretic effect is in kidney stone prevention. The logic is straightforward: if mineral water makes you produce more dilute urine, it can reduce the concentration of stone-forming substances. And the research largely supports this, though with caveats about which mineral water you use.

A study that compared mineral water containing calcium and magnesium against tap water found that the mineral water favorably altered several kidney stone risk factors, including oxalate excretion and the relative supersaturation of calcium oxalate, brushite, and uric acid. Tap water also helped, but the mineral water was more effective. It uniquely improved citrate and magnesium excretion, both of which inhibit stone formation. The group that benefited most was male stone formers, in whom nine risk factors improved on the mineral water protocol.¹⁰ The researchers concluded that this type of mineral water deserves consideration as a preventive measure for calcium oxalate kidney stones.

One common worry is that the calcium in mineral water might increase stone risk. The evidence suggests the opposite. The calcium-magnesium-bicarbonate mineral water studied actually decreased the supersaturation of calcium oxalate in urine, even though it modestly increased calcium excretion under controlled diet conditions.¹¹ The extra magnesium and citrate appear to more than compensate for the additional urinary calcium. This parallels a broader finding in nutrition research that dietary calcium generally protects against kidney stones rather than promoting them, because it binds oxalate in the gut before it can reach the kidneys.

A separate trial found that both low-mineral and bicarbonate-alkaline high-calcium mineral water increased diuresis to a similar degree, but the high-calcium water also increased urinary calcium by about 80 milligrams per day. Both groups saw a rise in urinary oxalate alongside the increased volume.¹² The increased volume, though, helps dilute these substances and reduce crystal formation risk overall.

What Your Body Does When Water Hits Your System

Understanding why any water makes you urinate involves a hormone called vasopressin (sometimes called antidiuretic hormone). When you are dehydrated, vasopressin levels rise and tell your kidneys to conserve water. When you drink, vasopressin drops and the kidneys start producing more dilute urine. Research in people who were mildly dehydrated found that spontaneous water drinking returned vasopressin to normal levels and also triggered a significant increase in atrial natriuretic peptide, another hormone that promotes sodium and water excretion by the kidneys.¹³ This hormonal cascade is the basic mechanism behind any fluid producing urine.

Mineral water adds extra layers to this process. The dissolved sodium, bicarbonate, and other minerals create additional osmotic work for the kidneys. Your body tightly regulates the concentration of electrolytes in your blood, so when extra minerals arrive via the gut, the kidneys ramp up their filtration to excrete the surplus, bringing water along for the ride. This is why highly mineralized waters tend to be more diuretic than pure or low-mineral water: they give your kidneys more to process.

That said, the effect is not dramatic for most people drinking typical amounts. If you replace your usual tap water with a moderately mineralized bottled water, you might notice slightly more frequent trips to the bathroom for the first few days. Your body adjusts. If you switch to a heavily mineralized water, one with over 1,500 milligrams of total dissolved solids per liter, the diuretic effect can be more persistent.

Could Mineral Water Irritate Your Bladder?

Some people report needing to urinate more urgently, not just more frequently, when they switch to mineral or sparkling water. This raises a separate question from diuresis: bladder irritation. Carbonated beverages are often listed among “potentially irritating beverages” for people with overactive bladder or lower urinary tract symptoms. A clinical trial that asked women to eliminate coffee, tea, alcohol, carbonated beverages, and artificially sweetened drinks found that even partial reduction in these beverages improved urinary symptoms. Women who cut their intake of irritating beverages roughly in half still saw benefits, though complete elimination proved difficult for most participants.¹⁴

The trouble with that study, and with similar guidance, is that carbonated water was grouped with caffeinated, alcoholic, and artificially sweetened drinks. Caffeine and alcohol are established bladder irritants. Whether the carbonation itself irritates the bladder, or whether the effect is driven by caffeine and alcohol in the same behavioral category, is hard to disentangle. For people without existing bladder issues, sparkling mineral water is unlikely to cause urgency. For those who already deal with overactive bladder, reducing carbonated drinks may help, but cutting out the caffeine and alcohol in the same sweep is probably doing most of the heavy lifting.

Comparing Mineral Water Brands

Because the diuretic effect depends on mineral content, not all mineral waters behave the same. European mineral waters tend to have higher total dissolved solids than many North American brands. A water labeled “natural mineral water” in the EU must come from a protected underground source and maintain a consistent mineral profile, but the actual mineral concentration ranges from barely-there to extremely high.

What to look for on the label if you are curious about the diuretic potential:

Sodium: Waters above roughly 200 mg/L of sodium will tend to increase urinary sodium excretion and pull water along with it.
Bicarbonate: High-bicarbonate waters (above 600 mg/L) are the ones most studied for effects on urine pH and acid-base balance.
Calcium and magnesium: These affect urine composition more than urine volume, but high levels contribute to the overall mineral load the kidneys must handle.
Total dissolved solids: A rough proxy for how “mineral-heavy” the water is. Under 500 mg/L is considered low-mineral. Above 1,500 mg/L is very high.

A lightly mineralized sparkling water with, say, 50 mg/L of total dissolved solids will behave almost identically to tap water for urine output purposes. A heavily mineralized bicarbonate-sodium water at 3,000 mg/L of total dissolved solids is a genuinely different product with different physiological effects.

When More Peeing Is Actually the Point

In urological practice, increased urine volume is often a treatment goal rather than a side effect. People prone to kidney stones are routinely advised to drink enough fluid to produce at least two liters of urine per day, and some clinicians specifically recommend mineral water as a way to achieve this while also improving urine chemistry. The research on calcium-magnesium mineral waters and stone risk supports this approach for calcium oxalate stone formers.¹⁰

For people with recurrent urinary tract infections, dilute urine that flushes bacteria from the bladder more frequently is also considered protective. Mineral water that encourages higher urine output could theoretically help, though the evidence here is less direct than for kidney stones. The main practical barrier is that people who are already bothered by frequent urination, such as those with overactive bladder, may find the increased output counterproductive for their quality of life.

There is also the question of nighttime urination. If you drink mineral water close to bedtime, especially a high-sodium variety, you are more likely to wake up needing to use the bathroom. This is not unique to mineral water, but the modest diuretic boost can make the difference between sleeping through and getting up at 3 a.m. Shifting your mineral water intake earlier in the day is a simple fix if nocturia becomes an issue.

1
PubMed Central. Natural Mineral Water and Diuresis: A Systematic Review
2
PubMed. Effects of drinking water quality on urinary parameters in men with and without urinary tract stones
3
The American Journal of Clinical Nutrition. A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index
4
PubMed. Sodium-bicarbonated mineral water decreases aldosterone levels without affecting urinary excretion of bone minerals
5
PubMed. Influence of a mineral water rich in calcium, magnesium and bicarbonate on urine composition and the risk of calcium oxalate crystallization
6
PubMed Central. Hydration Meets Regulation: Insights into Bicarbonate Mineral Water and Acid-Base Balance
7
Leibniz Universität Hannover. Bicarbonate-Rich Mineral Water and Human Health: Biological Mechanisms and Clinical Evidence
8
PubMed. The Effect of Sparkling Water on Intraluminal Formulation Behavior and Systemic Drug Performance
9
PubMed. Effect of carbonated water on gastric emptying and intragastric meal distribution
10
Urologia Internationalis. Effect of Mineral Water Containing Calcium and Magnesium on Calcium Oxalate Urolithiasis Risk Factors
11
European Journal of Clinical Nutrition. Influence of a mineral water rich in calcium, magnesium and bicarbonate on urine composition and the risk of calcium oxalate crystallization
12
Urologia Internationalis. Urinary Composition and Lithogenic Risk in Normal Subjects following Oligomineral versus Bicarbonate-Alkaline High Calcium Mineral Water Intake
13
PubMed. Effects of hypertonic saline infusion and water drinking on atrial peptide
14
PubMed Central. Does instruction to eliminate coffee, tea, alcohol, carbonated, and artificially sweetened beverages improve lower urinary tract symptoms: A Prospective Trial