Yes, carbonated water is just as hydrating as still water. The bubbles don’t change how your body absorbs the fluid, and the CDC lists sparkling water alongside tap water as a recommended alternative to sugary drinks. Whether you prefer seltzer, club soda, or sparkling mineral water, you’re getting the same hydration benefit as a glass from the tap.
Why Carbonation Doesn’t Change Hydration
The carbon dioxide dissolved in sparkling water creates carbonic acid, which is what gives it that fizzy bite. But once you swallow it, the gas doesn’t meaningfully alter how quickly water moves through your stomach and into your intestines. A study published in Pharmaceutics found that drinking sparkling water did not result in altered gastric emptying compared to still water. The CO2 bubbles expand and release in your stomach, but the water itself follows the same absorption pathway it always does.
Your body doesn’t distinguish between water molecules that arrived with bubbles and those that didn’t. The small intestine absorbs the fluid the same way regardless. The only real difference is that released gas in your stomach can make you feel fuller, which brings up the one practical caveat worth knowing about.
Carbonation Can Make You Drink Less
The gas released from carbonated water distends your stomach, creating a feeling of fullness that plain water doesn’t. Research published in BMJ Nutrition, Prevention & Health found that this distension of the stomach induces satiety and may reduce hunger. That’s potentially useful if you’re trying to eat less, but it can work against you if you’re trying to stay well hydrated during exercise or in hot weather.
If you find yourself unable to drink enough sparkling water to keep up with your fluid needs, that’s not a hydration problem with the water itself. It’s a volume problem. Switching to still water when you need to drink large amounts quickly, like during a workout, is a simple fix.
Seltzer, Club Soda, and Mineral Water
These three types of carbonated water differ mainly in what’s dissolved in them besides CO2. Seltzer is the simplest: plain water with added carbonation and nothing else. Club soda contains added minerals like sodium bicarbonate, sodium citrate, and potassium sulfate, which give it a slightly salty, mineral taste. Sparkling mineral water comes from natural springs or wells and contains naturally occurring minerals like salts and sulfur compounds, sometimes bottled directly at the source.
All three hydrate equally well. The small amounts of sodium in club soda can actually help with fluid retention, similar to how sports drinks work, though the quantities are modest. None of these contain sugar or calories unless something has been added, and all count toward your daily fluid intake.
What About Your Teeth?
Plain carbonated water is more acidic than still water because dissolved CO2 forms carbonic acid. Commercial carbonated waters typically have a pH between 4.18 and 5.87. Tooth enamel begins to dissolve at a pH below 5.5, which means some sparkling waters technically cross that threshold.
That said, the erosive potential of plain sparkling water is far lower than that of sodas, citrus juices, or flavored sparkling waters with added citric acid. A study in the Korean Journal of Orthodontics found that carbonated water did cause measurable enamel changes on already-etched tooth surfaces in a lab setting, but researchers noted that studies specifically focused on plain carbonated water remain scarce. Your saliva naturally buffers acidity in your mouth, so drinking sparkling water with meals or not swishing it around your teeth minimizes any risk. Flavored varieties with citric acid are a different story and are significantly more erosive.
No Effect on Bone Density
The idea that carbonated drinks weaken bones comes from research on cola, not sparkling water. Cola contains phosphoric acid, which may interfere with calcium absorption. Plain carbonated water does not. A community-based study published in the American Journal of Public Health examined older women and found that bone mineral density was not associated with intake of any type of carbonated beverage after adjusting for age, obesity, calcium intake, exercise, and other factors. Modest intake of carbonated beverages does not appear to have adverse effects on bone density.
Digestive Comfort
Bloating and gas are the most common complaints about carbonated water, and they’re real but generally mild. The CO2 has to go somewhere once it’s released in your stomach, and that means burping or, occasionally, some abdominal discomfort. Research suggests that symptoms related to gastric distress typically appear only when drinking more than 300 ml (about 10 ounces) of a carbonated fluid at once.
If you have acid reflux, the evidence is mixed. Some surveys have found a weak association between carbonated beverages and reflux symptoms, but the overall evidence is contradictory and the studies often had methodological limitations. If sparkling water consistently triggers your reflux, that’s worth paying attention to, but there’s no strong clinical basis for avoiding it preemptively. For most people, carbonated water moves through the digestive system without issues.