Swallowing a small amount of baking soda mixed in water is generally safe for most adults and has been used as a home antacid for decades. The standard dose for heartburn relief is half a teaspoon dissolved in a full glass of cold water. At that amount, it works quickly to neutralize stomach acid. Problems arise when people take too much, use it too frequently, or have certain health conditions that make even small amounts risky.
How Baking Soda Works in Your Stomach
Baking soda is sodium bicarbonate, a salt that becomes alkaline when dissolved in water. When it hits the hydrochloric acid in your stomach, a chemical reaction produces water, salt, and carbon dioxide gas. That reaction is what neutralizes the acid and relieves heartburn or indigestion, sometimes within minutes.
The carbon dioxide is also why you’ll almost certainly burp after drinking it. That gas buildup is the most common side effect, and for most people it’s just mildly uncomfortable. In rare circumstances, though, that rapid gas production can be dangerous, which is why the amount you take and when you take it both matter.
How Much Is Considered Safe
For occasional heartburn, the standard adult dose is half a teaspoon of baking soda powder in a glass of cold water, taken after meals and no more frequently than every two hours. The maximum for adults under 60 is roughly 5 teaspoons of the powder form per day. For adults 60 and older, the limit is cut in half. These limits exist because a single teaspoon of baking soda contains about 1,259 milligrams of sodium, which is already more than half the daily recommended limit for most adults.
Baking soda should not be used as an antacid for more than two weeks straight. If your heartburn keeps coming back, something else is going on and an over-the-counter antacid designed for longer use, or a medical evaluation, would be more appropriate.
The Sodium Problem
Most people focus on the “antacid” part and forget that baking soda is, at its core, a sodium compound. Even a single half-teaspoon dose delivers roughly 630 milligrams of sodium, comparable to a fast-food burger. Taking multiple doses in a day can easily push you well past the 2,300-milligram daily sodium limit recommended for healthy adults.
That sodium load is particularly concerning if you have high blood pressure, heart failure, or kidney disease. In people with chronic kidney disease, sodium bicarbonate can raise systolic blood pressure and increase cardiovascular strain. The kidneys are responsible for clearing excess sodium and maintaining the body’s acid-base balance, so when they aren’t functioning well, even modest amounts of baking soda can cause a buildup that the body can’t correct on its own.
What Happens if You Take Too Much
Taking large or repeated doses of baking soda can push your blood chemistry too far toward the alkaline side, a condition called metabolic alkalosis. Mild cases cause nausea and muscle twitching. More severe cases can lead to headaches, extreme fatigue, confusion, muscle spasms, and even seizures. The alkaline shift also lowers the amount of usable calcium circulating in your blood, which is what triggers the muscle and nerve symptoms.
Potassium levels can drop at the same time, causing weakness and, in serious cases, heart rhythm abnormalities. These complications are uncommon at normal doses but become a real risk when people treat baking soda like a harmless kitchen ingredient and take tablespoons instead of half-teaspoons.
A Rare but Serious Risk: Stomach Rupture
Case reports in the medical literature document spontaneous stomach rupture after people took baking soda following a very large meal or a binge-eating episode. The mechanism is straightforward: a stomach already stretched to capacity gets hit with a sudden surge of carbon dioxide gas from the chemical reaction. The combination of food volume, gas pressure, and weakened stomach wall tone can cause the stomach to tear. This is exceedingly rare, but it’s the reason you should avoid taking baking soda on a very full stomach or after eating an unusually large amount of food.
Who Should Avoid It Entirely
Children under 5 should never be given baking soda. The FDA revised product labeling in 1990 after reports of seizures and respiratory depression in young children, including a 6-week-old infant whose mother had been giving him a pinch of baking soda in water to help with burping. Children ages 6 to 12 can use it, but only at a quarter to half-teaspoon dose and only occasionally.
Adults with kidney disease, high blood pressure, or heart failure should avoid it because of the sodium load and its effects on blood pressure and fluid balance. If you take prescription medications regularly, keep in mind that baking soda changes the acidity of your stomach and can alter how well your body absorbs certain drugs. Spacing baking soda at least two hours away from other medications is a general precaution, but the safer approach is to use a commercial antacid that’s been formulated to minimize these interactions.
Baking Soda vs. Store-Bought Antacids
Baking soda works, but it’s a blunt instrument compared to over-the-counter antacids. Products like calcium carbonate tablets deliver a controlled, pre-measured dose with far less sodium. They’re also formulated to avoid the sudden gas surge that baking soda produces. For occasional, mild heartburn when you have nothing else on hand, a half-teaspoon in water is a reasonable short-term fix. For anything recurring, a purpose-built antacid is more predictable, easier to dose correctly, and less likely to cause side effects.