To take baking soda as an antacid, dissolve half a level teaspoon in at least 4 ounces (half a glass) of water and drink it after the powder has fully dissolved. This is the standard single dose for relieving heartburn or an upset stomach, and you can repeat it every two hours if needed. But there are strict daily limits, important timing details, and situations where you shouldn’t take it at all.
The Standard Dose for Heartburn
The basic instructions are simple: half a level teaspoon of baking soda in half a glass of cold water, taken after meals. Make sure the powder is completely dissolved before you drink it. Undissolved baking soda can cause a sudden release of gas in the stomach, which is uncomfortable and, in rare cases, dangerous.
If you’re under 60, you can take up to six half-teaspoon doses in a 24-hour period, spacing them at least two hours apart. If you’re 60 or older, the maximum drops to three half-teaspoon doses per day. The lower limit for older adults exists because kidney function typically declines with age, making it harder for the body to clear the extra sodium and bicarbonate.
Do not use baking soda as an antacid for more than two weeks. If your heartburn keeps returning, that’s a signal something else is going on and the baking soda is just masking it.
Why the Sodium Content Matters
A single teaspoon of baking soda contains roughly 1,259 milligrams of sodium. Even a half-teaspoon dose delivers about 630 milligrams, which is more than a quarter of the 2,300-milligram daily sodium limit most health guidelines recommend. If you’re taking multiple doses throughout the day, you can easily exceed your entire daily sodium allowance from baking soda alone, before counting anything you eat.
That sodium load is a serious concern if you have high blood pressure, heart failure, kidney disease, or any condition where your body retains fluid. It can also interact with prescription medications, particularly those for heart or blood pressure management. People on sodium-restricted diets should avoid using baking soda as an antacid entirely.
What Happens if You Take Too Much
Baking soda overdose is not just a theoretical risk. It shifts the blood’s pH too far toward the alkaline side, a condition called metabolic alkalosis. The symptoms range widely in severity. Mild cases cause weakness, dizziness, and stomach problems. Severe cases, documented in emergency medicine case reports, have involved seizures, fainting, dangerous heart rhythm changes, and even cardiac arrest.
One published case described a 39-year-old man who had been taking baking soda regularly for a week and showed up to an emergency room with generalized weakness, daily headaches, and dizzy spells. He lost consciousness while standing in the lobby. The underlying problem was that excessive bicarbonate had thrown off his blood chemistry, depleting potassium and spiking sodium levels.
The risk is highest when people use baking soda frequently, take large doses, or combine it with a diet already high in sodium. Symptoms to watch for include persistent nausea, muscle twitching, confusion, and unusual fatigue. These can develop gradually over days of overuse, not just from a single large dose.
Taking Baking Soda for Exercise Performance
Athletes sometimes use baking soda (often called “bicarb loading”) to buffer the lactic acid that builds up during high-intensity exercise. This is a completely different use case from heartburn relief, with different dosing and timing.
The protocol recommended by the Australian Institute of Sport calls for 200 to 400 milligrams per kilogram of body weight, taken two to two and a half hours before exercise. For a 70-kilogram (154-pound) person, that works out to roughly 14 to 28 grams, a dramatically larger amount than the antacid dose. It should be taken alongside a small carbohydrate-rich meal, which helps reduce stomach distress.
At these doses, the buffering effect kicks in within about two hours and lasts three to four hours. The most common side effect is gastrointestinal discomfort, including bloating, nausea, and diarrhea. This is why sports nutrition guidelines emphasize testing your individual tolerance well before any competition day. Starting at the lower end of the dose range and working up is the standard approach.
Tips for Reducing Side Effects
The most common complaint with any oral baking soda dose is stomach bloating and gas. When baking soda hits stomach acid, it produces carbon dioxide rapidly. A few practical steps can minimize this:
- Always dissolve fully. Stir the powder into water until no grit remains at the bottom of the glass. Drinking undissolved powder concentrates the gas production.
- Use cold water. Cold water holds dissolved gas better than warm water, which means less immediate bloating.
- Take it after eating, not on a completely empty stomach. Food in the stomach slows the reaction slightly and reduces the sudden gas surge.
- Don’t take it when you’re already very full. The gas expansion on top of a large meal can cause significant discomfort and, in extreme cases, has been linked to stomach rupture in people who consumed very large amounts.
Who Should Avoid It
Baking soda is not a good antacid choice for everyone. People with high blood pressure, heart failure, or kidney problems should avoid it because of the sodium load. Pregnant women should also skip it, as the sodium can worsen swelling and fluid retention. Children under six should not take it at all, and children between 6 and 12 should only take a quarter to half teaspoon per dose.
If you take any prescription medications regularly, check for interactions before using baking soda. It changes the acidity of your stomach and urine, which can affect how quickly your body absorbs or eliminates certain drugs. This is especially relevant for heart medications, antibiotics, and anything where timing and absorption matter.
For occasional heartburn, baking soda works fast and costs almost nothing. But it’s a short-term fix, not a treatment plan. If you find yourself reaching for it more than a few times a week, the heartburn itself needs attention rather than repeated neutralization.