The right amount of sodium bicarbonate depends entirely on why you’re taking it. For occasional heartburn, the standard adult dose is about half a teaspoon dissolved in water. For athletic performance, the dose is calculated by body weight and taken hours before exercise. For managing a chronic condition like kidney disease, doses are prescribed based on blood test results. Each use has its own safe range, and the sodium content in baking soda makes it easy to overshoot safe limits without realizing it.
For Occasional Heartburn
The typical adult dose for heartburn relief is half a teaspoon (about 2.4 grams) of baking soda dissolved in a full glass of water. This neutralizes stomach acid quickly, usually within minutes. You can repeat this dose every two hours if needed, but you should not exceed seven half-teaspoon doses in a 24-hour period if you’re under 60, or three doses if you’re over 60.
This is strictly a short-term fix. Using baking soda for heartburn for more than two weeks straight can disrupt your body’s acid-base balance. If you need relief that often, an over-the-counter antacid tablet is a safer choice because it delivers a controlled, lower dose of sodium.
How Much Sodium You’re Actually Getting
One teaspoon of baking soda contains about 4.8 grams of sodium bicarbonate, which delivers roughly 1,360 milligrams of elemental sodium. That’s nearly 60 percent of the 2,300 mg daily sodium limit recommended for most adults, packed into a single teaspoon. Even half a teaspoon adds about 680 mg of sodium to your day, equivalent to eating a fast-food burger.
By comparison, a standard 650 mg sodium bicarbonate tablet contains only about 178 mg of elemental sodium. Tablets give you much more precise control over your intake, which matters if you’re watching sodium for blood pressure or heart health.
For Athletic Performance
Athletes use sodium bicarbonate to buffer lactic acid during high-intensity exercise lasting one to seven minutes (think rowing, swimming, sprinting, or repeated intervals). The dose is weight-based: 200 to 400 mg per kilogram of body weight, taken with a small carbohydrate-rich meal about two to two and a half hours before exercise. For a 70 kg (154 lb) person, that works out to 14 to 28 grams, a substantial amount.
The Australian Institute of Sport, which classifies sodium bicarbonate as a Group A supplement (strong evidence of benefit), recommends aiming for the higher end of that range (300 to 400 mg/kg) if you haven’t had time to test your individual tolerance. At that dose, blood buffering capacity increases enough to be performance-enhancing, and the effect lasts three to four hours.
Gastrointestinal distress is the main barrier. Nausea, bloating, cramping, and diarrhea are common at these doses. A multi-day loading protocol can reduce gut problems: 500 mg/kg per day split into five even doses taken with meals and snacks for up to five days before competition, plus a smaller “top-up” dose of around 100 mg/kg on race day. This builds up buffering capacity more gradually and is easier on the stomach.
For Chronic Kidney Disease
People with chronic kidney disease often develop metabolic acidosis, a condition where the blood becomes too acidic because the kidneys can no longer filter acid efficiently. International guidelines recommend starting oral bicarbonate supplementation when blood bicarbonate levels drop below 22 mEq/L, with the goal of bringing them back into the 24 to 26 mEq/L range.
The typical starting dose is 650 mg taken twice daily, providing about 15.5 mEq of bicarbonate per day. From there, the dose is adjusted based on follow-up blood work. Clinical studies have used doses ranging from 0.5 to 1.0 mEq per kilogram of body weight per day, with some trials going up to 3,000 mg daily. This is not something to self-dose. Your nephrologist sets the amount based on lab results and adjusts it over weeks.
Who Should Avoid It
Because sodium bicarbonate loads your body with sodium, it causes water retention. That makes it risky if you have heart failure, high blood pressure, kidney disease, liver disease, or swelling in your legs and feet. People on sodium-restricted diets should be especially cautious, since even a single antacid dose delivers a meaningful chunk of daily sodium.
Sodium bicarbonate also raises the pH of your stomach, which can interfere with how your body absorbs certain medications. Some antibiotics, HIV medications, and cancer drugs require an acidic stomach environment to dissolve properly. If you take any prescription medications, check whether they interact before using baking soda, even occasionally.
Pregnant women with toxemia (a condition involving high blood pressure and swelling) should avoid it, as should anyone with intestinal bleeding or symptoms of appendicitis, since it can worsen both conditions.
Signs You’ve Taken Too Much
Overdoing sodium bicarbonate can push your blood pH too high, a condition called metabolic alkalosis. Early symptoms include nausea, vomiting, and muscle twitching. More severe cases cause confusion, hand tremors, and an irregular heartbeat. Case reports in medical literature describe serious cardiac events in people who consumed large amounts of baking soda, sometimes just a few tablespoons dissolved in water.
The risk is highest when people use household baking soda rather than tablets, because it’s difficult to measure precise amounts with a kitchen spoon. If you’re using baking soda regularly for any purpose, switching to pre-measured tablets reduces the chance of accidentally taking too much. A standard 650 mg tablet delivers a controlled dose that’s roughly one-seventh of what you’d get from a level teaspoon of powder.