Eating small amounts of baking soda is generally safe for most adults. People have used it for decades as a quick antacid, and it’s a common ingredient in baked goods. But baking soda is far from harmless in larger quantities. A single teaspoon contains about 1,259 mg of sodium, which is over half the daily recommended limit, and swallowing too much at once can cause serious complications including stomach rupture.
Why People Eat Baking Soda
Baking soda (sodium bicarbonate) is alkaline, so it neutralizes stomach acid on contact. That’s why some people dissolve a small amount in water to relieve heartburn or indigestion. It works fast, often within minutes, which makes it a tempting home remedy when you don’t have antacids on hand.
Athletes also use it. When your muscles produce acid during intense exercise, having extra bicarbonate in your blood helps buffer that acid and delay fatigue. The Australian Institute of Sport recognizes sodium bicarbonate as a legitimate performance supplement, with typical doses ranging from 200 to 400 mg per kilogram of body weight taken two to three hours before competition. For a 150-pound person, that works out to roughly 14 to 27 grams, a substantial amount that requires careful timing and preparation.
The Sodium Problem
One teaspoon of baking soda delivers roughly 1,259 mg of sodium. The daily recommended cap for most adults is 2,300 mg, so a single teaspoon gets you past the halfway mark before you’ve eaten any food. If you’re using baking soda regularly as an antacid, you could easily exceed your sodium limit every day without realizing it.
Excess sodium raises blood pressure and increases fluid retention. For anyone managing high blood pressure, heart failure, or kidney problems, this extra sodium load is particularly risky. During pregnancy, the sodium can contribute to edema and excessive weight gain, which is why some experts recommend pregnant women use alternative antacids instead.
What Happens if You Take Too Much
Overdoing it with baking soda pushes your blood chemistry toward a condition called metabolic alkalosis, where your blood becomes too alkaline. Symptoms of a baking soda overdose include nausea, vomiting, diarrhea, constipation, muscle spasms, muscle weakness, irritability, frequent urination, and in severe cases, convulsions. If the vomiting and diarrhea aren’t controlled, dangerous dehydration and electrolyte imbalances can develop, potentially triggering heart rhythm disturbances.
There’s also a rarer but more dramatic risk: stomach rupture. When baking soda hits stomach acid, it rapidly generates a large volume of carbon dioxide gas. Normally your stomach handles this fine. But if your stomach is already full from a large meal or heavy drinking, the sudden gas buildup can create dangerous pressure. Poison Control documents a case where a 54-year-old woman drank half a glass of baking soda after a big meal and immediately felt a stabbing pain, as if something had exploded inside her. Doctors found a two-inch tear in her stomach wall. This is uncommon, but it underscores a simple rule: never take baking soda on a very full stomach.
Medication Interactions
Baking soda changes the pH of your stomach and urine, which can alter how your body absorbs and eliminates certain drugs. The Mayo Clinic lists over 30 medications that interact with sodium bicarbonate. These include common drugs like thyroid medication (levothyroxine), the antibiotic ciprofloxacin, the antifungal ketoconazole, and the heart medication digoxin. It can also affect how your body processes amphetamine-based medications.
The interactions work in different ways. Some medications need an acidic stomach to be absorbed properly, so neutralizing that acid with baking soda reduces their effectiveness. Others are cleared from your body through urine, and because baking soda makes urine more alkaline, those drugs can build up to higher levels than intended. If you take any prescription medications, check for interactions before using baking soda as an antacid.
Stomach Side Effects in Athletic Use
Athletes who use baking soda for performance know the biggest drawback well: gastrointestinal distress. Nausea, stomach pain, diarrhea, and vomiting are common, typically peaking about 90 minutes after ingestion. Taking it with a small carbohydrate-rich meal and plenty of fluid (roughly 10 ml per kilogram of body weight) helps reduce symptoms. Some athletes use enteric-coated capsules, which resist stomach acid and dissolve in the intestine instead, further cutting down on gut problems. Spreading the dose across multiple smaller portions over two to three hours before exercise also helps.
How to Use It Safely
If you’re using baking soda occasionally for heartburn, keep the amount small: half a teaspoon dissolved in at least four ounces of water. Don’t take it on a full stomach, and don’t use it as a daily antacid. The sodium adds up quickly, and regular use can mask underlying conditions like acid reflux that benefit from proper treatment.
Avoid baking soda as a remedy if you’re pregnant, have high blood pressure, have kidney disease, or take prescription medications without first checking for interactions. Children are also more vulnerable to overdose simply because of their smaller body size. If someone has ingested a large amount and shows symptoms like muscle spasms, repeated vomiting, or confusion, contact Poison Control (1-800-222-1222 in the U.S.) or seek emergency care.