Baking Soda for Heartburn: Does It Work? Dose and Risks

A sourced check on baking soda in water for occasional heartburn: the label dose, when to take it after a meal, the sodium in mg and who should ask a doctor first.

Most people searching this want one thing: does a spoon of baking soda in water stop heartburn? Here's where the viral version goes wrong. It skips the dose, the water minimum and the sodium. We found no trial of baking soda for heartburn, so the evidence is limited. We also found no sourced onset time.

Readers and recipe reviewers describe it as an old household habit for occasional heartburn, and a few say it is the only thing that has worked for them. Those are personal reports, not evidence. The same comments keep repeating one warning: measure a level half teaspoon, never a tablespoon.

The full dose chart is in how much baking soda in water, the risks are in baking soda side effects, and the sodium math is in how much sodium in baking soda water. For timing outside heartburn, see the best time to drink baking soda water. We link to them instead of repeating their tables.

The Food Science / Lab Kitchen Note

Baking soda is sodium bicarbonate, a base. Stomach acid is hydrochloric acid. When they meet, they react:

NaHCO3 + HCl → NaCl + H2O + CO2

That's an antacid doing its job: acid is used up and turned into salt, water and carbon dioxide. The CO2 is a gas, which is why the mild effects MedlinePlus lists include gas. MedlinePlus and the label both say not to take it on an overly full stomach.

Now the sodium. Our dose chart uses about 27,360 mg of sodium per 100 g of baking soda (273.6 mg per gram) and 4.6 g per teaspoon. For 1.15 g, that's about 315 mg. For the 2.3 g label dose, it's about 630 mg. Those two figures are our calculation. The package figure quoted by People's Pharmacy and a recipe reviewer is 616 mg per 1/2 tsp.

The FDA puts the sodium Daily Value at less than 2,300 mg a day, says Americans average about 3,400 mg, and names baking soda as an additive that contains sodium. Against 2,300 mg, our 315 mg glass is 13.7%, and the label's 616 mg is about 27%.

The label also sets a daily ceiling. The Arm & Hammer antacid page gives a maximum of seven 1/2 teaspoons in 24 hours, or three if you're over 60. By the 616 mg figure, that's about 4,312 mg of sodium at seven doses and 1,848 mg at three. The page itself gives no sodium content.

Baking soda vs other antacids (data only)

This is a comparison of published data, not a taste test or a trial of our own. Where no source gave a number, the table says so.

MedlinePlus says all antacids work about equally well for heartburn that happens once in a while, and that the side effects differ. NIDDK says antacids are for mild heartburn, not for daily use or severe symptoms unless you've talked with your doctor. It also describes two other drug types. H2 blockers lower the acid your stomach makes and heal the esophagus less effectively than PPIs. PPIs lower acid production, treat GERD symptoms better than H2 blockers and can heal the esophageal lining in most people with GERD. No antacid brand names or onset times are given, so we give none either.

What the studies show

A 2022 case review in the Journal of Eating Disorders looked at spontaneous gastric rupture after binge eating or a large meal. It covered two new cases plus 36 published ones. Sodium bicarbonate was involved in 10 of the 36, overall mortality was 41.6% and about 47.2% had an eating disorder. It's a case review, not a trial, and it gives no threshold for a normal glass. What it does show is why the labels say not to take this when overfull.

On whether it works, the answer is thinner than the viral posts suggest. MedlinePlus lists sodium bicarbonate as an antacid for heartburn and acid indigestion, and NIDDK lists antacids for mild heartburn. But we found no trial of baking soda itself. A commercial site reviewed by a physician assistant, Optum Perks, says evidence is limited and that antacids or PPIs may be better options. It also gives a different dose from the label, so we don't use it for dosing.

When heartburn isn't occasional

MedlinePlus says to call your provider if symptoms come every day or at night, or if you need antacids on most days. Chest pain, trouble swallowing, vomiting, dark stools or unexplained weight loss are the other flags it names. Baking soda isn't a plan for any of those. If symptoms don't go away with over-the-counter medicines, NIDDK says to talk with your doctor.

Spacing matters too, and the sources disagree. The MedlinePlus sodium bicarbonate page says take it at least 2 hours apart from other medicines. Its general antacid page says other medicines 1 hour before or 24 hours after antacids. Ask a pharmacist which applies to yours.

Common mistakes

Using a tablespoon

Reviewers warn about this one most. The label is a level 1/2 teaspoon. Level it with a knife.

Mixing up the water

One popular recipe uses 1 cup of water where the label says 4 fl oz (120 mL). Other sites give different doses again. Stick to the label dose and the MedlinePlus minimum of 4 fl oz.

Drinking it on a full stomach

Both the label and MedlinePlus say not to. Wait the 1 to 2 hours, and sip.

Substitutes and swaps

Storage

Mix one glass and drink it. We found no sourced shelf life for the mixed drink, so we give no duration. Make-ahead tip: measure and level the dry soda into the spoon, and add water only when you're ready to drink.

Nutrition note

Values on the recipe card are estimates calculated from our dose chart's figures (about 27,360 mg of sodium per 100 g, 4.6 g per teaspoon), per glass of 8 fl oz with 1/4 tsp (1.15 g), not measured. The glass is water and baking soda, so calories, carbohydrate, protein, fat, sugars and fiber are all zero. Sodium is about 315 mg, or 13.7% of 2,300 mg.