Baking Soda for the Body: Stomach Acid, Teeth, Odor, Itch, and the Things It Does Not Do

A quarter teaspoon dissolved completely in 8 ounces of water, sipped slowly, for an adult with heartburn or a sour stomach after a meal. It neutralizes stomach acid in minutes and the relief lasts an hour or two; repeat once after two hours if needed, and stop at a couple of days. Fully dissolved matters: undissolved powder on a full stomach makes gas fast enough to hurt. Not for children, not for anyone on a low-sodium diet or with kidney or heart disease, not in pregnancy, and reflux that comes back for weeks is a doctor's problem, not a baking soda habit.

Not the next-day kind. The soreness after hard work is muscle damage repairing itself, not lactic acid, and baking soda does nothing for it. What the research does show is a small edge in short, all-out efforts of one to ten minutes when athletes take a large dose (3 to 4 teaspoons for a 150 pound adult) an hour or two before, because bicarbonate buffers the acid of that kind of effort; the price is nausea and diarrhea in a lot of people, and it is not a thing to do for a day of splitting wood. A quarter teaspoon in water before work settles the stomach and does nothing for performance.

A teaspoon of baking soda with a few drops of water stirred to a paste, on a soft brush, gently, for two minutes, then rinse well. It is mildly abrasive, so it lifts plaque and surface stains and it neutralizes the acids that feed decay, but it has no fluoride, so it is a few-times-a-week addition to a fluoride toothpaste, not a replacement. For breath and gums, a half teaspoon dissolved in a glass of water swished for thirty seconds. Hard scrubbing with it wears enamel; light pressure. The squeezable toothpaste recipe on this site builds a real paste around it.

Yes, and it works better than most things in a bottle at the one job, killing the bacteria that make sweat smell. Pat a small pinch onto clean, dry armpits; too much cakes and rubs. Some people's skin reacts to it with redness and itching after a few weeks, because it is alkaline and skin is not; if that happens, cut it with an equal amount of cornstarch or arrowroot, or use it every other day. A spoonful in shoes overnight and a foot soak of three tablespoons in a basin of warm water handle feet.

No. It does not reach a joint, it does not reduce inflammation in arthritis, and drinking it daily to try adds a steady load of sodium that raises blood pressure and works the kidneys. The one joint problem it can help with is gout, and only alongside real treatment: bicarbonate makes the urine less acidic, which helps the kidneys clear uric acid, and a doctor may prescribe it for that reason. On your own, the quarter teaspoon in water for a few days during a flare is the most that makes sense, and the gout itself needs the actual medication.

No, as a habit. A quarter teaspoon is about 300 mg of sodium, most of a day's allowance for someone watching it, and taken daily for weeks it can push the blood alkaline, deplete potassium, raise blood pressure, and in large amounts cause a serious metabolic problem; people have been hospitalized from treating reflux with it for months. It is a short-term remedy for an occasional sour stomach. Heartburn more than twice a week is a reason to find out why.

Yes, on the skin. A paste of baking soda and a little water on a bee sting, a mosquito bite or a patch of poison ivy dries and calms it in a few minutes, and a half cup dissolved in a lukewarm bath takes the itch out of hives, sunburn, chickenpox and a rash for an hour or two. It works by neutralizing the acidic irritants on the skin and drawing a little fluid out of the swelling. Not on broken skin, and a sting with swelling that spreads or any trouble breathing is an emergency, not a paste.