Bicarbonate of soda: facts, health benefits and safe uses

Bicarbonate of soda — also sold as baking soda, and known to chemists as sodium bicarbonate — is one of the hardest-working staples in any pantry. It settles an acidic stomach, scrubs a burnt pot, deodorises a fridge and, in serious sport, even earns a place in athletes' race-day routines. It's also surrounded by more myths than almost any other household product. This guide covers what it genuinely does well, what the evidence says, and how to use it safely.

What bicarbonate of soda is

Sodium bicarbonate (NaHCO₃) is a mildly alkaline salt — dissolved in water it sits at a pH of about 8.3, on the opposite side of neutral to acids like lemon juice (pH ~3). That simple chemistry explains almost everything it does: when bicarbonate of soda meets an acid, it neutralises it, releasing carbon dioxide — the same fizz that makes cakes rise. People have used it for centuries; the ancient Egyptians cleaned with natron, a naturally occurring form of the same family of salts.

One practical note: bicarbonate of soda and baking soda are the same thing. Baking powder is different — it's bicarb pre-mixed with a dry acid for baking, and not what you want for the uses below.

The pH story — what's true and what's overblown

You'll read online that bicarb "alkalises the body" and that disease can't survive in an alkaline environment. That second part is a myth worth clearing up: your body tightly regulates blood pH within a narrow range regardless of what you eat or drink, and no food or supplement changes that. What bicarb can change, briefly, is the pH where it actually goes — your stomach contents, your urine, or the water in a bath. Every genuine use below works through that local, temporary effect, not through "alkalising" your whole system.

Settling occasional heartburn and indigestion

This is bicarb's classic use, and the chemistry is straightforward: it neutralises excess stomach acid on contact, which is why it has been used as a home antacid for generations. The fizzing reaction also encourages burping, which can ease that over-full, gassy feeling after a big meal. Dissolve a small amount (about a quarter teaspoon) completely in a glass of water. It's a short-term measure for occasional discomfort — if you need an antacid most days, that's a conversation for your doctor, not a bigger box of bicarb.

Wondering what else helps? We've compared bicarb with other options in our guide to the best drinks for acid reflux relief.

Exercise performance — the use with the strongest science

Surprisingly, the best-researched benefit of bicarbonate of soda has nothing to do with digestion. "Soda loading" — taking bicarb before short, high-intensity exercise — is a recognised ergogenic aid, because the extra buffering capacity helps neutralise the acid build-up that makes muscles burn during hard efforts. We've covered how it works, who it helps and how athletes actually use it in our full guide to bicarbonate of soda and athletic performance.

Kidney health — interesting research, not a home remedy

A study published in the Journal of the American Society of Nephrology found that sodium bicarbonate supplementation slowed the decline of kidney function in patients with chronic kidney disease. It's genuinely promising research — but it describes a medical treatment given under specialist supervision to people with an existing diagnosis. If you have kidney concerns, bicarb is something to discuss with your doctor, not to self-prescribe; in fact, kidney disease is one of the conditions where you should avoid taking bicarb on your own (see the safety section below).

Teeth, skin and bath uses

Bicarb's mild abrasiveness and odour-neutralising chemistry make it a favourite in the bathroom cabinet:

Oral care. A little bicarb on a toothbrush is a time-honoured way to help lift surface stains, and a half-teaspoon swished in water makes a simple freshening rinse.

Skin soothing. A cool bicarb paste (three parts bicarb to one part water) is a traditional way to calm the itch of insect bites, and a lukewarm bicarb bath can feel soothing on sun-exposed or irritated skin. It works at the surface — neutralising irritants and drawing heat — and washes clean away.

Deodorant and exfoliation. Bicarb absorbs odours rather than masking them, which is why it features in so many natural deodorant and scrub recipes. For step-by-step versions, see our DIY beauty recipes with bicarbonate of soda.

Around the home

The same chemistry cleans: an open tub deodorises a fridge, a sprinkle scours pots without scratching, and a bicarb soak helps lift odours from chopping boards and flasks. A paste even eases splinters out — soften the skin with a bicarb-and-water paste under a plaster and the splinter often works its way to the surface.

How to use bicarb safely

Bicarb is safe in small, occasional amounts for most healthy adults — but "natural" doesn't mean "unlimited". Keep these rules:

Dissolve it completely in water and stick to small amounts (a quarter teaspoon at a time is plenty for digestive use). Remember it's a sodium salt — if you're watching your salt intake, that counts. Don't take it within two hours of prescription medicines, as it can affect how they're absorbed. And skip internal use altogether if you have kidney or liver disease or high blood pressure, are pregnant or nursing, or you're giving it to a child under five — for all of those, talk to a doctor or pharmacist first. Bicarbonate of soda is a household helper, not a treatment for any medical condition.

Frequently asked questions

Is bicarbonate of soda the same as baking soda? Yes — two names for pure sodium bicarbonate. Baking powder is different (bicarb plus a dry acid) and isn't suitable for the uses in this guide.

Can bicarb "alkalise" my body? No — your blood pH is tightly regulated and doesn't shift with foods or supplements. Bicarb temporarily changes the pH where it's applied: stomach, urine or bathwater. That's enough for every genuine use it has.

What's the right bicarbonate of soda dosage? For occasional digestive use, about a quarter of a teaspoon dissolved completely in a glass of water is plenty — more isn't better. There's no "daily dose for health": if you have any of the conditions in the safety section above, or you're on prescription medicines, check with a doctor or pharmacist before taking it at all.

What's the difference between food-grade and cleaning-grade bicarb? Purity. Anything you swallow or brush with should be food-grade or better — pharmaceutical-grade is the highest purity, made for consistent, food-safe use.

Can I take bicarb every day? It's best kept for occasional use. If you feel you need it daily — for digestion or anything else — that's a sign to check in with your doctor rather than to keep topping up.

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