Baking soda is not inherently dangerous in small amounts, but using it as a home remedy, whether swallowed for heartburn or applied to skin, carries real risks that most people underestimate. A single teaspoon contains roughly 1,260 milligrams of sodium, which is more than half the recommended daily limit for most adults. That alone makes casual use problematic, but the dangers go well beyond sodium.
The Sodium Problem
Each teaspoon of baking soda delivers about 59 milliequivalents of sodium, equivalent to roughly 1,260 mg. The American Heart Association recommends no more than 2,300 mg of sodium per day, with an ideal limit of 1,500 mg for most adults. So a single teaspoon of baking soda dissolved in water gets you most of the way to your daily cap before you’ve eaten anything. People who take it multiple times a day for heartburn can easily consume several times the safe sodium limit without realizing it.
For anyone with high blood pressure, heart failure, or kidney disease, this extra sodium forces the body to retain fluid. That raises blood pressure and makes the heart work harder to pump the increased volume. Even in otherwise healthy people, chronic high sodium intake contributes to cardiovascular strain over time.
How It Disrupts Blood Chemistry
Baking soda is sodium bicarbonate, an alkaline compound. When you swallow it, it raises the pH of your blood and body fluids. In small, occasional doses, your kidneys correct this shift easily. But with larger or repeated doses, the result is a condition called metabolic alkalosis, where the blood becomes too alkaline for normal cell function.
The symptoms of metabolic alkalosis are highly variable. Mild cases cause nausea, muscle twitching, and confusion. Severe cases, documented in emergency medicine case reports, have triggered seizures, dangerous heart rhythm changes, and even cardiac arrest. Two patients reported in the Journal of Emergency Medicine developed severe metabolic alkalosis from unsuspected antacid overuse, illustrating how easy it is to cross the line without intending to.
Excess bicarbonate also pulls potassium out of the bloodstream and into cells, dropping your blood potassium levels. This happens through a direct ionic shift, not just through the kidneys. Low potassium causes muscle weakness, cramping, and in serious cases, heart rhythm disturbances. The combination of alkalosis and low potassium is particularly dangerous because both independently affect the heart.
Stomach Rupture Is Rare but Real
When baking soda hits stomach acid, it produces carbon dioxide gas rapidly. In a normal, mostly empty stomach, this causes bloating and burping. But if the stomach is already full or distended, the sudden gas expansion can be dangerous. The pressure inside the stomach can exceed the strength of the stomach wall, particularly along the lesser curvature, which is the weakest point due to fewer muscular folds.
For rupture to happen, two things generally need to coincide: the stomach must already be stretched, and the normal venting mechanisms (belching or emptying into the intestine) must be blocked. This is why cases of baking soda-related stomach rupture tend to involve people who have eaten very large meals. Cadaver experiments have demonstrated that adding sodium bicarbonate to 2 to 3 liters of dilute acid in the stomach reliably causes rupture. While this scenario is extreme, it highlights why drinking baking soda on a very full stomach is genuinely risky.
It Can Change How Your Medications Work
Because baking soda alters the pH of both your gut and your urine, it interferes with how your body absorbs and eliminates a wide range of medications. Certain antibiotics, including common ones like doxycycline and levofloxacin, are significantly less absorbed when taken alongside baking soda. The pH change in the gut alters the chemical structure of these drugs before they can enter the bloodstream, making them less effective at fighting infection.
Anti-inflammatory drugs and some extended-release formulations are similarly affected, with reduced absorption that can make them less effective. On the flip side, baking soda increases blood levels of certain stimulant medications by making the urine more alkaline, which causes the kidneys to reabsorb more of the drug instead of filtering it out. This means taking baking soda alongside these medications could lead to unexpectedly high drug levels and increased side effects.
Effects on Skin
Baking soda has a pH of about 9, while healthy skin sits between 4.5 and 5.5. That protective acidity, sometimes called the acid mantle, is what keeps moisture locked in and harmful bacteria out. Applying baking soda to the face or body pushes skin pH far above its normal range, stripping natural oils and weakening the barrier that protects against infection and breakouts.
The result is dryness, irritation, and increased sensitivity. Over time, repeated use can leave skin more prone to redness and reactive to other products. Despite its popularity in DIY skincare, baking soda is too alkaline to use safely as a face wash or scrub on a regular basis.
Teeth: Less Harmful Than You’d Think
Interestingly, baking soda is one of the least abrasive substances used in toothpaste. Its Relative Dentin Abrasivity score is just 7, which is extremely low compared to most commercial toothpastes (which range from 30 to over 200). So concerns about baking soda destroying tooth enamel are largely overblown. The real issue with using plain baking soda on teeth is that it lacks fluoride and doesn’t offer the cavity protection of actual toothpaste. It can help remove surface stains, but it’s not a replacement for a complete oral care product.
Who Faces the Greatest Risk
People with kidney disease face the highest danger from baking soda because their kidneys cannot efficiently clear the excess sodium and bicarbonate. The sodium builds up, worsening fluid retention, while the bicarbonate accumulates and shifts blood chemistry toward alkalosis. For someone with compromised kidney function, even moderate doses can cause serious electrolyte imbalances.
People with heart failure are similarly vulnerable. The sodium load increases fluid volume, which strains an already weakened heart. And anyone taking prescription medications should be cautious, since the pH changes caused by baking soda can unpredictably raise or lower drug levels in the blood.
Children are another high-risk group. There is not enough reliable safety data on oral sodium bicarbonate use in children to establish safe limits. Their smaller bodies and developing kidneys make them more susceptible to electrolyte shifts, so baking soda should not be given to children as a home remedy.
The Dose Makes the Difference
Baking soda is considered safe for short-term use in adults at controlled doses, typically in the range of a half teaspoon dissolved in water, taken no more than every two hours and not for longer than two weeks. Going beyond that, whether in dose or duration, is where the risks climb steeply. The problem is that many people treat it as a harmless pantry item and don’t measure carefully, don’t limit how often they take it, or use it daily for weeks or months. That casual approach is what turns a low-risk antacid into a genuine health hazard.