How to Make and Use a Baking Soda Mouthwash

A baking soda mouthwash is one of the simplest oral rinses you can make at home: dissolve about half a teaspoon of baking soda (sodium bicarbonate) in a cup of warm water, swish for 30 seconds to a minute, and spit. That basic formula neutralizes acids in your mouth, raises salivary pH, and can help with everything from bad breath to sore gums after dental work. The recipe is cheap, the science behind it is surprisingly well-studied, and there are a few practical details worth knowing before you start rinsing.

The Basic Recipe

The standard homemade baking soda mouthwash calls for roughly half a teaspoon (about 2 to 3 grams) of baking soda stirred into 8 ounces (one cup) of warm water. Warm water dissolves the powder faster and more completely than cold water, and you want every grain dissolved before you rinse. Undissolved grit swishing around your mouth can feel unpleasant and may irritate already-sensitive tissue.

Research studies have used concentrations ranging from about 1% to 5% sodium bicarbonate solutions, depending on the condition being treated. For general daily use, the lower end of that range is plenty. If you want a slightly stronger rinse for occasional use, you can bump up to a full teaspoon per cup, but there is no evidence that stronger concentrations deliver proportionally better results for routine oral hygiene. Mix a fresh batch each time you use it, since a pre-mixed solution sitting on the counter can grow bacteria over a day or two.

How to Rinse Effectively

Swish the solution around your entire mouth, pushing it between your teeth and letting it reach the back of your tongue and the insides of your cheeks. Thirty seconds is the minimum for a meaningful effect. If you can tolerate the salty, slightly alkaline taste for a full minute, even better. Spit it all out when you are done. Baking soda is not toxic in the small amounts found in a mouthwash, but swallowing large quantities regularly could cause nausea or, over time, shift your body’s acid-base balance in ways you do not want.

You can use the rinse once or twice a day. Many dentists recommend it after meals, when mouth acids are highest from food and bacterial activity. If you are using it to soothe irritation from a canker sore, a tooth extraction, or orthodontic hardware, rinsing three to four times a day is generally fine for a few days. This rinse does not replace brushing and flossing. Think of it as a complement to your normal routine, not a substitute.

What Baking Soda Actually Does in Your Mouth

The main action is straightforward: baking soda is a mild base, and when you swish it around your mouth, it neutralizes acids produced by oral bacteria. Those acids are what eat away at enamel and create the conditions for cavities. A study examining salivary changes after a sodium bicarbonate rinse found that salivary pH rose significantly, and there was a decrease in colony-forming units of bacteria, particularly Viridans Streptococci and Moraxella species.¹ In plain terms, the rinse made saliva less acidic and reduced some of the bacteria swimming around in it.

This pH shift matters because your mouth spends much of the day in a mildly acidic state. Every time you eat, especially sugary or starchy foods, bacteria ferment the leftovers and produce acid. Your saliva naturally buffers this over time, but a baking soda rinse speeds up the recovery. For people who snack frequently, have dry mouth, or drink acidic beverages throughout the day, that accelerated buffering can be a real advantage.

Helping with Bad Breath

Bad breath, or halitosis, is mostly caused by volatile sulfur compounds produced by bacteria on the tongue and in gum pockets. Baking soda tackles this on two fronts: it raises the pH, which makes the environment less hospitable for many odor-producing bacteria, and it physically flushes debris from surfaces the toothbrush missed.

A clinical comparison found that a baking soda mouthwash was more effective at reducing halitosis than tongue scraping alone. Among those using the baking soda rinse, about a fifth had their bad breath completely eliminated, and the majority of remaining participants dropped to only mild or moderate odor levels. Strong odor was completely eliminated in both the mouthwash and tongue scraper groups.² The takeaway is not that tongue scraping is useless, but that a baking soda rinse tackles odor through chemical means that mechanical scraping alone does not. You can do both for maximum effect.

Protecting Enamel from Acid Erosion

Acid erosion is distinct from cavities, though both involve acid damaging enamel. Erosion comes from direct acid exposure, whether from acidic foods and drinks, gastric reflux, or vomiting. If you have ever been told not to brush your teeth right after throwing up, the reason is that softened enamel is vulnerable to abrasion. A baking soda rinse is the recommended alternative: it neutralizes the acid without the physical scrubbing.

Lab research modeling this exact scenario found that rinsing eroded enamel with a sodium bicarbonate solution produced significantly less surface loss than rinsing with plain water.³ The baking soda controlled enamel surface loss, though it did not change the microhardness of the already-eroded surface. This means it helps prevent further damage but does not reverse damage that has already occurred. For anyone dealing with morning sickness, bulimia recovery, or chronic acid reflux, keeping a pre-mixed cup of baking soda water near the sink is a genuinely useful habit.

Combining Baking Soda with Salt

A common variation adds table salt to the baking soda rinse. The usual recipe is half a teaspoon of baking soda plus half a teaspoon of salt in a cup of warm water. Salt water on its own is a mild antiseptic and can draw fluid out of swollen tissue through osmosis, which is why salt water gargles have been a go-to remedy for sore throats and mouth sores for centuries. Combining the two gives you the acid-neutralizing effect of baking soda plus the anti-inflammatory and mild disinfectant properties of salt.

This combination has been studied specifically in cancer patients undergoing radiation to the head and neck, where painful mouth sores (oral mucositis) are a serious side effect. A trial comparing a salt-soda-bicarbonate mouthwash against benzydamine (a prescription anti-inflammatory rinse) and routine care found that the salt-soda combination produced the greatest reduction in mucositis scores of the three groups.⁴ The fact that a simple salt-and-soda rinse outperformed a pharmaceutical option is striking, though this is one study, and clinical guidelines still vary on the best approach to mucositis.

Use During Cancer Treatment

Oral mucositis, the painful inflammation and ulceration of the mouth lining, affects a large share of cancer patients receiving chemotherapy or radiation. It can make eating, drinking, and even talking agonizing. Baking soda rinses are among the most commonly recommended home remedies in oncology care, partly because they are cheap, nontoxic, and easy for debilitated patients to prepare.

The evidence here is mixed in an interesting way. A trial comparing sodium bicarbonate mouthwash to chlorhexidine (a common antiseptic rinse) in leukemia patients undergoing chemotherapy found that only a quarter of the baking soda group developed ulcerative oral mucositis, compared to nearly two-thirds in the chlorhexidine group. The onset of mucositis was also later in the baking soda group.⁵ Another trial found that both sodium bicarbonate and zinc chloride mouthwashes reduced mucositis severity over three weeks compared to placebo.⁶

However, a systematic review that pooled available studies concluded that the overall evidence supporting baking soda for mucositis management and prevention was limited and of low quality.⁷ This does not mean it does not work. It means the trials so far have been small, variable in design, and hard to compare. In practice, many oncology teams still recommend baking soda rinses because they are safe, inexpensive, and at worst harmless, while the alternative products often cost more and have their own side effects. If you are undergoing cancer treatment, follow your care team’s specific instructions on concentration and frequency.

Dry Mouth and Kidney Disease

People dealing with chronic dry mouth from medications, Sjögren’s syndrome, or other causes sometimes find baking soda rinses helpful. The mechanism involves more than just pH. Gargling with a baking soda solution stimulates nerve pathways involved in saliva production, triggering increased saliva flow through taste and tactile stimulation.⁸ If your mouth feels perpetually parched, the rinse can offer temporary relief by jump-starting your salivary glands.

Chronic kidney disease patients often experience an unpleasant metallic or ammonia-like taste and general mouth discomfort, partly due to elevated urea levels in saliva. A study of kidney disease patients who tried mouthwash solutions of water, salt, sodium bicarbonate, and citric acid found that baking soda provided the greatest improvement in mouth feel and symptom control. About two-thirds of patients found it beneficial, and it was the preferred rinse over the other options.⁹ For a population that deals with chronic oral discomfort and limited treatment options, this is a meaningful finding.

What Baking Soda Mouthwash Will Not Do

One of the most common expectations people bring to baking soda is teeth whitening. Baking soda toothpaste can remove some surface stains through gentle abrasion when you brush with it, but a mouthwash does not involve any scrubbing. You are just swishing liquid around. Research on whitening mouthrinses, including those containing active whitening ingredients, found that none of the tested mouthrinses were more effective than plain water at whitening stained enamel. Only a strong hydrogen peroxide solution (30%, far too concentrated for home use) outperformed water.¹⁰ If whitening is your goal, a baking soda mouthwash is not the tool. Brushing with a baking soda paste or using whitening strips with peroxide will get you further.

Baking soda mouthwash is also not a reliable antifungal treatment. Some people recommend it for oral thrush (candidiasis), and while it can make the oral environment less friendly to Candida by raising pH, it is not a substitute for antifungal medication if you have an active infection. Clinical research has explored sodium bicarbonate rinses in the context of oral Candida in immunocompromised patients, but the results have not been strong enough to position it as a standalone treatment. If you see white patches on your tongue or inner cheeks, see a doctor rather than trying to rinse them away.

Is It Safe for Your Teeth and Dental Work?

A reasonable concern is whether baking soda might scratch or damage enamel, crowns, veneers, or other dental restorations. The good news is that sodium bicarbonate is softer than both enamel and dentin, which gives it an inherently low abrasion profile. A review in the Journal of the American Dental Association noted that baking soda has an intrinsic low-abrasive nature because of its comparatively lower hardness relative to tooth structures.¹¹ That applies even more strongly to a mouthwash, where the baking soda is fully dissolved and there is no mechanical scrubbing involved at all. You are not going to damage restorations by swishing baking soda water around them.

The main safety consideration is taste and tissue tolerance. Some people find the salty, slightly bitter flavor off-putting, and those with mouth sores or raw tissue may experience a brief stinging sensation when they first start rinsing. This usually fades within a few seconds and tends to improve with continued use. If you have a sodium-restricted diet for blood pressure or kidney reasons, keep in mind that a half-teaspoon of baking soda contains a few hundred milligrams of sodium. You are spitting most of it out, but some absorption through oral tissue is possible. Mention it to your doctor if sodium intake is something you carefully track.

Timing It Around Your Other Products

If you use a fluoride toothpaste, you might wonder whether a baking soda rinse immediately afterward would wash away the fluoride. This is a valid concern. Fluoride needs contact time with your enamel to do its job, and rinsing with anything right after brushing, even plain water, reduces that contact. The simplest approach is to separate the two: brush with fluoride toothpaste, wait at least 20 to 30 minutes, then use your baking soda rinse. Alternatively, use the baking soda rinse before brushing or at a different time of day entirely, such as after lunch if you brush morning and night.

If you also use a prescription or antiseptic mouthwash like chlorhexidine, space them apart by at least 30 minutes. Some antiseptic rinses can be inactivated by the alkaline environment baking soda creates. Your dentist or pharmacist can advise on the specific products you use.

A Long History of an Unremarkable Ingredient

Baking soda’s role in oral care is not a modern discovery. Sodium bicarbonate and sodium chloride, either alone or mixed, have been used for tooth cleaning for centuries because they were cheap, widely available, and seemed to work.¹² Early tooth-cleaning powders were often quite abrasive and contained coarse natural ingredients. Baking soda, being relatively soft and water-soluble, was gentler than many alternatives. Its continued presence in commercial toothpastes and professional dental products today is partly tradition and partly because modern research has validated most of the intuitions people had about it. It raises pH, it gently cleans, it is nontoxic, and it is absurdly cheap. Few oral care ingredients have that combination going for them.

What has changed is our understanding of its limits. Earlier generations used baking soda as a cure-all for anything mouth-related. The evidence now tells a more specific story: it is genuinely useful for neutralizing acid, freshening breath, soothing irritated tissue, and complementing other oral hygiene habits. It is not a whitener in rinse form, not a reliable antifungal, and not a proven mucositis preventer despite widespread clinical use. Knowing where it actually helps lets you use it with realistic expectations rather than treating it as a kitchen miracle.