Why Does Mouthwash Burn?


If you’ve ever seen a mouthwash commercial, the happy people with blindingly white teeth tend to proclaim that the tingling feeling post-mouthwash is refreshing and cleansing.

But for many, that “tingle” is less pleasant, causing a painful stinging or burning sensation.

Although it’s commonly thought that a burning feeling means that mouthwash is working, that’s not entirely true.

Let’s dive into why certain mouthwashes burn, which ingredients to watch out for, and our top recommendations for alcohol-free mouthwashes that won’t leave your tongue feeling like it’s on fire.

Why Does Mouthwash Burn? 5 Top Causes

The most common reason why mouthwash burns when you use it is due to alcohol.

Many mouthwashes include alcohol to kill off oral bacteria and fight bad breath—but it also can cause painful burning sensations, similar to when you take a shot of hard liquor or pour alcohol on a cut. This is especially true if you have a sensitive mouth, oral infections, or sores.

Another cause of burning in mouthwashes is menthol—a compound found naturally in spearmint and peppermint oil. 

While menthol often provides that fresh and minty flavor, some mouthwashes go overboard, leading to feelings of stinging. Plus, some people are extremely sensitive to menthol, causing severe burning sensations after use. 

Similarly, essential oils like those derived from eucalyptus, tea tree, lavender, cloves (eugenol), or thyme oil (thymol) can also cause a burning mouth, especially in sensitive people.

Essential oils like these are deemed healthier alternatives to alcohol, as they also provide antimicrobial and bacteria-killing properties. But unlike alcohol, they do not seem to kill off beneficial bacteria in the mouth in the same way. 

For more details and research on this topic, jump to the section “Should You Use Alcohol-Based or Antibacterial Mouthwash?” 

A fourth mouthwash ingredient that can cause burning sensations is hydrogen peroxide, which is often included in teeth-whitening mouthwashes.

While the hydrogen peroxide concentration in such mouthwashes is usually low, it can still trigger a burning sensation in some people.

Lastly, any type of mouthwash may cause burning if you have dental issues, including cold sores, canker sores, bleeding gums, gum disease, mouth ulcers, or any type of open infection or irritation. In this case, you’ll likely notice more pain and burning if you use a mouthwash containing alcohol, menthol, or oils like thyme, tea tree, and eucalyptus.

Why Does Mouthwash Burn? 5 Top Causes

Mouthwashes That Don’t Burn

If you have dental health problems, you may want to avoid mouthwashes altogether because they may irritate your issue—regardless of whether they contain alcohol.

Instead, a quick rinse with water after meals combined with gentle brushing and flossing can help prevent tooth decay, remove food particles, improve gum health, and control bad breath.

For people without active gum or oral infections or issues, there are many alcohol-free formulas that do not burn. As alcohol is not a necessary ingredient in mouthwash—and likely detrimental—feel free to use an alcohol-free mouthwash. 

However, some oils and other natural ingredients (like menthol) still have the potential to burn if the concentration is too high. Menthol, spearmint, and peppermint are not necessary ingredients in mouthwash, either—but they do provide that sought-after fresh-and-minty feeling. 

If you’re sensitive to menthol, look for menthol-free, mint-free, or flavorless mouthwashes like CloSYS Ultra Sensitive Mouthwash.

Overall, people tend to experience the worst burning from alcohol-based mouthwashes. Some nonalcoholic mouthwashes that are lighter on menthol or essential oils and likely won’t burn include:

If you want to go the DIY route, you can also try a salt rinse—mixing salt with warm water—as a simple mouthwash that won’t burn.

Interestingly, studies have shown that salt rinses can reduce plaque buildup and inhibit certain oral bacteria as effectively as chlorhexidine (a common therapeutic mouthwash for fighting gingivitis or gum disease).

Should You Use Alcohol-Based or Antibacterial Mouthwash?

There are some downsides to using antibacterial or antiseptic mouthwashes.

While many dentists recommend antibacterial rinses, emerging research suggests that mouthwashes that kill bacteria are not as beneficial as we once thought.

Unfortunately, the vast majority of mouthwashes use some sort of antibacterial agent. Although they do their job of killing harmful bacteria and fighting tooth decay, they also kill healthy bacteria, which are necessary for our oral microbiome to thrive.

Killing off all the bacteria in your mouth can deplete oral nitrate-reducing bacteria. This leads to reduced nitric oxide availability—a vasodilating compound linked to better heart, vascular, respiratory, and immune health. 

In a 2020 study, researchers examined antibacterial mouthwash use and blood pressure rates over three years.

One notable finding was that people who used antimicrobial mouthwashes twice per day or more had 85% greater rates of hypertension (high blood pressure) than less frequent mouthwash users. 

Alcohol-based mouthwashes are the biggest culprit here. Research shows that essential oil-based mouthwashes do not have the same capacity for killing off nitrate-reducing bacteria

However, they do show effectiveness in killing oral pathogenic bacteria—especially peppermint, tea tree, and thyme oil.

Some studies have also suggested that alcohol-based mouthwashes can negatively affect soft tissue in the mouth, which may increase the risk of oral, head, and neck cancers.

How to Use Mouthwash Most Effectively

Mouthwash is never a replacement for your regular oral hygiene routine of daily brushing and flossing, but it can help control bad breath, fight plaque buildup, and support gum health. 

That said, mouthwash is also not necessary for oral hygiene—proper and regular brushing and flossing can suffice. 

For most people, here is a typical oral health routine incorporating mouthwash: 

  • Brushing: Brush your teeth using a toothbrush with soft bristles and toothpaste. (Whether or not you use fluoride products is up to you.) 
  • Flossing: Floss your teeth thoroughly with regular floss or dental floss picks. 
  • Mouthwash: If you use fluoride-based toothpaste, wait 30 minutes before using mouthwash. Otherwise, use your mouth rinse after flossing. Most mouthwashes come with a cap with measurements on the inside. Pour out as much as the bottle instructs—typically between 3 and 5 teaspoons. 
  • Rinsing and spitting: Swish the mouthwash around your mouth for 30 seconds, then spit it out. Never swallow mouthwash, and do not rinse your mouth with water afterward. 

Regarding timing, various health organizations have differing recommendations about when to use mouthwash.

Following the American Dental Association’s guidelines, you can use mouthwash before or after brushing based on your preferences.

If you have specific questions about your oral health or particular dental situation, see your dentist and ask them to tailor a plan for you.

Why Does Mouthwash Burn FAQs

Does Burning Mouthwash Mean It’s Working?

When mouthwash burns, that does not necessarily mean that it’s working. The most common ingredients that burn in mouthwash are alcohol and menthol (mint), which can kill off bacteria and freshen your breath. 

However, they are not required for a mouthwash to perform these actions, nor are they always recommended (especially alcohol). Although you may think you need to “feel the burn” in order for mouthwash to be effective, that is not the case. In fact, a burning sensation from mouthwash often means that it is too irritating for you and could cause more harm than good. 

Mouthwash should not hurt you—a pleasant tingling may occur from menthol, mint-derived ingredients, or some essential oils (like cloves or tea tree), but a heavy alcohol-based mouthwash that causes a burning sensation is not recommended.

Is Alcohol-Free Mouthwash Less Effective?

While alcohol is effective at killing bacteria, so are many other compounds and active ingredients, including menthol, essential oils, and therapeutic ingredients like chlorhexidine (all of which also can cause a burning sensation). 

Research from 2021 found that both nonalcoholic and alcoholic oral rinses were equally effective in controlling plaque and gingivitis. The alcohol-containing mouthwash also induced more significant cell damage when compared with the nonalcoholic mouth rinse. Plus, essential oil-based mouthwashes seem to selectively kill off pathogenic bacteria while not harming healthy, nitrate-reducing bacteria. Therefore, the answer is no; alcohol-free mouthwash is not less effective.

Is Mouthwash Supposed to Burn?

While it’s not unusual for your mouthwash to burn, for best oral health, it shouldn’t. Some mouthwashes have high concentrations of alcohol, menthol, or essential oils, which are common burn-inducing ingredients.

Therapeutic mouthwashes (like those used to treat a certain condition, like gum disease) may burn more than cosmetic mouth rinses (which are used to freshen breath)—but this is not always the case, as many cosmetic mouthwashes use alcohol.

However, a mouthwash that causes a burning sensation does not necessarily mean it’s working—but it does mean it has an ingredient that could be irritating you (typically alcohol, but it could also be menthol, essential oils, or chlorhexidine). Plus, these ingredients (especially alcohol) also kill off bacteria, which we’ve learned is not always a good thing when it comes to the oral microbiome. 

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