Is Mouthwash Bad for You?

Although using mouthwash seems like a simple step in your oral health routine, it turns out that it’s not so straightforward.

Considering factors like alcohol and antiseptic ingredients, oral microbiome disruption, burning or pain from use, and mouth dryness, many people are now uncovering the potential downsides of using mouthwash. 

That’s not to say there are no benefits to mouthwash—there are many—but there are also healthier alternatives to conventional mouthwash that use more natural ingredients and avoid these issues. 

If you’ve been curious whether mouthwash is bad to use daily, this article is for you.

Is Mouthwash Bad for You?

It’s not a cut-and-dry answer to whether mouthwash is good or bad for you, as there are many different types of mouthwash with highly variable ingredients. 

In general, alcohol-based, conventional mouthwashes are not great for you, but more natural, alcohol-free mouthwashes that utilize plant or herb oils can be beneficial for your daily oral hygiene routine. 

Before we dive into the negatives, let’s look at the potential benefits of using mouthwash.

Benefits of Mouthwash

Depending on the type of mouthwash used, using mouthwash regularly has many potential oral health-related benefits, including: 

• Can Kill Harmful Bacteria. Most mouthwashes contain some sort of antimicrobial ingredient, with alcohol being the most common. Other antibacterial or antiseptic ingredients include chlorhexidine (found in therapeutic mouthwashes), cetylpyridinium chloride, and essential oils like eucalyptus, menthol, thymol (oil of thyme), and methyl salicylate (oil of wintergreen).
• May Fight Cavities and Tooth Decay. The most common cavity-fighting mouthwash ingredient is fluoride, which has been shown to reduce the prevalence of cavities and prevent tooth decay. However, there are pros and cons to using fluoride in oral care. Nanohydroxyapatite is an alternative to fluoride that has been studied for its role in reducing cavities without side effects. Alcohol-based mouthwashes may make cavities worse by drying out the mouth, which we’ll see in the next section.
• Freshen Breath. Many essential oils or plants, including menthol, spearmint, and peppermint, are used to keep your breath fresh. Antibacterial ingredients, such as alcohol, cetylpyridinium chloride, and chlorhexidine, freshen breath by killing off bad-breath-causing oral bacteria. Zinc salts have also been found to reduce halitosis (bad breath) when added to oral care products like toothpaste and mouth rinse. 
• Improve Gum Health. Some mouthwashes may improve gum health, including reducing symptoms or the risk of gingivitis or periodontal disease (gum disease). Compounds or ingredients studied for their role in improving gum health include chlorhexidine, cetylpyridinium chloride, stannous chloride, zinc oxide, zinc chloride, licorice, aloe vera, and curcumin.
• Reduce Sensitivity. Potassium citrate, potassium nitrate, and sodium fluoride may lessen tooth sensitivity.
• Whiten Teeth. Hydrogen peroxide is the most commonly used ingredient in tooth whitening mouthwashes.
• Reduce Dry Mouth. Mouthwashes containing xylitol may help with dry mouth symptoms. However, any alcohol-containing mouthwash can worsen dryness.

According to the American Dental Association, mouthwashes can reach areas of your mouth that your toothbrush can’t, which can help to provide an extra layer of protection against tooth decay and gum disease and reduce plaque buildup.  

As untreated gum disease can lead to gum recession and eventual tooth loss, therapeutic mouthwashes can be beneficial to prevent these issues.

Potential Downsides of Mouthwash

While there are plenty of benefits to using mouthwash, there are also some drawbacks to consider—especially when it comes to antibacterial, alcohol-based mouthwashes.

Disrupts the Oral Microbiome

Although they do their job of killing bad bacteria and fighting tooth decay, they also kill good bacteria, which are necessary for our oral microbiome to thrive.

You may think that the oral microbiome solely impacts your mouth, but it actually affects areas all over your body, including cardiovascular and metabolic health.

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 found that people who used antimicrobial mouthwashes twice daily or more had 85% greater rates of hypertension than less frequent mouthwash users.

Although this was a smaller study, ongoing research is actively looking at the correlation between the oral microbiome and its effects on cardiovascular health to verify these results.

Can Cause Mouth Dryness

Alcohol is highly drying, so the use of alcoholic mouthwashes can cause chronic mouth dryness known as xerostomia.

Xerostomia occurs when your salivary glands don’t produce enough saliva to lubricate your tongue. Saliva also helps to prevent cavities, as it supports the process of remineralization in your teeth. 

Therefore, even though many mouthwashes claim to prevent cavities, they can actually make cavities worse by drying out the mouth and reducing natural saliva production.

Can Cause Burning or Pain

Some mouthwashes have high concentrations of alcohol, menthol, or oils from cinnamon, eucalyptus, or cloves. This can cause burning or pain after use—especially in people with sensitive mouths, canker sores, or any oral injury. 

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, natural oils, or chlorhexidine).

Linked to Oral Cancer

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

Does Not Correct Root Cause of Bad Breath

Another potential downside of mouthwash is that it can temporarily mask bad breath, which has a root cause that should be addressed.

Consistently using mouthwash to cover up chronic bad breath may prevent you from finding a permanent solution. 

Not only that, but alcohol-based mouthwashes can make your breath worse.

The minty tingling sensation can cover up bad breath in the short term. However, alcohol in mouthwash dries out the mouth too much, reducing healthy saliva levels needed to manage oral bacteria that lead to fresh breath.

Can Cause Irritation or Sores

Many mouthwashes can irritate the soft tissues of the mouth, especially in people with open sores, canker sores, oral lesions, or ulcers. 

In fact, some mouthwashes can even cause canker sores or mouth ulcers. 

This is because alcohol and other active ingredients like sodium lauryl sulfate (a foaming agent found in many mouthwashes and toothpastes) can impact your cheeks’ protective layers by sloughing off the skin on the inside of your cheeks, potentially causing sores or ulcerations.

The Bottom Line: Is Mouthwash Bad?

Mouthwash is not always bad for you, but many common ingredients in conventional mouthwashes can cause adverse side effects. 

The biggest culprit is alcohol, which leads to mouth dryness, increased risk of cavities, reduced saliva output, mouth irritation, burning, bad breath, microbiome disruption, reduced production of nitric oxide, and potentially even increased oral cancer risk.

Other mouthwashes that contain antiseptic or antibacterial ingredients that wipe out the mouth’s microbiome can have similar adverse effects, while herbal or essential oil-based mouthwashes are much less likely to cause this harm.

Mouthwash FAQs