Is Mouthwash Bad for You? What Science Says About Its Benefits and Risks

Gargling with mouthwash is a staple in many people’s oral hygiene routines. Many brands promise to “kill 99.9% of germs” that cause bad breath, plaque, and gingivitis. And while there are proven benefits of mouthwash, it also poses risks like dry mouth and irritation. So you might wonder: Is mouthwash bad for you? 

Below, we delve into the pros and cons of using mouthwash to answer that question. 

Is using mouthwash daily bad for you?

Generally, mouthwash is not bad for you when you choose the right type for your needs and use it correctly. In fact, it can be a helpful addition to your oral hygiene routine.

There are two types of mouthwash:

• Therapeutic: These mouthwashes contain active ingredients that help reduce oral health issues like plaque, gingivitis, and cavities. Therapeutic mouthwashes are available over the counter (OTC) or by prescription.

• Cosmetic: Cosmetic mouthwashes temporarily freshen breath. But they don’t have active ingredients to kill bacteria and improve oral health. 

What are the benefits of mouthwash? 

There are several reasons to consider adding a mouth rinse to your oral health routine. Here are some of the top benefits of mouthwash. 

Reduces plaque and gingivitis

Regular brushing and flossing help remove plaque. This sticky film is made of leftover food particles, saliva, and bacteria. The harmful bacteria feed on sugars and starches in the food you eat. And it can lead to tooth decay and gum disease without proper oral hygiene.

Antibacterial mouthwashes can help, too. When mouthwash is used to rinse away food particles and kill bad bacteria, there’s less chance for plaque to build up on your teeth.

A study found that antibacterial mouthwashes reduced plaque and gingivitis, a mild form of gum disease. The researchers noted that prescription mouthwash was more effective than an OTC brand. That’s because some prescription mouthwashes contain chlorhexidine. This powerful antibacterial ingredient may eliminate more germs than OTC rinses. It’s been shown to help mouth sores, oral infections, and bleeding gums.

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Strengthens teeth and reduces cavities

Some mouthwashes include another vital component, fluoride. Consistent use of mouthwash with fluoride helps strengthen enamel, the protective top layer of your teeth. With a stronger protective shield, your teeth are more resistant to cavities.

Freshens breath

The minty flavor of mouthwash alone can freshen your breath. But many mouthwashes also target the root causes of bad breath. For example, rinsing with mouthwash removes food particles that contribute to bad breath.

Certain brands help reduce bacteria that cause odor, resulting in fresher breath. But this benefit is only temporary. Bad breath will return if you don’t properly brush and floss at least twice daily.

What are the side effects of using mouthwash?

Despite its benefits, mouthwash can have side effects, too.

Have you ever noticed a slight tingling or burning sensation when using mouthwash? You’re not alone. Many people think this feeling is a sign that mouthwash is working. But it’s a side effect of ingredients like alcohol. The alcohol is usually a preservative, not an antibacterial agent, in many mouthwashes.

Here’s what you need to know about the disadvantages of mouthwash, especially those with alcohol and other ingredients.

May reduce good oral bacteria 

You want mouthwash to fight bacteria that cause gum disease and tooth decay. But not all bacteria in your mouth are harmful. Some help break down food, making it easier to digest and reducing the likelihood of plaque buildup. This collection of bacteria is part of your oral microbiome. The oral microbiome balances good and bad bacteria to help keep your mouth healthy.

Research suggests that mouthwash can disrupt the oral microbiome. Mouthwash with alcohol, for example, may reduce beneficial and harmful bacteria. Gentler, alcohol-free formulas can still help manage dental diseases and bad breath without some of the unwanted side effects.

Causes dry mouth

Dry mouth (xerostomia) occurs when your salivary glands don’t produce enough saliva to moisten your mouth. It can make it hard to chew, swallow, or taste food. Mouthwash that contains alcohol can cause or worsen dry mouth because the alcohol acts as a drying agent.

Saliva helps wash away cavity-causing food particles from your teeth. With less saliva, the risk of these particles sticking to your teeth increases. If you have dry mouth from a condition or medication, your dentist might recommend an alcohol-free mouthwash with fluoride. Strengthening your teeth with fluoride can help reduce the risk of cavities.

Irritates canker sores

Sodium lauryl sulfate (SLS) is a foaming agent used in some toothpastes and mouthwashes.

If you have canker sores or tend to get them often, SLS could be partially to blame. These small mouth ulcers are usually painful, especially while eating or drinking. Regular use of toothpaste or mouthwash with SLS has been shown to increase inflammation, which may cause or worsen canker sores. The ingredient can also cause dryness or cracking in the corners of your lips.

Stains teeth

Mouthwash with chlorhexidine can stain your teeth, tongue, or fillings, especially with overuse. Although it’s recommended for severe cases of gingivitis, it isn’t for long-term use. Most dentists suggest using chlorhexidine rinses for up to 2 weeks.

How to pick the right mouthwash

There’s no one-size-fits-all choice for mouthwash. So it’s best to choose an option based on your oral health needs. Whether your biggest concern is preventing cavities or bad breath, there’s a mouthwash that can help.

With so many on the market, choosing the best mouthwash can be tricky. Here are a few tips to keep in mind when searching for your next mouthwash:

• Find an alcohol-free option to reduce irritation and side effects, especially if you have dry mouth.

• Select a mouthwash with fluoride to fight cavities.

• Choose a mouthwash with potassium nitrate if you have sensitive teeth.

• Consider rinses containing a sugar alternative called xylitol, which may help prevent cavities.

• Look for labels that include the American Dental Association’s Seal of Acceptance.

• Use prescription mouthwash, such as chlorhexidine, as directed. This will help prevent side effects like staining.

When is mouthwash not recommended?

In some cases, the use of mouthwash is not recommended. For example, children under the age of 6 should not use mouthwash unless advised to by a dentist.

Talk with your dentist before using any mouthwash product if you have:

• Allergies to active ingredients (see the label for more details)

• Active canker sores

• A compromised immune system or are currently undergoing chemotherapy

• A history of alcohol dependence 

Why trust our experts?

Written by:

Zack Youngblood, DMD

Zack Youngblood, DMD, is a dentist who strives to change the general look of dentistry. Before stepping foot in the clinical field, he authored multiple works that helped dental students and dentists find their unique path in dentistry.

Edited by:

Lauren Savage, MA

Lauren Savage, MA, is a health editor at GoodRx, where she focuses on movement, exercise, and healthy aging. She aims to provide readers with the information they need to live healthier, more active lifestyles.

Reviewed by:

Karla Robinson, MD

Karla Robinson, MD, is a medical editor for GoodRx. She is a licensed, board-certified family physician with almost 20 years of experience in health through varied clinical, administrative, and educational roles.

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