Mouthwash, also called “oral rinse” or “mouth rinse,” typically contains antibacterial ingredients to clean between your teeth, as well as other ingredients that give it a flavor. Some types of mouthwash contain alcohol as an inactive ingredient, while others are alcohol-free.
For some people, mouthwash can have some unpleasant side effects. These side effects may outweigh the benefits of using an over-the-counter oral rinse as part of your everyday routine. Other people have expressed concerns over some of the chemical dyes and flavors in certain brands of mouthwash.
That being said, mouthwash isn’t bad for you, per se. Let’s take a look at the side effects of mouthwash and what you should know about using it safely.
Alcohol is used as a preservative ingredient and as a carrier for the other active ingredients in mouthwash, not as an antiseptic ingredient.
Not every person will experience all of the following side effects of mouthwash, and certain formulas are more likely to cause more or fewer side effects.
May cause or irritate canker sores
An ingredient called sodium lauryl sulfate (SLS) is used in some toothpaste and oral rinses to create a “foaming” action in your mouth.
If you’re prone to developing canker sores, using a mouth rinse (or any oral product) that contains SLS might cause an outbreak of sores or make them worse. People who are currently undergoing chemotherapy treatment may also find that to be the case.
If you don’t have these sensitivities or concerns, it’s likely that you won’t experience this side effect.
May cause dry mouth
Xerostomia, also known as dry mouth, refers to a condition where your salivary glands don’t produce enough saliva to keep your tongue lubricated and to help prevent cavities.
An oral rinse that contains fluoride may actually be recommended if you have dry mouth, according to the American Dental Association. However, a mouthwash that contains alcohol may actually make symptoms of dry mouth worse.
May cause burning or pain when you use it
Some people enjoy the feeling of a tingling sensation when they use mouthwash that contains alcohol. But for others, the feeling can be more like a burning pain.
Some mouthwashes contain up to 25 percent alcohol, which makes this sensation more powerful.
Some side effects of mouthwash aren’t related to whether there is alcohol in the formula.
May remove your healthy oral microbiome
Any type of mouthwash, whether alcohol-free or containing alcohol, may kill off a high number of bacteria in your mouth.
Some bacteria in your mouth can lead to cavities and bad breath, but other bacteria are actually part of what’s called your oral microbiome, which helps break down your food and maintains healthy teeth and gums.
Killing off all of the bacteria in your mouth on a regular basis isn’t recommended, so gentler antiseptic formulas can be a healthier choice.
May cause teeth staining
The most common side effect of using mouthwash, according to a
Mouthwash that contains an ingredient called chlorhexidine (CHX), which is only is available by prescription, is
Mouthwashes that contain bright dyes are more likely to cause staining than dye-free mouthwash.
May be linked with increased cancer risk
Mouthwash may also contain synthetic ingredients that have been linked to an increased risk of certain cancers.
A lot more research is needed to understand whether this link is real and, if so, which ingredients cause the risk to increase.
There’s such a thing as using mouthwash too often.
Most nonprescription mouthwashes advise you to use the product twice per day, along with brushing and flossing. Some people like to use mouthwash more than that, using it to freshen breath or get that “clean mouth” feeling in between meals.
You should cut back or discontinue mouthwash use if you experience any of the following symptoms:
- persistent or inflamed canker sores
- bleeding gums when you use your mouthwash
- symptoms of dry mouth
- pain or sensitivity when you brush your teeth after using mouthwash
- teeth staining
Children under the age of 6 shouldn’t use mouthwash, and kids over 6 should be supervised whenever they use mouthwash, according to the American Dental Association.
If you have sores in your mouth, have a compromised immune system, or you’re currently undergoing chemotherapy, you might want to avoid using mouthwash.
If you have had an allergic reaction to any type of mouthwash ingredient (such as with flomenthol, xylitol, or SLS), check labels carefully to make sure that you’re not using a product that may cause irritation.
Mouthwash does have some health benefits. However, according to the American Dental Association, you should look for vetted formulas that have the organization’s seal of approval.
Over-the-counter mouthwash can:
- freshen breath and treat halitosis
- reduce your risk of gingivitis (gum disease)
- reduce plaque buildup to help prevent cavities
- make teeth look visibly whiter
That said, no mouthwash formula is a substitute for regular brushing and flossing twice per day, which is the foundation of good dental hygiene.
There are alternatives to using mouthwash. Flossing and brushing twice per day have more proven benefits and fewer possible side effects.
Additionally, you may want to ask a dentist about prescription oral rinses. These rinses have higher levels of certain active ingredients, making them effective for temporary use for the treatment of certain oral conditions. You can use prescription oral rinses for:
- symptoms of dry mouth
- gum disease prevention
- pain relief for mouth ulcers/canker sores
- preventing infection and dry socket following a dental extraction or other oral surgery
Mouthwash can have some unpleasant side effects. Some of these side effects are only caused by mouthwash formulas that contain alcohol or certain other ingredients.
But on the whole, mouthwash isn’t bad for your health or harmful for you to use. You can use mouthwash as a part of a healthy oral hygiene routine, or you can opt out of using it. It’s really just a matter of personal preference.
If you have chronic bad breath, are concerned about plaque buildup and gum disease, or are generally curious about improving your dental health, you should speak with your dentist.