Why Does Mouthwash Burn?

Written by Dr. Gibbz

November 09, 2022

Medically Reviewed

By Dr. James Younan, DDS

So you just left the dentist office and your dentist told you that you need to work on your oral hygiene. Oral hygiene? What is that? Oral hygiene is exactly what it sounds like, the hygiene of your mouth. Basically, your dentist is telling you that you need to floss, rinse, and brush more often.

In my experiences, I find that patients brush their teeth more often than they floss. However, patients will use mouthwash almost twice as often as they brush their teeth. Why? Because it is more convenient! You just grab a bottle, rinse and boom! You instantly fee like your mouth is clean. WRONG! 

What is the true purpose of mouthwash?

Mouthwash should never be used as a substitute for flossing and brushing. I’m going to break down why some mouthwash burns, the true purpose of mouthwash, and my recommendations on what mouthwash to use. Let’s go!

Snow Whitening Mouthwash

Alcohol free mouthwash vs. alcohol mouthwash

I am sure you are all aware of the many different brands of mouthwashes that are out there. However, they do have some things in common and typically it written out boldly to grab your attention. Words like “ALCOHOL FREE” or “ZERO ALCOHOL”. When you see this on a mouthwash, you automatically know that this mouthwash will not give you that burning sensation when you rinse with it. Some of you love to use alcohol free mouthwashes and some of you don’t. Why? 

Why mouthwash burns:

That burning sensation that leaves your mouth tingly is caused by... well you guessed it right, alcohol. So why do these mouthwashes have alcohol in them and why do they burn? Alcohol is used as a way to deliver some of the key features of mouthwashes such as getting rid of the bacteria that causes bad breath, essential oils that help to break down and prevent plaque build-up, fluoride to help make your teeth more acid resistant and help to prevent cavities, peroxide to help whiten your teeth….. the lists goes on and on. 

With COVID-19, many people became very familiar with hand sanitizers. Well, guess what, the main ingredient in hand sanitizer is Alcohol and it helps to do what?… Alcohol kills bacteria. In mouthwashes, alcohol serves the same purpose, to kill the bacteria in your mouth.

Is alcohol mouthwash good for your oral health?

This sounds like a good idea right? Well, yes and no. Here’s why. 

Alcohol in your mouth means the bacteria get killed off, but what type of bacteria is being wiped out? In your mouth you have good bacteria and bad bacteria. There is a balance between the two. Cavities are formed when there are more bad bacteria than there are good. When you don’t floss and brush your teeth, the bad bacteria builds up much faster than the good bacteria does and now there is an imbalance.

The more bad bacteria you have, the more acidic your mouth becomes and the acid is what breaks down your teeth to cause a cavitation “cavity” on your teeth. Anyways, that will be discussed in a later post. Back to alcohol and mouthwashes. Alcohol in mouthwashes don’t just wipe out the bad bacteria, they remove the good ones also. This can cause irritated mouth tissue if you consistently use a mouthwash containing alcohol. 

Alcohol also dries your mouth out. For people who naturally have a dry mouth or have a condition called xerostomia, alcohol in mouthwash can make your condition worse. In this case, you can use mouthwash and it can actually increases the chances of you getting cavities!

How? Because when your mouth is dry, there is less saliva to keep the bacteria moving.

Snow Whitening Toothpaste

This means that the bacteria can stay on your teeth longer. Also, your saliva has calcium and phosphate in it which helps to remineralize the enamel of your teeth. Essentially, it helps to counteract the acid that the bad bacteria makes to help prevent cavities. With dry mouth, the bacteria is staying on your teeth longer and producing acid, there is less phosphate and calcium being delivered to the teeth to help counteract the acid, theoretically increasing your chances of having cavities. 

Now, I am not saying that by using an alcohol-containing mouthwash, you will get cavities. What I’m saying is, talk to your dentist about your oral health and see what type of mouthwash is best for you. If you have dry mouth, be careful using a mouthwash with alcohol in it as it can make your condition worse.  

For some people, the burn is a motivating factor. It makes you feel like you are getting a better clean with the alcohol burn and minty flavor. For you, alcohol mouthwashes are a good thing because it means you will consistently use it and get the benefits of your specific mouth rinses such as whitening, fresh breath, and fluoride. 

Two types of mouthwashes: cosmetic and therapeutic

Cosmetic mouthwash

Cosmetic mouthwashes are used to help improve the way your teeth look, aka whitening, and they also help with bad breath.

Therapeutic mouthwash

Therapeutic mouthwashes are those that address an issue, such as bleeding gums, high levels of bacteria in the mouth, kill bacteria, and deliver fluoride.

Majority of these mouthwashes can be purchased over the counter. Some mouthwashes are prescription based which means you will need a prescription from your dentist.

Which mouthwash is the best for you? Ask your dentist! 

For my patients who don’t suffer from dry mouth (xerostomia), I recommend using an alcohol containing mouthwash. There are also alcohol free options that cause less mouthwash burn. If you have bad breath, the best mouthwash, in my experience, is Therabreath Mouthwash. For those of you who do not like using fluoride products, there are also mouthwashes without fluoride.

Just look at the back of the bottle in the “Active Ingredients” section and this will tell you if the mouthwash contains fluoride.

A quick side note, fluoride is amazing and helps to drastically prevent cavities. However, I know there are many out there who do not like using fluoride containing products and for those people, I would recommend you look into products that have Nano Hydroxyapatite (nHAP). It is a natural substance that helps to make up your enamel and the bones in your body. It is safe to use but as always, do your own research, as you have done with fluoride, and thank me later. 

LED Electric Toothbrush


So to sum it all up, mouthwashes are great and have many benefits. Some come with hydrogen peroxide to whiten teeth, essential oils for a pleasant smell and to soothe gums, and ingredients to kill germs. However, you should never replace brushing and flossing with mouth rinse alone.

The proper oral hygiene routine is what I like to call FRBR: Floss - Rinse - Brush - Repeat. If you have dry mouth or a condition called Xerostomia, use a mouthwash without Alcohol in it. If you do not have dry mouth and don’t mind a little stinging sensation, use a mouthwash with alcohol in it. Each mouthwash has its added benefits to help improve your oral health and prevent tooth decay. Some mouthwashes work better than others do but that is always dependent on the person using it. As I always say, talk to your dentist to see which mouthwash is best for you.  

For more dental education content, check out my YouTube channel and follow me on Instagram (@Dr_Gibbz). 

- Dr. Gibbz (Public Health Dentist)

Disclaimer: This article is for educational purposes only and there is no doctor/patient relationship being established by reading this article. Always consult with your dentist or primary care provider. This article is not intended to offer medical or dental advice to anyone, it is not intended to diagnose any medical or dental conditions that you may have. There are no warranties and/or guarantees being made with the information being presented in this article.