The burning sensation while rinsing with Listerine is due to its high alcohol content and to a lesser extent, the minty essential oils as its mouthwash ingredients. Each of these ingredients individually contribute to the burn but the main culprit would be the alcohol.
Table of Contents:
Why does listerine burn so much?
Listerine burns because of the alcohol and four essential oils within it, which make up the core of its active and inactive ingredients.
Active ingredients: Essential oils
Methyl Salicylate (0.060%)
Inactive ingredients: 21.6% alcohol
Listerine contains 21.6% alcohol by volume which is quite acidic.
It is more alcoholic than beer (5%), craft beer, and even wine (12%).
It is less alcoholic than a shot of hard liquor such as vodka or whisky.
Real life evidence of that can be palpable when you compare it to drinking beer and liquor.
It burns more than the beer or wine.
It burns less than having a shot of hard liquor.
It should come as no surprise that it'll feel a little uncomfortable since it is quite alcoholic.
Eucalyptol is extracted from the Eucalyptus plant with reported adverse effects such as:
Sensation of mouth burning
Menthol & Methyl Salicylate
The FDA does caution the use of menthol in that it can cause severe burns in rare cases. Typically these cases involved higher concentrations, 3% menthol and 10% methyl salicylate which are both greater than what is in Listerine.
Nonetheless, the presence of these two essential oils is what gives your mouth that minty tingle. The menthol comes from the mint leaf while the methyl salicylate comes from winter green. Both of which give a slight burn if you've ever had breath mints before.
Thymol which is derived from the thyme plant can burn when it comes into contact with your skin or oral mucosa. In fact, plenty of safety and data sheets list it as one of the hazards.
Hazard class: Skin corrosion or irritation (Category 1). Causes severe skin burns and eye damage (H314).
Listerine alcohol percentage
The alcohol percentage in Listerine may vary from 0% to 26.9% but it depends on which product line you're looking at. In general, we can group together their mouthwashes into three distinct categories based on the amount of alcohol in it.
Listerine (rest off their products)
Listerine Zero Alcohol
How to identify which mouthwash you have
The product naming can be a little bit confusing so we tried to simplify it for you.
Only the Listerine Original comes in a yellow color and it has 26.9% alcohol.
All of the products labeled as "Zero Alcohol" all have 0% alcohol in it.
The rest of their product line all fall under the 21.6% alcohol group.
If you follow the three rules we've provided above, you should be able to figure out which product you've in your hands.
Product with the most alcohol
The Listerine Original has the highest amount of alcohol content at 26.9% which is much greater than all of their other rinses. The rest of their rinses are either 21.6% or 0% ethanol. It is essentially in its own category.
Product with the least alcohol
All of the Listerine products that have the label "Zero Alcohol" in its name do not have any ethanol in it. That also means it'll cause the least amount of burn while rinsing.
Is it supposed to burn?
Listerine is supposed to burn since it was purposefully formulated with alcohol and essential oils. As demonstrated above, all of these five ingredients possess a mildly discomforting characteristic. You'll feel it burn your tongue, cheeks, lips, gums, teeth, and even the palate.
The purpose of it is to eliminate 99.9% of the germs and oral bacteria in your mouth. After all, alcohol is a potent antiseptic is it not? Although despite its intensity, it cannot kill your tooth nerve nor eliminate an infection. However, due to its discomfort while rinsing, we do not recommend using it after an extraction.
Is it harmful?
The burn from rinsing with Listerine is not harmful since the sensation is only transient. It will typically go away on its own within a few minutes of using the product.
However, there has been a lot of concern about whether or not the alcohol content within Listerine could be linked to cancer.
One study found that there was an associated risk of using it on a daily basis with females but not males. However since it wasn't dose dependent, they cannot attribute the casual significance of cancer to daily mouthwash use.
Another study found no evidence of linking mouthwash use to oral cancer.
A third study said that there was potential risk for head and neck cancer.
A fourth study said that it could be an independent risk factor for it.
According to Listerine, there is no evidence of it causing cancer.
Nonetheless, the presence of these reports were enough to scare the general public. Prior to 1991, the formulation for Listerine was actually 26.9% alcohol but they have since reduced it to 21.6% due to concerns. Of course now, they've come out with an alcohol free version.
Note: They've still kept the "original" version of their product with 26.9% alcohol. However, all of the other alcoholic products have been reduced to 21.6%.
Sure, alcohol has been linked to cancer and while the mouthwash does have it, we'd have to say that your weekly happy hour is certainly more harmful than using mouthwash.
When you have an alcoholic drink you're actually ingesting the liquid. That is opposed to rinsing with mouthwash which you do not ingest but spit back out. Clearly, one is more harmful than the other.
What type of alcohol does it use?
The type of alcohol in Listerine is ethyl alcohol (ethanol) C2H5OH but it is USP (pharmacopoeial) grade. That means it was made according to a certain standard and under strict conditions. It was not brewed at home nor was it an off label product.
What does the ethanol do in mouthwash?
The alcohol in Listerine may be an inactive ingredient but it contributes to its efficacy in three ways:
Acts as a solvent and helps to solubilize the rest of the ingredients.
Helps to deliver the active ingredients (essential oils).
Enables the essential oils to penetrate through the bacterial plaque biofilm.
Will it show up on a breathalyzer?
Since Listerine does contain alcohol, it can be detected by a breathalyzer but it won't identify you as being intoxicated.
A study by the Journal of the American Medical Association demonstrated that it poses little risk to your breath test. Apparently, the breath alcohol values will dissipate very quickly after rinsing, thus will not flag you as an alcoholic.
The results of the study:
They tested - Listerine (29.6% alcohol), Scope (18.9% alcohol), and Lavoris (6.0% alcohol) using the Alco-Sensor III intoximeter.
Breath alcohol values decayed exponentially, 2 minutes after rinsing.
After 10 minutes, the values were well below the intoxicated driving level.
In summary, the ethanol can be detected by a breathalyzer but it will rapidly decay within a few minutes. That means if you've brushed and rinsed in the morning prior to getting tested, you shouldn't fail it from your usual oral hygiene morning regime.
How to reduce the burn
The best way to minimize the amount of burn from using Listerine is to switch to their alcohol-free line of products.
They've listened to their consumers and realized that not everyone can tolerate the intense feeling from using their alcohol based mouthwashes. Thus, they formulated a new line of products called Listerine Zero Alcohol, which does not contain any alcohol.
Listerine Zero Alcohol product line:
Cool Mint Zero mouthwash
Total care zero alcohol anticavity fluoride mouthwash
Ultraclean zero alcohol tartar control mouthwash
Zero alcohol mouthwash for fresh breath
How the zero alcohol compares to the alcohol version
We've used the zero alcohol version and we must say that it does feel more pleasant. It certainly burns a lot less than their original product. We do prefer this over their regular one.
It doesn't get rid of the burn completely since it still has the essential oils within it but the amount of burn is significantly less. Therefore if you don't like the alcohol sensation or you have low pain tolerance, perhaps you should switch to the non-alcoholic version.
Vs Other Brands
Our research shows that Listerine's alcohol based rinses have significantly more ethanol in it than its competitors, Crest (Scope) and ACT.
Crest mouthwashes alcohol content:
The Crest Scope Outlast mouthwash has 12.25% alcohol.
The Crest Pro Health Intense Fresh Mint has 15% alcohol.
ACT mouthwashes alcohol content:
The ACT Restoring Mouthwash contains 11% alcohol.
In summary, our darling Listerine especially their ORIGINAL, is the most intense and potent mouth rinse with the highest amount of alcohol in it. They eclipse their competitors by a wide margin.
What if I accidentally swallow it?
If you accidentally swallowed Listerine, the warning label specifically instructs you to contact a poison control center immediately. The most notably adverse effect from doing so would be intoxication which stems from the ethanol in the rinse.
No, please don't try to drink this.
Listerine will burn if you rinse with it because it has alcohol and essential oils. If you can't handle the feeling then you can switch to their zero alcohol line of products. We personally prefer their non-alcoholic one since it feels less intense and is more comfortable to use.
Last but not least, don't forget that using mouthwash is not a replacement for brushing/flossing. You should definitely keep up with your biannual dental check ups to make sure you don't have any dental issues.