What Makes Some Mouthwashes Burn?

| Scott Frey |

Listerine RinseAlcohol usually gets all the blame for the burning sensation you feel from certain mouthwashes, but in fact the burning sensation usually comes from essential oils in the mouth rinse. When I tell people this it usually comes as a big shock, but I am sure that most people have experienced similar burning sensations from cinnamon because of it’s essential oils, so it shouldn’t be all that surprising.
Although alcohol unfortunately does dry out your mouth, which can enhance the burning sensation you feel, alcohol ultimately isn’t the cause of the burning you’re feeling. Interestingly, alcohol isn’t actually added to mouthwashes to fight plaque, in reality it is present as a solvent to keep the other ingredients dissolved in solution.

Why Essential Oils in Mouthwashes Produce a Burning Sensation

The traditional culprit when we think of burning is Listerine. As we have mentioned before on the blog, Listerine relies on a special blend of essential oils to kill bacteria, and while these essential oils are great at fighting plaque they also tend to irritate the insides of our mouths, which is where the burning comes from. Some these essential oils are also responsible for the increased staining sometimes seen with phenolic mouthwashes.
Some of you might be wondering….what about Listerine Zero then, doesn’t it have less alcohol and less burning?
I hear this question a lot, and actually the newer Listerine Zero, which is marketed as a “less intense” mouthwash with no alcohol, gets it’s lower intensity from the fact that it has far less essential oils. It is likely that without the alcohol added as a solvent they could not maintain the same levels of essential oils in their formula.
Additionally, because the concentrations of essential oils in Listerine Zero have been reduced, it cannot be advertised that the rinse is antiseptic like other versions of Listerine (there also will be less phenolics that might cause staining). If you don’t believe, me just look at the bottle, the antiseptic label is not longer present and the essential oils/“Flavors” are way down the list of ingredients indicating lower concentrations.
I hope you all found this post interesting. It should make for great discussion at cocktail parties 😉

About The Author
Scott Frey is a renowned Orthodontist, professional speaker, and founder of the More than Smiles Movement.