Listerine: “Kills germs that cause bad breath” – Really?


Let’s talk about mouthwash, in particular Listerine.  It sounds like a wonder product, doesn’t it?  A capful in your mouth, swish it around and spit it out and suddenly you’ve rid yourself of a bunch of plaque on your teeth and fixed your gingivitis and given yourself a fresh breath.  Wow!

What have you really put in your mouth?  Alcohol and detergent, a mixture originally inspired by Louis Pasteur’s ideas on microbial infection, the English doctor Joseph Lister demonstrated in 1865 that use of carbolic acid on surgical dressings would significantly reduce rates of post-surgical infection.  Lister’s work in turn inspired St. Louis-based doctor Joseph Lawrence to develop an alcohol-based formula for a surgical antiseptic which included eucalyptol, menthol, methyl salicylate, and thymol.  Lawrence named his antiseptic “Listerine” in honor of Lister.

History of Listerine

Listerine, for instance, was invented in the nineteenth century as a powerful surgical antiseptic. It was later sold, in distilled form, as both a floor cleaner and a cure for gonorrhea.  But it wasn’t a runaway success until the 1920s, when it was pitched as a solution for “chronic halitosis.”   No one truly worried about bad breath as a thing until Listerine’s marketing.

Now, that’s not nearly as bad as what was originally used as mouthwash in Ancient Rome (1 AD) where Romans used to buy bottles of Portuguese urine and use that as a rinse. Importing bottled urine became so popular that the emperor Nero taxed the trade. The ammonia in urine was thought to disinfect mouths and whiten teeth, and urine remained a popular mouthwash ingredient until the 18th century.

The Marketing of Listerine

Marketing has made Listerine a household name.  From 1921 until the mid-1970s, Listerine was also marketed as a preventive and remedy for colds and sore throats.  The Federal Trade Commission said these claims were misleading as Listerine had no efficacy in alleviating or preventing the symptoms of sore throats or colds.  For a short period in 1927 there was a Listerine cigarette marketed.  There were also claims made from the 1930s to the 1950s that applying Listerine to the scalp could prevent “infectious dandruff.”

So, is Listerine Good or Not?

There has been concern that the use of alcohol-containing mouthwash such as Listerine may increase the risk of developing oral cancer. The studies are mixed as to the answer as seven studies have found no connection and yet three studies have found an increased risk.

This is not to say that mouthwash as a whole is bad for you.  Most dentists use a prescription mouthwash known as chlorhexidine (generic name) in their offices to help reduce the number of germs (bacteria) in your mouth or skin.  It is an antiseptic and disinfectant helping with mouth infections, mouth ulcers, and gum disease.  It is used to treat the inflammation known as gingivitis that is caused by the bacteria accumulating, we call plaque.  And remember, plaque loosely adheres to the tooth and gum, which left can harden and become calculus.  Brushing your teeth twice a day (as it takes 12 hours for the plaque to form) does the best job of reducing the plaque in your mouth.

So, spend your money on mouthwash if you have enough to spend on products that really won’t help you a whole lot, or brush your teeth twice a day.


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