Mouthwash: Does It Really Work?

How a centuries-long battle with halitosis led to a surprisingly effective weapon in our oral care arsenal.


Head down to your local grocery store, and chances are you'll find rows upon rows of mouthwash products, all of them making seemingly impossible claims about what they can do. Some of them take a page from the suntan lotion industry by offering "12-hour protection" from plaque and bacteria. Others say they'll make your teeth 50 percent stronger. Leaving aside all the marketing-speak, does using mouthwash actually make much of a difference? Or is our faith in what's become a $689 million-a-year industry simply the result of received wisdom?

Turns out it's a little bit of both. Our obsession with fresh breath has a history stretching back centuries, if not millennia. The ancient Chinese were known to rinse their mouths out using children's urine as a way to keep the gums clean. Ancient Greek scholars like Hippocrates and Pythagoras suggested solutions of salt, alum, and vinegar to maintain fresh breath.

In some places, getting rid of halitosis meant chewing natural substances instead of rinsing:

The Bible (Genesis) mentions labdanum (mastic), a resin that has been used in Mediterranean countries for breath freshening for thousands of years; it may be the original chewing gum. Other folk cures include parsley (Italy), cloves (Iraq), guava peels (Thailand), and eggshells (China). The Talmud suggests peppercorns.

With the Renaissance, people graduated to alcohol -- rinsing with wine or beer. Five hundred years later, alcohol remains a major ingredient in some of the leading brands of mouthwash. The original, gold-colored Listerine is reportedly 26.9 percent alcohol. And while alcohol-based rinses have been tentatively linked to higher rates of oral cancer, manufacturers aren't making it up when they say their products have been clinically proven.

Since the mid-1980s, six-month trials have repeatedly shown that using mouthwash actually has an appreciable effect on plaque and gingivitis, though to varying degrees. In one meta-analysis comparing prescription-strength and over-the-counter solutions, products like Listerine wound up reducing dental plaque in patients by between 13 percent and 56 percent, with a reduction in gingivitis of between 14 percent and 36 percent. Non-alcoholic rinses, such as Crest Pro-Health, had a 15 percent effect on plaque and gingivitis, respectively.

So does mouthwash really work? Unfortunately, the statistics are silent on the matter of bad breath -- which is the reason many of us probably use mouthwash in the first place. Still, what the manufacturers write on the bottle isn't all hype.

Jump to comments
Presented by

Brian Fung is the technology writer at National Journal. He was previously an associate editor at The Atlantic and has written for Foreign Policy and The Washington Post.

Get Today's Top Stories in Your Inbox (preview)

Why Do People Love Times Square?

A filmmaker asks New Yorkers and tourists about the allure of Broadway's iconic plaza

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register. blog comments powered by Disqus


Why Do People Love Times Square?

A filmmaker asks New Yorkers and tourists about the allure of Broadway's iconic plaza


A Time-Lapse of Alaska's Northern Lights

The beauty of aurora borealis, as seen from America's last frontier


What Do You Wish You Learned in College?

Ivy League academics reveal their undergrad regrets


Famous Movies, Reimagined

From Apocalypse Now to The Lord of the Rings, this clever video puts a new spin on Hollywood's greatest hits.


What Is a City?

Cities are like nothing else on Earth.



More in Health

Just In