A New Study Says Mouthwash Could Kill COVID-19, So We Checked with Doctors to See If It's Too Good to Be True

covid mouthwash cat

What if a common household item most of us have in our medicine cabinet could kill the coronavirus? That's the exact question we pondered when we saw, earlier this week, a new study by researchers from Cardiff University in the UK that analyzed the ability of mouthwash the kill the coronavirus. Taken at face value, this is great news, but according to doctors we spoke to, it's probably too good to be true. Read on for everything you need to know about mouthwash and COVID-19—and why you probably shouldn't worry about stocking up on Listerine right now. 

The study didn't use real mouths

Dr. Caesar Djavaherian's, co-founder and Chief Clinical Innovation Officer of Carbon Health, tells us, "The study was performed in the laboratory and without using real mouths for the mouthwash, but by mimicking what the mouth environment is like and determined that mouthwash can kill the virus." Because of that, Dr. Djavaherian tells us, we can't know whether mouthwashes can actually prevent infections in real mouths of real humans. That type of information, he says, "would be useful, but studying it would be unethical because you’d have to try to infect real humans with a virus as you studied whether mouthwash protected the patients." Dr. Nate Favini, Medical Lead of Forward, concurs, telling us that while it is accurate to say that mouthwash kills the virus because it's destroying viral particles, "This doesn’t mean that it kills all of the virus in your body, just that if you mix the virus and mouthwash in a test tube, the virus does die." He adds that, " It would be highly inaccurate to say that mouthwash cures coronavirus."

It's too early to tell if it could actually work

The study's results might be promising, but Dr. Favini says it's too early to tell if it will be useful. "It’s not surprising that the ingredients in mouthwash (Cetylpyridinium chloride) can kill the virus in laboratory conditions," he tells us. "What will make these results more meaningful is studying it in people, which is the next step for the researchers." His takeaway from the study? " I suspect that the frequency you’d have to use mouthwash to reduce viral transmission would be really high and so I doubt that mouthwash is going to reduce COVID-19 transmission in a meaningful way. I’d love to be surprised though."

The bottom line

Per Dr. Favini, "With vaccines making progress, I don’t expect this to become a major tool in our toolkit against COVID-19." His suggestion? Keep wearing your mask, since "Widespread mask use is likely to be much more effective than mouthwash for reducing spread of the virus." Roger that, we're in the market for a cool new one anyway. 

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sarah stiefvater

Wellness Director

Sarah Stiefvater is PureWow's Wellness Director. She's been at PureWow for ten years, and in that time has written and edited stories across all categories, but currently focuses...