Mouthwash Could Inactivate Coronavirus, Preliminary Studies Show

Mouthwashes may help lower the transmission and spread of the coronavirus, according to a new study.

In the study, published in the Journal of Medical Virology, researchers investigated over-the-counter mouthwashes and nasal rinses commonly found in drug stores and supermarkets, since both types of products “directly impact the major sites of reception and transmission of human coronaviruses (HCoV)” — namely, the mouth and nose — and “may provide an additional level of protection against the virus.”

To find out whether mouthwashes and nasal rinses would be effective against the coronavirus, the researchers tested a common human coronavirus known as 229e — one of several strains that typically only cause mild infections like the common cold, according to the Centers for Disease Control and Prevention — not SARS‐CoV‐2, which is the virus associated with COVID‐19.

However, the lead author of the study, Craig Meyers, tells Yahoo Life, all coronaviruses have something in common: “They have a membrane,” says Meyers, a distinguished professor of microbiology and immunology at Penn State.

“With membrane viruses, all you have to do is break that membrane and they’re inactivated,” Meyers explains. “It’s very difficult to work with the actual COVID-19 virus. But the membranes [in coronaviruses in general] are pretty much the same.”

The researchers tested whether certain nasal rinses, such as Neti Pot with a salt/baking soda solution and a diluted 1 percent Johnson’s Baby Shampoo solution and mouthwashes, including Listerine Antiseptic, Listerine Ultra, Orajel Antiseptic Rinse, and Crest Pro‐Health, could inactivate high concentrations of human coronaviruses after using the products for 30 seconds, one minute, and two minutes.

The results: The Listerine mouthwashes, as well as Crest Pro-Health, Equate Antiseptic mouthwash, and CVS Antiseptic mouthwash, were “highly effective at inactivating infectious virus with greater than 99.9 percent,” according to the researchers in the study — even after only swishing around the mouthwash for 30 seconds.

The researchers also found that the mouthwash products with hydrogen peroxide (H2O2) as their active ingredient — such as CVS’ Peroxide Sore Mouth and Orajel Antiseptic Rinse — “all demonstrated similar abilities to inactivate” the human coronavirus 229e by 90 to 99 percent.

With nasal rinses, the researchers found that using a 1 percent baby shampoo solution for either one to two minutes inactivated more than 99 percent of the virus in both cases. But the over‐the‐counter saline nasal rinse, Neti Pot, had “no effect on the infectivity of the virus at any incubation time tested.”

The researchers concluded that these commonly-available healthcare products have “significant virucidal properties with respect to” human coronaviruses.

However, more research is needed — namely, clinical trials to pinpoint which ingredient or combination of ingredients is breaking the virus’ membrane. Meyers tells Yahoo Life that he hopes to get funding to test which ingredients are the most effective.