Mouthwashes with CPC Reduce the Infectivity of SARS-CoV-2 Variants In Vitro

J Dent Res. 2021 Oct;100(11):1265-1272. doi: 10.1177/00220345211029269. Epub 2021 Jul 20.


Oral mouthwashes decrease the infectivity of several respiratory viruses including SARS-CoV-2. However, the precise agents with antiviral activity in these oral rinses and their exact mechanism of action remain unknown. Here we show that cetylpyridinium chloride (CPC), a quaternary ammonium compound in many oral mouthwashes, reduces SARS-CoV-2 infectivity by inhibiting the viral fusion step with target cells after disrupting the integrity of the viral envelope. We also found that CPC-containing mouth rinses decreased more than a thousand times the infectivity of SARS-CoV-2 in vitro, while the corresponding vehicles had no effect. This activity was effective for different SARS-CoV-2 variants, including the B.1.1.7 or Alpha variant originally identified in United Kingdom, and in the presence of sterilized saliva. CPC-containing mouth rinses could therefore represent a cost-effective measure to reduce SARS-CoV-2 infectivity in saliva, aiding to reduce viral transmission from infected individuals regardless of the variants they are infected with.

Keywords: COVID-19; airborne transmission; cellular infection; coronaviruses; oral hygiene; virucide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19*
  • Cetylpyridinium / pharmacology
  • Humans
  • Mouthwashes* / pharmacology
  • SARS-CoV-2


  • Mouthwashes
  • Cetylpyridinium