Commercial mouthwash reduces SARS-CoV-2 salivary viral load

SARS-CoV-2 has been identified in the saliva of 91.7% of patients infected with the virus. Numerous scientific studies have demonstrated the virus’s transmissibility through saliva up to 3 m, even by asymptomatic patients, or by aerosols up to 8 m.

These findings led the researchers to investigate the efficacy of an antiseptic mouthwash containing the antiviral molecules β-cyclodextrin and Citrox® in reducing the SARS-CoV-2 salivary viral load. The antiviral activity of β-cyclodextrin and Citrox®, an organic bioflavonoid mix, has already been attested, but evidence for their action against SARS-CoV-2 was based only on in silico and in vitro studies.

In the multicentre, double-blind randomised controlled study, 176 patients who had tested positive for SARS-CoV-2 in a polymerase chain reaction test in the last eight days rinsed three times daily for seven days either with the mouthwash containing the antiviral substances or with a placebo. The antiviral mouthwash in question was Curaprox’s ‘Perio plus’ regenerate, provided by Curaden AG. All patients were between 18 and 85 years old, presented with no to mild symptoms and were selected from four French hospital centres. The evolution of the SARSCoV-2 salivary viral load in the patients’ saliva samples was then compared between the group using the antiviral mouthwash and the group using the placebo.

The clinical trial showed that a single rinse with the antiviral mouthwash had a significant effect: the initial SARS-CoV-2 salivary viral load was reduced by 71% 4 hours after the first rinse. According to co-author Prof. Denis Bourgeois, “A single rinse with the β-cyclodextrin–Citrox® mouthwash significantly reduces the risk of SARS-CoV-2 transmission from salivary droplets.”

On the first day, compared with the placebo, the second rinse with the antiviral mouthwash helped to maintain the low viral load achieved after the initial rinse. Seven days after the initial rinse, three daily rinses had a significantly beneficial effect on reducing the SARS-CoV-2 salivary load in the 50% of adults with the highest viral loads at baseline.

1. Carrouel F, Valette M, Gadea E, Esparcieux A, Illes G, Langlois ME, Perrier H, Dussart C, Tramini P, Ribaud M, Bouscambert-Duchamp M, Bourgeois D. Use of an antiviral mouthwash as a barrier measure in the SARS-CoV-2 transmission in adults with asymptomatic to mild COVID-19: a multicenter, randomized, double-blind controlled trial. Clin Microbiol Infect. 2021 May 24:S1198-743X(21)00268-8. doi: 10.1016/j.cmi.2021.05.028. [Link to study]