Does mouthwash kill COVID-19?

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COVID-19 is a highly infectious disease caused by the SARS-CoV-2 virus. Most people who contract COVID-19 experience mild to moderate symptoms and recover without special treatment. However, some people become severely ill and require medical attention. Any person can contract COVID-19 and become seriously ill or die.

The virus can transmit from the nose or mouth of a person with COVID-19 through small particles when they sneeze, cough, breathe, sing, or speak.

Symptoms of COVID-19 include:

• cough
• difficulty breathing
• shortness of breath
• fever
• chills
• headaches
• body or muscle aches
• fatigue
• loss of smell or taste
• congestion or runny nose
• sore throat
• diarrhea
• nausea or vomiting

According to the World Health Organization (WHO), there have been more than 550 million confirmed cases of COVID-19 and more than 6 million deaths globally. To help prevent the virus, the Centers for Disease Control and Prevention (CDC) recommend that every person aged 6 months and older receive vaccinations.

According to the CDC, more than 222 million people in the United States are fully vaccinated.

Dentists currently use antimicrobial mouthwashes to reduce the number of microorganisms in liquid particles that may escape a person’s mouth during procedures. These rinses contain antiseptic chemicals, which include:

• hydrogen peroxide
• chlorhexidine gluconate
• povidone-iodine
• cetylpyridinium chloride

Research suggests that using mouthwash may temporarily prevent the transmission of SARS-CoV-2 during dental procedures. However, a person can still exhale the virus from their lungs and nasal cavity.

Emerging studies suggest that although they are not primary targets for infection, the salivary glands and throat are important sites of virus transmission and replication in the early stages of COVID-19. This may mean that using mouthwash could be a helpful tool for preventing the spread of the virus.

However, at this stage, studies are too small and short term for researchers to make conclusive statements, and further research is necessary.

A 2020 study suggested that mouthwashes containing certain ingredients may break down or destroy the SARS-CoV-2 viral lipid envelope, which acts as protection for the virus.

The authors stated that published research supports the theory that oral rinsing helps break down viral envelopes in other viruses, including coronaviruses, and should be researched further in relation to COVID-19.

Another 2020 study found that after swishing and gargling a mouthwash formulation for 60 seconds, 16 out of 33 study participants became Neisseria gonorrhea culture-negative within 5 minutes, compared to 4 of 25 participants who gargled saline.

However, the study was not large enough to provide conclusive evidence and indicated a need for further research.

The authors of a 2021 study suggested that oral rinses containing 0.5% povidone-iodine may interrupt the attachment of SARS-CoV-2 to tissues in the nose, throat, and mouth, and lower viral particles in the saliva.

Research limitations

Although research is promising, recent studies have limitations and are insufficient to prove that mouthwash can act as a preventive measure against COVID-19.

Available, published studies are small, and there are no large-scale clinical studies that provide evidence of mouthwash as a successful measure against COVID-19.

Researchers that suggested mouthwash as a promising measure generally also suggested that further research is needed, and did not offer recommendations for the use of mouthwash as a COVID-19 prevention tool.

While researchers have found evidence that certain mouthwash formulas could successfully destroy the virus, the results were only true for people who had only had the virus for a short while.

While some studies found that mouthwash could create a hostile environment for the SARS-CoV-2 virus, research does not support that it can treat active infections or control the spread of the virus.

Finally, although mouthwash may have an effect on the virus in the mouth and throat, COVID-19 also collects in nasal passages. Even if mouthwash could effectively kill the virus in the throat, it would remain in the nasal passages, which could pass the virus down to the throat.

According to the CDC, to prevent infection and the transmission of SARS-CoV-2, a person should consider:

• getting fully vaccinated
• self-isolating if they are infected
• wearing a mask in public spaces
• washing their hands regularly with soap
• using hand sanitizer that contains at least 60% alcohol when soap is unavailable
• staying 6 feet away from other people in public spaces
• covering their mouth and nose when coughing or sneezing
• cleaning and disinfecting surfaces regularly
• getting tested if they may have the virus
• avoiding crowds and poorly ventilated areas
• taking precautions when traveling

Research has shown that using certain formulations of mouthwash may help destroy the protective SARS-CoV-2 viral envelope and kill the virus in the throat and mouth. However, current studies have serious limitations.

Publically available studies do not provide large-scale, clinical evidence to conclude the efficacy of mouthwash against COVID-19. Although mouthwash affects the virus in the mouth and throat, it does not affect the virus in other primary spots such as the nasal passages, which may reinfect the throat.

Research does not show that mouthwash can treat active infections or prevent virus transmission.

Therefore, people should continue adhering to current prevention measures, such as vaccination and regular handwashing. They should also continue to follow measures suggested by the CDC to help stop the transmission of SARS-CoV-2.