Scientists around the world have been working hard to decrease and eliminate the spread of the novel coronavirus.
Recently, several studies were published regarding the use of nasal and oral rinses to kill COVID-19.
Studies have confirmed that certain mouthwashes may inactivate the COVID-19 virus in your mouth with 30 or more seconds of contact.3
However, these findings do not confirm that mouthwash can help reduce the transmission of COVID-19. Mouthwash and nasal rinses are not effective treatments for the virus.
Even the makers of Listerine provided a statement on the subject. The brand confirmed that were was no evidence-based research on the effectiveness of using Listerine mouthwash to prevent the spread of COVID-19.8
More research is necessary to confirm the virucidal properties of mouthwashes and whether they can help stop the spread of COVID-19.
In July, The Journal of Infectious Diseases published a study from a team of scientists in Germany. The study showed how over-the-counter mouthwashes affected the viral load of three different strains of Covid.1
All the mouthwashes were effective at reducing the viral load.
However, only three mouthwashes could reduce viral inactivity by up to three orders of magnitude to background levels.
These mouthwashes were:
In September, researchers from Pennsylvania State University College of Medicine published an article in the Journal of Medical Virology.
The article detailed the results of their experiments with nasal and oral rinses. Their research showed similar results.
Three Oral rinses with hydrogen peroxide as the active ingredient could reduce the virus by 90 to 99 percent.2
These mouthwashes included:
Crest Pro-Health was more effective. It decreased infectious virus rates by 99.9 or 99.99 percent.
Listerine Antiseptic was the most effective oral rinse in this trial. It decreased the infectious virus levels by greater than 99.99 percent.
A third study by Cardiff University published their initial findings in November. It also aligned with the other studies.3
Before the Covid-19 Pandemic, nasal sprays were used effectively to decrease bacterial and viral loads from the sinuses.
Now scientists are actively studying if nasal rinses can help combat the viral load and transmission of Covid.
The study at Pennsylvania State University College of Medicine also examined how nasal rinses can inactivate the virus.
They noted that the over-the-counter saline nasal rinse (Neti Pot) had no effect on the virus.
However, a one percent baby shampoo solution could inactivate more than 99 percent of the virus. Inactivity occurred after one minute of contact. It inactivated over 99.9 percent of the virus after two minutes of contact.2
Some studies show that an antiseptic nasal spray may effectively kill the virus in as little as 15 seconds.7
Some hospitals are using this method to protect busy areas like waiting rooms and clinics.
These results show that there is virucidal potential in both oral and nasal rinses.
More research is needed to confirm the virucidal abilities of mouthwashes. More research is also necessary to determine if mouthwash or nasal rinses can help reduce the spread of COVID-19.
You should not use mouthwash as a replacement for other methods of risk reduction.
Mouthwash is not a cure for COVID-19.
Certain mouthwashes may have the potential to help with risk reduction. This is especially in dental settings where aerosol production is high.
However, to stop the spread of the COVID-19 virus, you should continue to do the following:
• Wear a mask
• Social distance
• Wash your hands often
(1) Meister, Toni Luise, et al. “Virucidal Efficacy of Different Oral Rinses Against Severe Acute Respiratory Syndrome Coronavirus 2.” The Journal of Infectious Diseases, vol. 222, no. 8, 29 July 2020, pp. 1289–1292
(2) Meyers, Craig, et al. “Lowering the Transmission and Spread of Human Coronavirus.” Journal of Medical Virology, 17 Sept. 2020
(3) Statkute, Evelina, et al. “Brief Report: The Virucidal Efficacy of Oral Rinse Components Against SARS-CoV-2 In Vitro.” 13 Nov. 2020
(4) Cavalcante-Leão, Bianca L et al. “Is there scientific evidence of the mouthwashes effectiveness in reducing viral load in Covid-19? A systematic review.” Journal of clinical and experimental dentistry vol. 13,2 e179-e189. 1 Feb. 2021, doi:10.4317/jced.57406
(5) Carrouel, F et al. “Antiviral Activity of Reagents in Mouth Rinses against SARS-CoV-2.” Journal of dental research vol. 100,2 (2021): 124-132. doi:10.1177/0022034520967933
(6) de Toledo Telles-Araujo, Gabriel et al. “Potential mouth rinses and nasal sprays that reduce SARS-CoV-2 viral load: What we know so far?.” Clinics (Sao Paulo, Brazil) vol. 75 e2328. 27 Nov. 2020
(7) Frank, Samantha et al. “In Vitro Efficacy of a Povidone-Iodine Nasal Antiseptic for Rapid Inactivation of SARS-CoV-2.” JAMA otolaryngology-- head & neck surgery vol. 146,11 (2020): 1054-1058
(8) Listerine usage guidelines and COVID-19, Listerine