Gargling is an easy way to reduce infection and transmission of viruses. Antiseptic mouthwashes, like Listerine, effectively reduce oro- and nasopharyngeal (mouth, throat and nose) viral load and inactivate coronaviruses.
The nose, throat and salivary glands are major sites of virus replication and transmission during early stages of coronavirus infection, as well as other respiratory viruses and bacteria. Targeting these areas with mouthwashes and nasal rinses can help prevent progression and reduce transmission of the disease.
While the vaccines aim to prevent viruses from replicating in the lungs, they do not prevent viruses from replicating in the nose, mouth and pharynx, which has a different type of mucosa than the lungs and this area is the first area to be infected.
The easiest thing we can do is to gargle daily for prevention of transmission of viruses and bacteria. Alternatively, gargling can be applied after exposure to someone who is sick or potential exposure after flying or being in a crowded place. This can be helpful for all people regardless of vaccination history.
What to gargle and how often:
The most effective mouthwashes, according to studies, are Providine-iodine (Betadine), Listerine Anti-septic with Essential oils, Cetylpryidinium Chloride containing mouthwashes (Scope, Act, Crest) and Hydrogen Peroxide 1.5-3% dilution.
Our family uses Listerine Naturals Antiseptic mouthwash, the dye-free version that contains Listerine’s original 4 essential oils – eucalyptol, menthol, methyl salicylate (wintergreen oil) and thymol. Listerine original antiseptic claims to have antimicrobial properties and to kill the germs that cause bad breath, and it did really well in the studies. The slightly more effective original yellow Listerine has a percentage of higher alcohol (26% vs 21%) and contains more artificial ingredients than the Listerine Naturals (but less than most of the brightly colored versions such as the Cool Mint). Our family chose Listerine over the other mouthwashes for taste, safety and effectiveness.
For prevention: gargling 1-2 x daily for 30 seconds is recommended.
If there is suspected exposure or after being in crowded areas, extra gargling is a great idea.
For early stage treatment: gargling 3 x daily for 30 seconds is recommended for COVID or flu/cold.
Do not swallow mouthwashes.
Listerine’s active ingredients include 4 essential oils: eucalyptol, menthol, methyl salicylate and thymol. Some research uses the classic yellow or the cool mint. Most contain dyes and other chemicals that I usually try to avoid for my family. The classic original yellow Listerine has less chemicals than most, and there is one that is totally free of dyes. So, I am currently stocking a dye-free Listerine – herbal mint – which contains the 4 essential oils, which is Listerine’s secret weapon.
Here are the ingredients in three Listerine products. Note these three all contain the 4 essential oils and the original has a higher percentage of alcohol.
Listerine Naturals Antiseptic:
- Active ingredients: Eucalyptol 0.092%, Menthol 0.042%, Methyl salicylate 0.060%, Thymol 0.064%
- Inactive ingredients: Water, Sorbitol solution, Alcohol (21.6%), Poloxamer 407, Flavor, Benzoic acid, Stevia rebaudiana leaf/stem extract, Sodium benzoate
Listerine Original Antiseptic:
- Active ingredients: Eucalyptol 0.092%, Menthol 0.042%, Methyl salicylate 0.060%, Thymol 0.064%
- Inactive ingredients: Water, Alcohol (26.9%), Benzoic acid, Poloxamer 407, Sodium benzoate, Caramel
Listerine Cool Mint Antiseptic:
- Active ingredients: Eucalyptol 0.092%, Menthol 0.042%, Methyl salicylate 0.060%, Thymol 0.064%
- Inactive ingredients: Water, Alcohol (21.6%), Sorbitol solution, Flavoring, Poloxamer 407, Benzoic acid, Sodium saccharin, Sodium benzoate, FD&C Green No. 3
References: https://onlinelibrary.wiley.com/doi/10.1002/jmv.26514
https://academic.oup.com/jid/article/222/8/1289/5878067
To learn about anti-viral nasal sprays, see my blog post Oral-Nasal Virucidal Therapy.