Gargling salt water helps a sore throat because salt draws out excess fluid, easing swelling and clearing mucus and germs.
Why it works
Salt water is hypertonic. It draws excess fluid out of swollen throat tissue by osmosis, easing pain. It may also loosen mucus.
How to
Mix 1/2 teaspoon of salt in 8 oz warm water. Gargle for 30 seconds, spit and repeat up to 4 times a day.
Evidence
A Japanese study found gargling water lowered respiratory infections by 36%.
Not a cure
It only eases symptoms.
See a doctor
If sore throat lasts over a week or comes with fever.
Osmosis
Salt water is hypertonic compared to swollen throat tissues. Through osmosis, it draws extra fluid out of inflamed tissues, which can reduce swelling and ease discomfort. It may also loosen mucus.
Recipe
Mix 1/4 to 1/2 teaspoon of table salt in 8 ounces (240 milliliters) of warm water. Gargle for about 30 seconds, spit it out and repeat several times a day.
Evidence
A 2005 randomized trial of 400 adults in the American Journal of Preventive Medicine found that people who gargled with water three times a day had about 36% fewer upper respiratory tract infections than controls. A 2013 study in Japan found that gargling was effective for preventing colds. A 2019 review concluded that salt water gargling may relieve sore throat symptoms, though quality evidence is limited.
What it does not do
It doesn’t cure the infection or kill all bacteria or viruses. It provides temporary symptom relief.
Other remedies
- Warm tea with honey (not for infants under one year).
- Throat lozenges.
- Humidifier.
- Drinking fluids.
- Pain relievers like acetaminophen or ibuprofen.
- Rest.
Causes of sore throat
Most are viral (colds, flu, COVID-19). About 5% to 15% of adult sore throats are strep throat. Allergies, dry air and acid reflux can also cause irritation.
Safe use
Do not swallow the salt water. Avoid for young children who cannot gargle. People on low sodium diets should spit it out.
See a doctor if
A sore throat lasts more than a week, comes with fever above 101 degrees F, white patches, swollen glands, rash, trouble swallowing or breathing, or drooling. Strep throat needs antibiotics to prevent complications.
Recipe and evidence
A common recipe is 1/4 to 1/2 teaspoon of salt in 8 ounces of warm water, gargled for 15 to 30 seconds and spit out, up to a few times a day. Salt water is hypertonic, so it draws fluid out of swollen throat tissue, which can reduce swelling and thin mucus. Clinical evidence is limited but supportive: a 2005 Japanese trial found people who gargled water had fewer upper respiratory infections than controls, and many doctors recommend it as a low risk comfort measure. It does not kill the virus or cure strep throat.
Limits and safety
Most sore throats, 80 to 90 percent in adults, are viral, while strep causes about 10 percent in adults and 15 to 30 percent in children and needs antibiotics. Other relief includes honey for adults and children over 1 year, lozenges, fluids, humidifier and acetaminophen or ibuprofen. Do not swallow the solution, and avoid gargling in young children who cannot spit it out. See a doctor for sore throat lasting more than a week, with fever over 101 F, trouble swallowing or breathing, drooling, rash or swollen glands.
Based on data from the Mayo Clinic and the Cochrane Library
