Salt Water Gargles and Nasal Rinses: What Sources Say and the Water Safety Rule
What sources say about salt water gargles and saline nasal rinses, and the water-safety rule from the FDA: distilled, sterile or boiled-and-cooled water, never straight tap water.
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The claim as marketed: a salt water gargle or a saline nasal rinse is a gentle, natural way to ease a sore throat or a stuffy nose. What we found: both are mainstream, low-cost habits, and the evidence for them is modest. The one rule that matters most is about the water used for the nose.
The water-safety rule for nasal rinsing
The US Food and Drug Administration (FDA) says to rinse only with distilled, sterile or previously boiled water. [1] It says tap water is not safe for a nasal rinse because it is not adequately filtered or treated. [1] Some tap water carries low levels of organisms, including amoebas, that may be safe to swallow because stomach acid kills them. [1] In the nose, though, those organisms can stay alive and cause potentially serious infections, and the FDA notes they can even be fatal in rare cases. [1]
The FDA page lists the safe water types: distilled or sterile water labeled as such, tap water boiled for 3 to 5 minutes and then cooled until lukewarm, or water passed through a filter designed to trap infectious organisms. [1] It also says to wash the device and let it dry between uses. [1] We could not read the CDC's own pages directly, so this section rests on the FDA page, which cites the CDC.
If your immune system is not working properly, the FDA says to check with your health care provider before using any nasal irrigation system. [1] If symptoms get worse, or you develop fever, nosebleeds or headaches while rinsing, it says to go back to your health care provider. [1] Problems with these devices can be reported to the FDA's MedWatch program; see Side Effects, Allergic Reactions and Reporting.
Salt water gargles: what sources say
Mainstream advice. The UK National Health Service (NHS) lists gargling with warm, salty water among ways to soothe a sore throat, and says children should not try it. [2] It says to spit the solution out and not swallow it. [2] The NHS adds that sore throats are usually caused by viruses or smoking and normally get better within a week. [2]
Research. The best-known gargling trial we read tested plain water, not salt water. In 387 healthy adults followed for 60 days in Japan, water gargling was linked to fewer upper respiratory infections than usual care. [3] The group using diluted povidone-iodine did not show a clear difference from usual care in that trial. [3]
Proper evidence not found for salt water specifically versus plain water. We searched PubMed for gargle trials involving saline or salt water and found no trial comparing the two that we could read. The NHS advice is common-practice guidance, and we did not find in its text a trial it relies on.
Saline nasal rinses: what reviews found
| Question | What the source found | Strength of evidence |
|---|---|---|
| Do saline rinses help nose and sinus conditions? | A 2022 systematic review of 69 studies recommended nasal saline for most sinonasal diseases, with results varying by condition and device. [4] | Promising but limited |
| Which saline strength is gentler? | The same review found isotonic saline preferred over hypertonic saline because of fewer adverse events. [4] | Promising but limited |
| How firm are the trial results? | A 2026 review of eight trials found moderate-to-high statistical fragility: small outcome changes could reverse conclusions. [5] | Mixed |
These results are for rinses made and delivered as in those studies; they do not tell you that home-mixed solutions or any particular device perform the same way.
When to see a clinician
The NHS lists trouble breathing, being unable to swallow and drooling as emergency signs for a sore throat. [2] In the US, call 911 for those. See a clinician if a sore throat lasts more than a week, keeps returning, or comes with a very high temperature. [2] For children, ask a pediatrician first: the FDA says very young children may not tolerate rinsing, and some could use it from about age 2 if a pediatrician recommends it. [1]
Related reading: Natural Does Not Mean Safe, Detox Claims Checked and Baking Soda: Household Uses and Health Claims Checked.
Frequently asked questions
Can I use tap water in a neti pot?
The FDA says tap water is not safe for a nasal rinse because it is not adequately filtered or treated. [1] It lists distilled or sterile water, previously boiled and cooled water, or specially filtered water as safe types. [1]
Why is tap water a problem in the nose but fine to drink?
The FDA explains that organisms in some tap water may be harmless to swallow because stomach acid kills them, but can survive in the nasal passages and cause serious infections. [1]
Does a salt water gargle cure a sore throat?
No source we read says it cures one. The NHS lists it as a way to soothe a sore throat, notes sore throats usually clear within a week, and says children should not try it. [2]
Is plain water gargling any different from salt water?
A randomized trial in healthy adults found fewer upper respiratory infections with plain water gargling than with usual care. [3] We did not find a readable trial comparing salt water with plain water.
Should I swallow the gargle?
The NHS says to spit it out and not swallow it. [2] If a child or anyone swallows a large amount of salt solution and seems unwell, call Poison Help at 1-800-222-1222 (US).
References
- U.S. Food and Drug Administration, Is Rinsing Your Sinuses With Neti Pots Safe? (consumer update, current as of 04/28/2025). Read 2026-10-23.
- NHS (UK), Sore throat (page last reviewed 08 April 2024). Read 2026-10-23.
- Satomura K et al., Prevention of upper respiratory tract infections by gargling: a randomized trial. Am J Prev Med 2005. Read 2026-10-23.
- Optimal Device and Regimen of Nasal Saline Treatment for Sinonasal Diseases: Systematic Review. PubMed 35720767. OTO Open 2022. Read 2026-10-23.
- The Statistical Fragility of Saline Nasal Irrigation for Rhinosinusitis: A Systematic Review. PubMed 42053165. The Laryngoscope 2026. Read 2026-10-23.