Gargling for a Sore Throat

Edited Feb-23-2011 by Earl


How does gargling work?  Why does gargling help a sore throat?

It's hard to find definitive information on this online.  This page represents what  I believe to be correct, including references.

Gargling with Salt Water

Salt might make some viruses and bacteria die.  Ever heard that a snail will die in salt water?  Maybe the same is true for some microbes.  Added salt might help, but not required.

Gargling with Chlorinated Water

Salt is not necessary to be helpful.  In other words, there's more to it than just the salt.  In Japan, a study showed that gargling with water alone 3 times a day helped prevent upper respiratory tract infections.  The turbulent action of the liquid helps to flush the viruses and bacteria out the mouth or down into the stomach.  [  Reference: ]  But did their water contain Chlorine?  If so, perhaps the Chlorine in the water helped kill microbes.  [ Idea from ]  Chlorine is added to our city water supply for this very reason:  to kill microbes.  Gargling with chlorinated water might be better than gargling with distilled or filtered water.  Personally, I would spit out the chlorinated water instead of swallowing it.

One tip:  While gargling, make sound with your vocal chords.  This makes the motion of the fluid even more turbulent, which can dislodge food particles, phlegm, and germs from your throat.   [  Reference: ]  This simple act of good hygiene can make the back of your mouth and throat too clean for microbes to grow.  

Drinking Fluids

Drinking clean, unsweetened fluids throughout the day might be as beneficial as gargling.  Choose a clean beverage and avoid the sugar and corn syrup, so you are not feeding the microbes.  Honey might be beneficial as it is antimicrobial.  The liquid going down the back of your mouth and down your throat washes the infection down into your stomach where acids kill many microbes.  The action of drinking liquid washes food particles away that could otherwise feed an infection.  You are washing the microbes off your throat to keep them from multiplying there.

I have heard people preach:  "Drink 8 glasses of water a day."  There is no science behind this chosen volume of water.  However, it might be good for us to drink lots of clean water throughout the day, especially when we are sick, to help wash pathogens out of our throat.

I have noticed that when I have a sore throat, it's always worst in the morning when I first wake up.  I think it's because I have not been drinking fluids or gargling to wash down the infection.  During the night, the infection has a chance to multiply, undisturbed.  Would it be good to get up in the night to gargle and drink a sip of water?  Probably, if you wake up anyway.  Quality of sleep is also important for a good immune system, so I would not force myself up.  But if I wake up anyway in the night, gargling and drinking water might help recover from a sore throat faster.

Gargling with Iodine

Iodine added to salt might help.  Water purification tablets are made with Iodine.  If you are caught outside with an untrusted source of water, like from a stream that could contain living pathogens, Iodine added to the water can kill those pathogens, making the water safer to drink.  If Iodine is good for purifying water, maybe it's good for purifying your throat.  Some salt has added Iodide (an Iodine ion), which might be a good choice to add to your gargling water.

[ Image from

Gargling with Hydrogen Peroxide

H2O2 also kills many pathogens.  The FDA states that H2O2 is an antimicrobial agent.  [ Source: ]  Gargling with H2O2 is another way to disinfect the back of your mouth.  The stuff you buy at the store is too strong a concentration so water it down and save money at the same time.  Personally, I dilute the 3% concentration with an equal part of water, which makes it about 1.5%.  The H2O2 fizzes when it comes in contact with microbes.  If it's not fizzing, you don't have any germs.  

UV Treatment?

Just thinking here... I have seen UV light used to kill pathogens, to purify water, and disinfect toothbrushes.  

These things have been shown to kill pathogens:

Chlorine in city water and swimming pools
Iodine added to outside water
Hydrogen peroxide
UV light used to purify water and clean toothbrushes

Do not try this UV light idea if you cannot verify it is safe.  UV light, also emitted by the sun, may cause DNA damage and cancer.  The back of our throat is not designed to be subjected to this kind of light as it is in a dark place and evolution has seen no reason to protect it from the sun.  There is no protective pigmentation back there like we have on our skin.  But, I think this idea is worth exploring.  I have a UV flashlight.  It has a warning to not point at eyes or skin.

If I had pnuemonia and feared that I might die because the infection was getting out of hand, I might try shining the UV light at the back of my mouth to kill the germs that might end up killing me.  But I would only resort to the UV light if I thought my life were already in danger, as UV light could lead to cancer.  [ Reference: ]  Antibiotics would probably be a safe intermediate step before resorting to UV light.


For now, I'll try to gargle daily with chlorinated, salt water fortified with Iodine and occasionally gargle with about 1.5% H2O2.  I will also drink clean beverages, like unsweetened tea, throughout the day to keep flushing the pathogens down the throat.


Nurse  - March 27, 2013

Hello, Wrong info on hydrogen peroxide. Please do not use on wounds! For years, people have used hydrogen peroxide to clean out wounds. Sometimes it’s used straight and other times diluted with water. Either way, its bubbling action makes it look like it’s doing its job by loosening up dead material and cleaning out bad bacteria. The problem is that hydrogen peroxide not only does this but also damages the healthy cells trying to heal the wound. It can therefore slow down healing, making the wound stay open longer, which can lead to more infections.

Earl - March 27, 2013

I have read a similar comment about H2O2 damaging healthy tissue, but I do not remember where I saw that. But I also have seen people use H2O2 successfully. One man breathes in a H2O2 mist to stay healthy and to fight respiratory infections. Video:

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