Hydrogen peroxide is an antiseptic frequently used to clean minor cuts or disinfect surfaces. Due to its versatility, hydrogen peroxide is a staple in many medicine cabinets and first aid kits, and it is readily available at most drug stores.

Some people gargle with hydrogen peroxide to benefit from its cleansing properties.

The liquid contains oxygen and hydrogen molecules. It is an oxidizing agent, which means that it can kill living cells, such as bacteria.

Different strengths, or concentrations, of hydrogen peroxide are available, depending on its intended use. High concentrations are typical in industrial production. The most common concentration sold for household use is 3 percent.

What are the potential benefits of gargling with hydrogen peroxide, and is it safe to use? Continue reading to find out.

Uses and benefits

The possible benefits of gargling hydrogen peroxide include:

Whitening teeth

gargling hydrogen peroxide
Many types of toothpaste and mouthwash contain hydrogen peroxide.

Hydrogen peroxide is a bleaching agent. In fact, many types of toothpaste and mouthwash in stores already contain this compound.

In one study, researchers investigated whether hydrogen peroxide mouthwashes or a 10 percent carbamide peroxide gel could whiten teeth more effectively.

The study involved 50 bovine teeth stained with tea, and the results indicated that over time, the hydrogen peroxide mouthwashes significantly increased the whiteness of the teeth.

However, they were not as effective as the 10 percent carbamide peroxide gel.

Easing a sore throat

One cause of a sore throat is a bacterial infection. Gargling with hydrogen peroxide may ease discomfort by reducing the number of bacteria in the mouth and helping clear the infection.

Hydrogen peroxide may help kill bacteria by releasing oxygen, which alters the environment of anaerobic bacteria and inhibits their growth.

Treating gum disease

Because of its antibacterial properties, hydrogen peroxide may help treat gum disease.

Plaque that forms on the teeth contains a slimy film of bacteria called a biofilm. Hydrogen peroxide releases oxygen that helps destroy the bacteria.

A 2017 randomized trial divided 53 participants into groups to test hydrogen peroxide as a treatment for gum disease.

One group received root debridement and hydrogen peroxide, and the other group just received root debridement.

The results indicated that the hydrogen peroxide group had significantly fewer signs of gum disease by the end of the study, compared to the group that had received root debridement alone.

One advantage of gargling with a hydrogen peroxide solution is it can reach the back of the mouth and spots that may be hard to reach with dental floss.

Diminishing minor mouth sores

Gargling with hydrogen peroxide may help treat minor mouth irritations, such as cuts or canker sores, because it is an antiseptic.

When put on a cut, hydrogen peroxide bubbles or foams as it releases oxygen. The foaming helps clean the area, remove dead cells, and reduce bacteria.

Hydrogen peroxide needs time to work. Since gargling is relatively quick, it will not kill all the bacteria in the mouth, but it may reduce the count.

How to use hydrogen peroxide

gargling hydrogen peroxide in mouth
A person should gargle for around 30 seconds, swishing the solution all around the mouth.

It is important to know how to use a hydrogen peroxide solution correctly to get the most benefits and avoid unwanted side effects.

To gargle with hydrogen peroxide:

  • Use a 3 percent concentration of hydrogen peroxide. Anything stronger is likely to cause irritation.
  • Mix two parts water with one part hydrogen peroxide.
  • Gargle, swishing the solution all around the mouth.
  • Tilt the head back and continue gargling for 30 seconds.
  • Spit the solution out.

The hydrogen peroxide may cause some foaming in the mouth, which is normal.

To avoid irritating the gums, consider limiting use to a few times a week.

Safety and risks

Hydrogen peroxide is safe for most people if they use it correctly. However, the compound can be harmful if a person uses it too often or if the concentration is too strong.

People should never gargle with food-grade hydrogen peroxide, which has a concentration of 35 percent. If a person accidentally swallows it, this can lead to serious gastrointestinal problems.

When mixing the solution, avoid inhaling hydrogen peroxide, as it can cause irritation in the lungs.

The compound can also irritate the eyes, so when spitting out the solution, take care to prevent it from splashing back toward the face.

Avoid swallowing hydrogen peroxide. Although swallowing small amounts of a 3 percent concentration usually does not cause serious problems, it may result in stomach upset and vomiting.

Children should not gargle with hydrogen peroxide if there is any danger of them swallowing it.

In rare cases, more serious side effects are possible. This 2016 medical report describes a person developing chemical colitis and gastritis after using a 3 percent hydrogen peroxide mouthwash during a dental procedure.

If irritation develops after gargling, and it does not go away in a few hours, stop using hydrogen peroxide for this purpose.


Gargling with hydrogen peroxide may help whiten teeth or reduce the number of bacteria in the mouth. However, it is vital to use a concentration no stronger than 3 percent and to use it in moderation to avoid irritation.

Anyone with questions or concerns about using hydrogen peroxide as a mouthwash should speak to a dental professional.

Hydrogen peroxide is available in many pharmacies and online.