An antiseptic and oxidising agent for cleaning wounds and as a mouthwash
Hydrogen peroxide
An antiseptic and oxidising solution used to clean minor wounds and as a mouthwash, which foams on contact.
What is Hydrogen peroxide?
Hydrogen peroxide is a long-established antiseptic and oxidising agent used to clean minor wounds and grazes and, in a milder form, as a mouthwash for mouth and gum problems. It works by releasing oxygen on contact, which is why it foams and bubbles and helps lift away debris. The most important things to know are that it can damage healthy tissue and slow healing if used too strongly or too often, that it should not be used on deep, large or closed wounds where it can cause harm, and that the mouthwash form is much weaker than wound solutions and should not be swallowed.
Education and reference only. This is a plain-language guide to Hydrogen peroxide — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Hydrogen peroxide is an antiseptic that also acts as an oxidising agent, meaning it works by releasing oxygen when it touches tissue or germs. It is used to clean minor wounds, cuts and grazes and to help loosen and lift away dirt and debris, and a much weaker mouthwash form is used for mouth and gum problems such as minor infections or ulcers. It is available as solutions and creams of differing strengths for the skin, and as a dilute mouthwash for the mouth. It is a familiar, widely available antiseptic that has been used for many years.
How it works
When hydrogen peroxide meets tissue or germs, it quickly breaks down and releases oxygen, which is what makes it foam and bubble. This burst of oxygen is harmful to many germs and helps physically lift dirt, debris and loose material out of a wound as it fizzes, giving a cleaning effect. The same oxidising action that harms germs can also harm healthy cells if the solution is too strong or used too much, which is why milder strengths are used and why it is not suited to delicate or deep wounds. As a mouthwash, a very dilute form provides a gentler version of this cleaning and antiseptic action in the mouth.
Company & origin
Originated / developed by: Various manufacturers.
A long-established antiseptic used in the UK for cleaning minor wounds and as a mouthwash for mouth and gum problems.
Practical use
How to take Hydrogen peroxide
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Use the right strength for the job: a weak mouthwash form for the mouth and an appropriate skin solution for minor wounds.
- Use it on minor cuts and grazes to help clean them, rather than on deep, large or closed wounds.
- Do not use it repeatedly over a long time on a healing wound, as it can slow healing.
- Use the mouthwash as directed and do not swallow it; rinse and spit it out.
- Keep it away from the eyes, and avoid stronger solutions on healthy or delicate skin.
Weighing it up
Advantages & disadvantages of Hydrogen peroxide
Advantages
- A familiar, widely available antiseptic for cleaning minor wounds and grazes.
- Foams on contact, which helps lift away dirt and debris from a wound.
- A dilute mouthwash form can help with minor mouth and gum problems.
Disadvantages
- Can damage healthy tissue and slow healing if used too strongly or too often.
- Not suitable for deep, large or closed wounds, where it can cause harm.
- Stronger solutions can burn the skin or eyes, and the mouthwash must not be swallowed.
Practical use
Good to know
The key things to understand about hydrogen peroxide are about using it carefully. While it cleans well by fizzing and lifting debris, the same oxidising action can damage healthy tissue and slow wound healing if it is too strong or used too often, so milder strengths are used and it is not meant for repeated long-term use on a healing wound. It should not be poured into deep, large or closed wounds, or into body cavities, because the oxygen it releases has nowhere to escape and can cause harm. The strength matters a great deal: mouthwash preparations are much weaker than wound solutions, the two are not interchangeable, and stronger solutions can burn the skin or eyes. The mouthwash form should be used as directed and not swallowed, and any solution should be kept away from the eyes.
Who should not take it / use with caution
- It should not be used in deep, large or closed wounds, or in body cavities, where released oxygen can cause harm.
- People who have had a reaction to hydrogen peroxide or similar antiseptics should avoid it.
- Strong solutions should not be used on healthy or delicate skin, near the eyes, or be swallowed.
Monitoring
- Checking that minor wounds are healing and not becoming irritated by repeated use.
- Watching for skin irritation, stinging or whitening where it is applied.
- Seeking medical advice for wounds that are deep, large, not healing, or showing signs of infection.
Side effects
- Stinging, irritation or whitening of the skin where it is applied.
- Slower wound healing or tissue damage if it is too strong or used too much.
- Mouth or gum irritation with the mouthwash; burns to the skin or eyes from stronger solutions.
Key interactions
- It can be inactivated or made less effective by some other wound products, so avoid mixing antiseptics.
- It is generally used on its own for cleaning rather than combined with other solutions.
- Follow the product instructions, as different strengths are intended for different uses.
Available as: Solutions and creams for the skin of differing strengths, and a dilute mouthwash for the mouth.
Answers
Hydrogen peroxide: frequently asked questions
What is hydrogen peroxide used for?
It is an antiseptic used to clean minor wounds and grazes, and a much weaker form is used as a mouthwash for mouth and gum problems.
Why does it foam on my skin?
It releases oxygen when it touches tissue or germs, which makes it fizz and helps lift away dirt and debris from a wound.
Can I use it on a deep wound?
No. It should not be used in deep, large or closed wounds, because the oxygen it releases has nowhere to escape and can cause harm.
Can it slow healing?
Yes, if it is too strong or used too often the same oxidising action that cleans can damage healthy tissue and slow healing, so it is used carefully.
Is the mouthwash the same as the wound solution?
No. The mouthwash form is much weaker; the two are not interchangeable, and the mouthwash should be used as directed and not swallowed.
Authoritative sources
- BNF
- NICE CKS
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