Skip to product information
1 of 1

  • Images are for illustration purposes only

Colgate Peroxyl Mouthwash 300ml

Colgate Peroxyl Mouthwash 300ml

  • 1. Ozempic®️-equivalent therapy now available for weight management
  • 2. Average weight loss of 17%, with 1 in 3 patients achieving over 20%
  • 3. May help reduce osteoarthritis-related pain
  • 4. Wegovy®️ is not expected to impact the effectiveness of oral contraceptives
  • 5. Supports cardiovascular risk reduction
  • 6. Over 22 million patients treated with semaglutide-based therapies since 2018

  • ✔️ Cleanses mouth ulcers with gentle hydrogen peroxide action
  • ✔️ Soothes minor gum irritation and oral wound discomfort
  • ✔️ Effervescent rinse lifts bacteria and debris from wounds
  • ✔️ Suitable for adults and young people aged 12 and over
  • ✔️ Short-term use supports natural oral tissue healing

Price Checker

Regular price £4.99
Sale price £4.99
Sale Sold out
  • Lowest price guarantee
  • Includes FREE private prescription

Purchase Options

View full details

 

What Is Colgate Peroxyl Mouthwash and What Does It Do?

 

If you have ever dealt with a painful mouth ulcer or a sore patch of gum that just will not settle, you will know how much it can affect eating, drinking, and even speaking. Colgate Peroxyl mouthwash is an antiseptic oral rinse containing 1.5% hydrogen peroxide, specifically formulated to cleanse minor oral wounds, soothe irritated gum tissue, and support the natural healing process inside the mouth. It is available over the counter without a prescription, making it a convenient first-line option for everyday oral discomfort. You can find it alongside other oral health products at Cured Pharmacy for just £4.99.

Mouth ulcers are extremely common in the UK. The NHS notes that most people will experience them at some point, and they can be triggered by minor injury, stress, certain foods, or underlying health conditions. While most ulcers resolve on their own within one to two weeks, an antiseptic rinse can help keep the area clean and reduce discomfort in the meantime.

 

How Does Colgate Peroxyl Mouthwash Work?

 

The active ingredient is hydrogen peroxide at a concentration of 1.5% w/v. When it comes into contact with oral tissues, it undergoes a rapid chemical reaction that releases oxygen. This effervescent, bubbling action is what makes it effective — it physically lifts debris and bacteria from the wound site, helping to keep the area clean without the need for scrubbing or mechanical irritation.

  • Hydrogen peroxide releases nascent oxygen on contact with oral mucosa
  • The oxygen release creates a mild effervescent action that dislodges food debris and bacteria
  • This cleansing effect reduces the bacterial load around ulcers and minor wounds
  • A cleaner wound environment supports the body's own healing mechanisms

It is worth noting that this is not a treatment that numbs pain in the way a topical anaesthetic gel might. Instead, it works by addressing one of the key factors that can slow healing — bacterial contamination and debris accumulation at the wound site.

 

Who Should Use Colgate Peroxyl Mouthwash?

 

This mouthwash is suitable for adults and young people aged 12 and over who are experiencing minor oral discomfort. It is particularly useful for people who develop mouth ulcers regularly, those recovering from minor dental procedures, or anyone with small cuts or abrasions inside the mouth from braces or dentures.

  • Adults with recurrent or painful mouth ulcers
  • People with minor gum irritation or inflamed gum tissue
  • Orthodontic patients experiencing soft tissue irritation from braces
  • Individuals with small oral wounds following dental treatment

It is not intended for children under 12, and it should not be used as a substitute for professional dental care if symptoms are severe, persistent, or accompanied by fever or swollen lymph nodes.

 

How Does Colgate Peroxyl Compare to Other Antiseptic Mouthwashes?

 

Feature Colgate Peroxyl 300ml Corsodyl (Chlorhexidine)
Active ingredient Hydrogen peroxide 1.5% Chlorhexidine gluconate 0.2%
Primary use Oral wound cleansing, ulcer care Gum disease, plaque control
Tooth staining risk Low Known risk with prolonged use
OTC availability Yes Yes

 

Is Colgate Peroxyl Mouthwash Suitable for Sensitive Mouths?

 

Generally speaking, yes — the 1.5% hydrogen peroxide concentration used in Colgate Peroxyl mouthwash is considered mild and well-tolerated by most people. However, if you have a known sensitivity to hydrogen peroxide or experience significant burning or irritation after use, you should discontinue and speak to your pharmacist or dentist. Those with very extensive oral ulceration or wounds that appear infected should seek professional assessment rather than relying solely on an OTC rinse. If you are managing other health concerns alongside your oral care, our dental products collection includes a range of options to support your overall wellbeing.

This product is a medicine. Speak to your doctor or pharmacist before using if you have an underlying medical condition or are taking other medicines.

Colgate Peroxyl Mouthwash 300ml specifications
Treatment category Oral care / antiseptic mouth rinse
Active ingredient Hydrogen peroxide 1.5% w/v
Mechanism of action Releases oxygen on contact with oral tissue, cleansing wounds and reducing bacterial load
Suitable for Adults and children aged 12 and over
Pack size 300ml
UK classification General Sale List (GSL)
Preparation Aqueous oral rinse solution
Route of administration Oral (mouth rinse — do not swallow)

Specifications of Colgate Peroxyl Mouthwash 300ml

 

What Is Colgate Peroxyl Mouthwash and What Is It Used For?

 

Colgate Peroxyl Mouthwash 300ml is an antiseptic oral rinse containing hydrogen peroxide 1.5% w/v. It is used to cleanse and soothe the inside of the mouth, particularly in cases of minor oral wounds, mouth ulcers, gum irritation, and soft tissue injuries caused by dental appliances such as braces or dentures. The NHS advises that mouth ulcers, while usually harmless, can be uncomfortable and benefit from gentle cleansing to support healing. This product is classified as a General Sale List (GSL) medicine in the UK, meaning it can be purchased without a prescription.

 

What Do You Need to Know Before Using Colgate Peroxyl Mouthwash?

 

Before using this mouthwash, read the following carefully. There are certain situations where you should seek advice before proceeding.

Do not use Colgate Peroxyl if you:

  • Are allergic to hydrogen peroxide or any other ingredient in the formulation
  • Are under 12 years of age (use only under dental or medical supervision)
  • Have large, spreading, or infected oral wounds — these require professional assessment
  • Have mouth ulcers that have lasted longer than three weeks without improvement

Speak to your pharmacist or dentist before use if you:

  • Are pregnant or breastfeeding
  • Have a known bleeding disorder affecting the mouth or gums
  • Are currently undergoing chemotherapy or radiotherapy affecting the head and neck

Drug interactions:

  • No clinically significant drug interactions are known at the 1.5% OTC concentration
  • Avoid using simultaneously with other oral rinses unless advised by a dental professional

 

How Should You Use Colgate Peroxyl Mouthwash Correctly?

 

Using this mouthwash correctly is straightforward, but it is important to follow the steps below to get the most benefit and avoid any unnecessary irritation.

  1. Measure approximately 10ml of the mouthwash using the cap or a measuring cup
  2. Take the liquid into your mouth without swallowing
  3. Rinse vigorously around the mouth, ensuring the liquid reaches the affected area
  4. Continue rinsing for approximately one minute
  5. Spit the mouthwash out completely — do not swallow
  6. Do not eat or drink for at least 30 minutes after use if possible
Indication Age Group Dose Frequency
Mouth ulcers / minor oral wounds Adults & children 12+ 10ml Up to 4 times daily
Gum irritation / post-dental care Adults & children 12+ 10ml Up to 4 times daily
Children under 12 Under 12 Not recommended Seek dental advice

If you are looking for additional support for your oral health routine, our oral health collection includes a range of complementary products. For broader health concerns that may be contributing to recurrent mouth ulcers — such as nutritional deficiencies — it may also be worth exploring our vitamins and supplements range.

 

What Are the Possible Side Effects of Colgate Peroxyl Mouthwash?

 

Side effects with Colgate Peroxyl are uncommon when used as directed. The hydrogen peroxide concentration is low, and most people tolerate it well. That said, it is important to be aware of what to look out for.

Common side effects:

  • Mild tingling or fizzing sensation in the mouth during use (this is normal and expected)
  • Temporary mild oral irritation, particularly if the mouth is already inflamed

Less common side effects:

  • Temporary tooth sensitivity
  • Mild soreness of the tongue or inner cheeks
  • Altered taste sensation immediately after use

If you experience a severe burning sensation, swelling of the mouth or throat, or any signs of an allergic reaction such as rash, difficulty breathing, or swelling of the face, stop use immediately and seek urgent medical attention. The NHS advises that allergic reactions to topical oral products, while rare, should always be taken seriously.

 

How Should You Store Colgate Peroxyl Mouthwash Safely?

 

  • Store below 25°C in a cool, dry place away from direct sunlight
  • Keep the bottle tightly closed when not in use
  • Keep out of the reach and sight of children at all times
  • Do not use after the expiry date printed on the bottle
  • Do not store in the bathroom if it is frequently humid — a bedroom or kitchen cupboard is preferable
  • Do not freeze

Written and reviewed by our qualified team

Your safety and success are our highest priorities. Our medical team rigorously evaluates every product and piece of advice we provide, ensuring you receive only the most effective, science-backed solutions available.

Frequently Asked Questions

Where can I buy Colgate Peroxyl mouthwash online in the UK?

You can buy Colgate Peroxyl Mouthwash 300ml online from Cured Pharmacy for just £4.99 with fast UK delivery. It is a General Sale List medicine, so no prescription is needed. Browse our full dental products collection for more oral care options.

How does Colgate Peroxyl mouthwash work in the mouth?

Colgate Peroxyl contains 1.5% hydrogen peroxide, which releases oxygen when it contacts oral tissue. This creates a gentle effervescent action that lifts debris and bacteria away from ulcers and minor wounds. The result is a cleaner wound environment that supports the body's natural healing process.

How do I use Colgate Peroxyl mouthwash step by step?

Measure 10ml using the bottle cap, swirl it vigorously around your mouth for approximately one minute, then spit it out completely — never swallow it. You can use it up to four times daily, ideally after meals and before bed. Avoid eating or drinking for at least 30 minutes after rinsing if possible.

What is the correct dose of Colgate Peroxyl mouthwash for adults?

The recommended dose for adults and young people aged 12 and over is 10ml used as a mouth rinse for around one minute, up to four times per day. Do not exceed four uses in 24 hours. If your symptoms have not improved within seven days, consult your dentist or GP.

What are the side effects of Colgate Peroxyl mouthwash?

Most people experience only a mild tingling or fizzing sensation, which is a normal result of the hydrogen peroxide releasing oxygen. Less commonly, you might notice temporary tooth sensitivity or a slightly altered taste. If you experience significant burning, swelling, or any signs of an allergic reaction, stop use immediately and seek medical advice.

Can children use Colgate Peroxyl mouthwash?

Colgate Peroxyl is not recommended for children under 12 years of age without specific advice from a dentist or doctor. Children aged 12 and over may use it under adult supervision, following the same 10ml dosage as adults. Always keep the bottle out of reach of young children.

Is Colgate Peroxyl mouthwash safe to use during pregnancy?

There is limited specific safety data for hydrogen peroxide mouthwash use during pregnancy, so it is advisable to speak to your midwife, GP, or dentist before using it. Since the product is not swallowed and the concentration is low, many healthcare professionals consider short-term use acceptable, but individual advice is always best. Do not self-medicate without professional guidance during pregnancy.

How long can you use Colgate Peroxyl mouthwash for?

Colgate Peroxyl is intended for short-term use, typically up to seven days for minor oral wounds and ulcers. If your symptoms persist beyond seven days or worsen at any point, you should seek advice from your dentist or GP rather than continuing to self-treat. Prolonged unsupervised use is not recommended.

What happens if I accidentally swallow Colgate Peroxyl mouthwash?

Swallowing a small amount accidentally is unlikely to cause serious harm given the low 1.5% concentration, but it is not intended to be ingested. If a large amount is swallowed, or if a child swallows any quantity, contact NHS 111 or your nearest A&E immediately. Always keep the bottle out of reach of children.

What are the best alternatives to Colgate Peroxyl mouthwash?

Common alternatives include chlorhexidine-based mouthwashes such as Corsodyl, which are particularly effective for gum disease and plaque control, or warm saline rinses for very mild irritation. Your dentist or pharmacist can help you choose the most appropriate option based on your specific symptoms. You can also explore our oral health range for further choices.

Can I use Colgate Peroxyl mouthwash after a tooth extraction?

You should always follow your dentist's specific post-extraction instructions before using any mouthwash. In the first 24 hours after extraction, vigorous rinsing of any kind is generally discouraged as it can dislodge the blood clot and delay healing. After this initial period, your dentist may advise gentle rinsing — ask them directly whether Colgate Peroxyl is appropriate for your situation.

Does Colgate Peroxyl mouthwash stain teeth?

Unlike chlorhexidine-based mouthwashes, which are associated with a known risk of tooth staining with prolonged use, hydrogen peroxide at 1.5% is not typically associated with significant staining. In fact, hydrogen peroxide is an ingredient used in many tooth-whitening products, though the concentration in whitening treatments is considerably higher. Short-term use of Colgate Peroxyl at the recommended dose should not cause discolouration.

Who is eligible to use Colgate Peroxyl mouthwash?

It is suitable for adults and young people aged 12 and over who have minor mouth ulcers, gum irritation, or small oral wounds. It is not suitable for children under 12, and those with severe, spreading, or infected oral conditions should seek professional dental or medical care rather than relying on an OTC rinse. If you have an underlying health condition affecting your mouth, speak to your GP or dentist first.

What does the latest research say about hydrogen peroxide mouthwash?

Research supports the use of low-concentration hydrogen peroxide as a safe and effective oral antiseptic for cleansing minor wounds and reducing bacterial load in the mouth. Studies have found it well-tolerated at concentrations of 1.5–3%, with a good safety profile for short-term use. It is not, however, a substitute for professional dental treatment in cases of significant gum disease or infection.

Can I use Colgate Peroxyl mouthwash if I have braces or dentures?

Yes — Colgate Peroxyl is often particularly useful for people wearing fixed braces or removable dentures, as these appliances can cause minor soft tissue irritation and make it harder to keep the mouth clean. The effervescent action helps reach areas that are difficult to clean mechanically. If you are unsure whether it is appropriate for your specific orthodontic or prosthetic situation, check with your dentist or orthodontist first.

How Should You Use Colgate Peroxyl Mouthwash?

Using Colgate Peroxyl correctly makes a real difference to how effective it is. The technique is simple, but rinsing for the full recommended time and spitting out thoroughly are both important steps that should not be skipped.

What Is the Correct Dose of Colgate Peroxyl Mouthwash?

The dose is the same for all eligible users — 10ml per rinse, used up to four times daily. Do not use more frequently than this, as exceeding the recommended dose does not improve outcomes and may increase the risk of irritation.

When Is the Best Time to Use Colgate Peroxyl Mouthwash?

For the best results, use Colgate Peroxyl after meals and before bed. Using it after eating helps remove food debris from around the affected area, while a bedtime rinse allows the cleansing effect to work overnight when saliva flow is reduced and bacteria can accumulate more easily.

If you are using it four times daily, spacing the doses evenly throughout the day — for example, after breakfast, lunch, dinner, and at bedtime — is a sensible approach. Try not to use it immediately before eating, as this reduces the contact time with the affected tissue.

How Long Can You Use Colgate Peroxyl Mouthwash For?

Colgate Peroxyl is designed for short-term use. Most minor mouth ulcers and oral wounds should show clear signs of improvement within seven days of regular use. If your symptoms have not improved after seven days, or if they worsen at any point during treatment, stop using the mouthwash and consult your dentist or GP promptly.

Prolonged unsupervised use beyond seven days is not recommended. If you find yourself needing to use an antiseptic mouthwash repeatedly over several weeks, this may indicate an underlying condition that requires professional investigation rather than ongoing self-treatment.

Do not exceed the recommended dose. If in doubt, speak to your pharmacist.

Customer Reviews

Be the first to write a review
0%
(0)
0%
(0)
0%
(0)
0%
(0)
0%
(0)

What Are the Most Common Side Effects of Colgate Peroxyl Mouthwash?

The most frequently reported experience when using Colgate Peroxyl is a mild tingling or fizzing sensation in the mouth. This is entirely expected — it is the hydrogen peroxide releasing oxygen on contact with oral tissue, and it is a sign the product is working. It is not a cause for concern in most cases.

  • Mild tingling or fizzing sensation during rinsing
  • Temporary mild irritation of the oral mucosa, particularly if the area is already inflamed
  • Slight foaming in the mouth, which is normal and harmless

What Are the Less Common Side Effects of Colgate Peroxyl Mouthwash?

Less commonly, some people notice other effects that are generally mild and short-lived. These tend to resolve on their own once you stop using the product or reduce the frequency of use.

  • Temporary tooth sensitivity, particularly to hot or cold
  • Altered or metallic taste sensation immediately after rinsing
  • Mild soreness of the tongue or inner cheeks
  • Temporary whitening or blanching of the oral mucosa — this is harmless and resolves quickly

What Are the Serious Side Effects of Colgate Peroxyl Mouthwash?

Serious side effects are rare with this product when used as directed. However, you should be aware of the signs that something more significant may be occurring. A severe or worsening burning sensation that does not settle within a few minutes of spitting out the mouthwash is not typical and warrants attention.

Signs of a serious allergic reaction — though very rare — include swelling of the lips, tongue, or throat, difficulty breathing, a widespread skin rash, or dizziness. If you experience any of these, stop use immediately and call 999 or go to your nearest A&E without delay.

What Should You Do If You Experience Side Effects From Colgate Peroxyl Mouthwash?

For mild side effects such as tingling or temporary sensitivity, no specific action is usually needed beyond continuing to use the product as directed. If the irritation feels uncomfortable, you can try reducing use to twice daily rather than four times. Drinking a glass of water after spitting out the mouthwash may also help ease any residual sensation.

If side effects are persistent, worsening, or causing significant discomfort, stop using the product and speak to your pharmacist or dentist. They can advise whether an alternative product would be more suitable for your needs.

Can Colgate Peroxyl Mouthwash Interact With Other Medicines?

No clinically significant drug interactions have been identified for hydrogen peroxide at the 1.5% concentration used in this product. Because it is used as a mouth rinse and spat out rather than swallowed, systemic absorption is negligible, which greatly reduces the potential for interactions with medicines taken orally or otherwise.

As a general precaution, avoid using Colgate Peroxyl at the same time as other oral rinses unless specifically advised to do so by a dental professional. If you are using a prescribed mouthwash alongside this product, check with your dentist or pharmacist that it is safe to use both.

If you are concerned about any side effects, contact your pharmacist or GP immediately.

Patient Information Leaflet

Important - Before taking any medication, it is always important to read the Patient Information Leaflet (PIL)

Written and reviewed by our qualified team

GPhC Number: 2233073
Tarun Kumar

Reviewed by:

Tarun Kumar

Superintendent/ Clinical Lead

📖 Find out more about our team of medical content authors and how we ensure the accuracy of our content with our content guidelines.

Content last updated: 31 Mar 2025

We’re a safe and
regulated UK service

Registered Pharmacy Badge

Lowest Price Guarantee

We're convinced you won't find your treatment cheaper, but if you do we'll refund the difference.

Find out more

100% discreet packaging

We're convinced you won't find your treatment cheaper, but if you do we'll refund the difference.

Find out more

Agent

Need help?
Talk to our friendly experts now

How our service works

Service Setup

Service setup

Discreet Packaging

Discreet packaging

Express Delivery

Express delivery