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Colgate Peroxyl Mouthwash Review

Medically Reviewed By: Dr. Gemma Wheeler

(GDC Number: 259369)

Colgate Peroxyl Mouthwash Review

Colgate are one of the big brands within the dentistry and oral healthcare market and a name you have likely heard of.

From toothpastes to brushes, Colgate Peroxyl Mouthwash is from the company’s professional range of products and is not likely to be a mouthwash you see on the shop shelves all too often.

Preview Product Rating Price
Colgate Peroxyl Mouthwash Colgate Peroxyl Mouthwash 1,007 Reviews £4.79 £4.20

This is a medicated mouthwash that is designed to relieve minor mouth and gum irritations.

Your dentist or pharmacist may have recommended this or perhaps you are looking for something to help you relieve the pain in your gums.  In this full Colgate Peroxyl Mouthwash review we will give you all the information you wish to know, but before we get to the full written review, a few bits of key information are provided first.

For a more detailed comparison of choices and to learn more about mouthwash, see our best mouthwash post.

Does it actually work?

Yes, I found that the irritation subsided after use.

How much does it cost?

Whilst the exact price will vary depending upon where you purchase the bottle of Colgate Peroxyl from, the good news is it is not all that expensive and the prices are fairly stable.

The recommended retail price (RRP) is £4.79 here in the UK and typically the prices I found, primarily online ranged from £4.50 though to £4.70 so only 20p difference between the cheaper and more expensive outlets.

Coming in one size only the bottle contains 300ml of the hydrogen peroxide based mouthwash.


Where can I buy it?

Peroxyl is not a typical off the shelf mouthwash and is one you are likely to be recommended to by your dentist or healthcare professional.  You may find it on some shop shelves like Boots and Superdrug in the UK but you may find it easier to source online or at the pharmacy.


  • Antibacterial
  • Does what it should
  • Well priced given its more niche appeal
  • Nice flavour
  • Good shelf life


  • More expensive than some every-day (but less specialised) mouthwashes
  • Not an off the shelf product
  • Cap for measuring the dosage is not all that practical

Would I recommend it?

Yes, based on my usage I have no reason not to recommend it as a product for helping to deal with irritated mouth and gums.

Full Review

Your mouth is a gateway for germs and bacteria.  It is therefore important to assist your body’s natural defences by keeping your teeth and gums clean and in a good state of health so that you feel better.

If you do not take care of your teeth and gums, or perhaps if you feel ill or a little worse off, it is amazing what a quick freshen up can do for you.

We have lapses in our oral regime, or for whatever reason we may get a mild irritation to the mouth and gums, perhaps some swelling and abrasion or bacteria build up in the mouth.

Colgate Peroxyl is a specially medicated mouthwash that relieves minor mouth and gum irritations using a mix of ingredients, but primarily benefiting from the use of hydrogen peroxide to alleviate the soreness and irritation in the mouth

This is not a daily mouthwash and one to be used normally.  but you may be advised by a dentist to use this mouthwash, typically for a period of no more than 7 days.

So, what is it really like to use?


How I tested the mouthwash

Due to the type of mouthwash this is and the recommended usage time, I only tested this for a period of 7 days and this is not an extended trial of Colgate Peroxyl.

Official guidance is to use up to 3 times a day for no longer than 7 days and this is how I used it.

  • In the morning, soon after (but not immediately after) having cleaned my teeth
  • At lunchtime having eaten
  • At night, soon after (but not immediately after) having cleaned my teeth

Each time I used the recommended 10ml dosage.

When you choose to use it will be up to you unless your dentist advises a specific time or regularity for your particular circumstances. Popular advice is to use after eating.

Alongside this my normal tooth brushing pattern remained, cleaning my teeth twice a day for 2 minutes with an Oral-B electric toothbrush, the Pro 6000 set to daily clean mode, with a CrossAction brush head.

I mention in the bullet points above about not rinsing immediately after brushing my teeth; generally speaking it is advised to use mouthwash some considerable time after brushing your teeth, as by using immediately after cleaning your teeth can wash away much of the benefit brought about by the toothpaste and the act of cleaning.  Thus many, including the NHS advise using mouthwash at a different time.


Summary How I tested the mouthwash

  • Test lasted for 1 week (7 days)
  • Used at 3 different times of the day
  • Used 10ml each time
  • Used Oral-B Pro 6000 with CrossAction brush head
  • Cleaned twice a day for 2 minutes each time
  • Flossed once a day
  • No changes in diet

Daily Usage

If you are looking for a mouthwash that will simply clean away bacteria, leave your mouth feeling fresh and can be used everyday, then Colgate Peroxyl is not for you.

Yes, it removes bacteria, yes it leaves your mouth feeling fresh, but it is not designed to be used everyday.

This is because of the ingredients within it, the main one being hydrogen peroxide.

This is a chemical compound that is used in bleaching and disinfectants. Do not be put off, it is perfectly safe as an oral antiseptic cleanser or mouthwash as it is in a much smaller dose.

However it should not be over-used and it is advised to cease using this mouthwash after 7 days irrespective of whether there has been an improvement in the oral health or not.

Colgate Peroxyl looks to target and treat irritations within the mouth.  This could be split or bleeding gums, ulcers and more.

When used, the hydrogen peroxide within the liquid makes contact with peroxidases and catalases (essentially bad bacteria enzymes) present in tissues (gums) and saliva, which causes the rapid release of oxygen.

This reaction provides mechanical cleansing which flushes out mouth debris.

It also helps to facilitate healing and alleviates discomfort caused by minor mouth and gum irritations, such as aphthous ulcers, pericoronitis and trauma from fixed orthodontic braces.

The chemical reaction is also antibacterial in itself. This can help reduce the number of some types of bacteria in the mouth.


In its raw form hydrogen peroxide is extremely strong and is diluted within this mouthwash to just 1.5g per every 100ml, equivalent to 1.5%. This dilution is weak enough to be safe yet strong enough to be effective.

OK, so the ingredients are in place to work but what is it like to use?

The mouthwash itself is an aqua blue colour, not clear.  It has quite a strong smell to it if you put your nose in close to the bottle and to be honest you have to when it comes to taking your dosage.

When in the mouth though the taste is reasonably pleasant, certainly not bad (far better than many) but nor is it the best I have tasted. A mild flavour, it is not overpowering nor does it taste particularly medical in my opinion.

You can certainly feel the oxygen reaction as the result is a much frothier liquid when you come to spit it out.

The dosage is 10ml as is common amongst mouthwashes.

A 300ml bottle will get approximately 30 uses out of it.

As the advised usage time is 3 times a day for 7 days, 1 treatment will leave a little liquid in the bottom of a 300ml bottle.

If your dentist has advised differently, follow their advice.


As with any product ingested orally, should you notice any side effects stop using and seek further assistance. It perhaps goes without saying that if you are sensitive to hydrogen peroxide you should avoid this mouthwash.  It also contains levo-menthol which if accidentally ingested in excessive amounts may cause fits.

So do not swallow it – simply rinse it around the mouth for a minute and spit out.

If the mouthwash has not worked after 7 days and irritations persist, consult a dentist or medical professional as you may have a more serious condition requiring treatment.

Products like Corsodyl could be worth trying also as this targets the mouth and gums differently, but do be careful in the use of these following directions.

Children from the ages of 6-12 can use this but require adult supervision taking a similar or smaller dosage than an adult at 10ml.

At the time of testing I genuinely had a slight irritation to the mouth due to not feeling myself and generally being a bit run down.  Parts of my gums were a little inflamed and sensitive when brushed.

From the moment I began using this I felt some relief, but no sharp or sensitive pain or stinging sensation.  I was pleasantly surprised.

Corsodyl, a similar yet different product was much stronger and left quite a sour taste in the mouth. Chlorhexidine-containing mouthwashes, like Corsodyl, also have other negative side effects such as tooth staining and taste disturbances.

Peroxyl certainly left a freshness to the mouth, not quite as harsh as some and I could still taste the effects some 90 minutes later.


I did not notice nor have I seen others reporting of any common side effects like tooth staining, when using Peroxyl, so that is another positive here.

Unlike CB12 mouthwash that is a bit more statement than execution, the bottle used here by Colgate is functional and lacks shelf appeal.

Coming in 300ml bottles it is not small but not all that big and is a practical white colour with a slightly more colour rich label attached to it.

I think the good news here is that money has been spent on the product rather than the packaging.

The screw cap is a bit odd. Securing the bottle closed inside the cap from which you measure and drink the liquid is a taller tube.  It’s a bit small to try and pour the mouthwash into and then drink from. It does what it needs to, but when pouring you might need to concentrate.


Due to the limited time use of this product maybe this design is intentional? I think it could be better though.

Working out at anywhere between £4.50 and £4.70 per bottle Colgate Peroxyl is more expensive the more common everyday mouthwashes like Listerine but is more specialised so expect to pay a slight premium, although not a great one.

Each use cost about £0.15p.  For comparison’s sake, a conventional everyday mouthwash will work out at about 4-5p.

If this helps alleviate pain and saves a trip to the dentist, it could be a lot cheaper too!

Summary of Daily Usage

  • Aqua blue in colour
  • Froths quite a bit in the mouth
  • Mild taste to the mouthwash that was not overpowering although the smell can be
  • 1 x 10ml dosage rinsed and gargled in the mouth for a minute then spat out
  • Lid has a measure in for controlling dosage of mouthwash
  • The lid and measurement in the cap is a bit clunky and requires a bit of attention
  • 300ml bottle offers approximately 30 uses
  • 1 use can cost 15p or more

The Results

I can only speak from my experience with Colgate Peroxyl and my findings and results may well be different to yours.

I was actually suffering with a mild soreness and even light bleeding in the mouth at the time of testing (due to a few days poor routine and generally feeling run down) which allowed me to really experience the benefits during this testing period and it worked for me.

It improved the condition and within a couple of days my mouth felt healthier.

The irritation I felt may have been solved with returning to a good brushing routine, but I certainly found the pain was eased and soothed by the use of Peroxyl and probably sped the recovery process up by a day or two.

No side effects were experienced and the taste to me was ok.


Conclusion, is Colgate Peroxyl any good?

Yes, in my opinion it is.

This starts off from the fact that this is not a heavily marketed product, and is not widely available off the shelf.

A slightly strange viewpoint it might be, but sometimes if you have not seen or heard of it all that frequently means it is a little more specialised.  You have to go looking for it or specifically be advised about this until you know what it is, how well it works and where to get it from.

Whilst the dosage and extended use should ideally be advised by a dentist, unless you have any allergies or known reactions, there is little harm that can come from a week’s use.

It works differently to other medicated mouthwashes, such as Corsodyl, so it may be worthwhile trying such an alternative if you do not get on with Peroxyl.

Electric Teeth Rating

Colgate Peroxyl Mouthwash Review 1


  • Where can I buy Colgate Peroxyl?
    • You may find some Boots or Superdrug stores stocking this on the high street along with some pharmacists.  It may be a little easier to purchase online.  You can buy it from Amazon here.
  • What are the ingredients in Peroxyl?
    • Hydrogen Peroxide 1.5% w/v, Sorbitol 70% w/w (Non-Crystallising), Ethanol 96% v/v, Poloxamer 338, Polysorbate 20, Methyl Salicylate, Levo-Menthol, Sodium Saccharin, Brilliant Blue FCF (E133) and Purified Water
  • Does it contain fluoride?
    • No
  • Does it contain alcohol?
    • Yes, it contains 6% alcohol.
  • What does it taste like?
    • It has a mint flavour.
  • How often should I rinse?
    • It is advised to rinse no more than 3 times a day for a period no greater than 7 days.  For best effects use after eating and avoid use within half an hour of brushing.
  • Does it actually work?
    • Yes, I do believe so.  I felt and saw benefits as a results of using this. Individual conditions and circumstances will come into play.  Greater research sees few criticisms of this mouthwash.
  • Does it hurt?
    • I did not find it to do so. If you should gain additional sensitivity or side effects as a result of using it, stop doing so and consult a dentist.
  • How long does it last?
    • A 300ml bottle will last 30 uses of 10ml dosages or up to 10 days.
  • Can it prevent “morning breath”?
    • Colgate Peroxyl has not been designed to eliminate this but if used last thing at night you may find some benefit to the freshness of your breath come morning.
  • From what age can Colgate Peroxyl be first used?
    • 12 years old is the advised age without supervision from an adult.  Children aged 6-12 can use with adult supervision.
  • Can you water down the mouthwash?
    • Yes, although this may reduce the effects.
  • How should you use the mouthwash?
    • The advised directions for use are to rinse and gargle 10ml in the mouth for 1 minute, spit out and do not swallow.
  • Does Colgate Peroxyl stain the teeth?
    • No, it does not.
  • What is the shelf life of Colgate Peroxyl?
    • 24 months for the 300ml bottle. Do not use once the expiry date (printed on the bottle) has passed.
  • Who produces Colgate Peroxyl?
    • Peroxyl is marketed by Colgate-Palmolive (UK) Ltd, Guilford Business Park, Middleton Road, Guilford, Surrey, GU2 8JZ but is manufactured by BCM limited, Than Road, Nottingham, NG20 2PR.

About Jon Love

Jon is a leading voice on electric toothbrushes and has been quoted by mainstream media publications for his opinions and expertise.

Having handled & tested hundreds of products there really is very little he does not know about them.

Passionate about business and helping others, Jon has been involved in various online enterprises since the early 2000s.

After spending 12 years in consumer technology, it was in 2014 that he focused his attention on dental health, having experienced first-hand the challenge of choosing a new toothbrush.

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31 thoughts on “Colgate Peroxyl Mouthwash Review”

  1. Hello. My dentist prescribed 10ml Peroxyl rinse twice a day after a massive molar infection (I suffer from an aggressive form of congenital periodontitis and this happens very frequently). After a few days using Peroxyl, I suffered profuse bleeding from my mouth after brushing (with a lot of blood). Could this be a side effect of Peroxyl? I have to confess that I didn’t always spit out the mouthwash after 1 minute, I might have had it in my mouth for quite a bit longer than that. Thanks in advance.

  2. Hi I have just purchased this item and notice that it is clear and not blue as I have had previously,is this normal? It does say on the bottle that it is a colourless liquid. Also after using for 7days how long should you wait before ever using it again. Thankyou

    • I believe since review the formula/liquid colour may have changed.

      It is best to speak to your dentist regarding the frequency of use. If you are having ongoing issues with sensitivity, inflammation etc you need to find out the cause and the best treatment.

    • It is not really designed for helping with toothache as such.

      If you have a toothache, there is often an underlying cause that will need treating.

      Subject to the cause, this may provide some relief by helping cleanse the mouth, but your best course of action is to see and dentist and determine the cause of the pain you have.

  3. This product has now been altered. No longer blue in colour and no longer frothy in the mouth. Not a patch on the old product and which you have reviewed. Just like any other mouthwash now but with a heavier price tag. I have used this product for many years but I will certainly be looking to change this as its nothing different now.

  4. Someone in the comments mentioned a funny sensation in the fillings after using this. I also had a strange sensation after using Peroxyl for a couple of days. If you do a Google search, Hydrogen Peroxide reacts with Mercury which is a component of amalgam (shiny) fillings. Further online searching showed that some suspect the filling might (a) start to leach or leak into the body, and (b) thin out the filling. The tingling feeling in my filling after using it is a dead give away

    So I need to confirm for myself and for the benefit of others, is the percentage of Hydrogen Peroxide in Peroxyl safe to use if you have amalgam fillings? It’s all online–Hydrogen Peroxide reacts with Mercury. And if there are suspicions that this might be hazardous to use with amalgam fillings, why is there no disclaimer on the bottle?

    • James,

      Apologies for the delay in reply to your comment, but I wanted to ensure I could offer a proper reply to your comment.

      I spoke to our in-house dentist Dr Gemma Wheeler, and her response is as follows:

      In a short answer, yes the percentage of peroxide in Colgate Peroxyl is safe to use if you have amalgam fillings.

      Colgate Peroxyl mouthwash contains 1.5% hydrogen peroxide and is typically recommended only for short periods. Colgate have information on the products, including studies into the benefits on their website. Colgate themselves do not list amalgam restorations as a contraindication to the use of their Peroxyl mouthwash because there is no known hazard to using the mouthwash if you have amalgam fillings.

      Hydrogen peroxide mouthwashes, such as Colgate Peroxyl, are oxygenating agents. This means that they essentially “bubble” to release small amounts of oxygen, and this is what makes them effective at cleaning. However, this can create a tingling sensation in the mouth regardless of whether or not you have metal fillings.

      Research relating to the effect of hydrogen peroxide on fillings is normally about bleaching products, but these are the same active ingredients as in the Colgate Peroxyl mouthwash, and so results are transferable.

      Hydrogen peroxide can react with metal fillings which causes the release of mercury. The amount of mercury released depends on:

      – The concentration of the hydrogen peroxide.
      – The silver content of the original fillings material.
      – How long the filling is exposed to the peroxide for.

      It is worth noting that over the course of a normal day some mercury can be released from amalgam fillings, and procedures such as replacing fillings also result in relatively high levels of mercury being released into the mouth.

      The percentage of hydrogen peroxide available in Colgate Peroxyl mouthwash is below the safety threshold legally available in the UK because of EU restrictions. These low doses of peroxide in Peroxyl mouthwash have no evidence that they damage tooth structure, and higher doses of hydrogen peroxide are actually used in dental bleaching products for cosmetic procedures.

      The level of mercury released when an amalgam filling reacts with hydrogen peroxide is low, even for the highest concentrations of peroxide (i.e. 30%, compared to the 1.5% in Peroxyl mouthwash). The levels of mercury released are below those levels set by the World Health Organisation where levels of ion release is known to cause health problems.

      Because of this, I would say that Peroxyl Mouthwash is safe to use if you have metal fillings.

      If you still have concerns you may want to consider limiting the length of time you use the mouthwash to just a few days at a time. Alternatively, you may wish to switch to an alternative mouthwash without these known effects.

      Reference articles:

      Al-Salehi, et al. 2006. The effect of hydrogen peroxide concentration on metal ion release from dental amalgam. Journal of Dentistry. 35: 172-176

      Tredwin et al. 2006. Hydrogen peroxide tooth-whitening (bleaching) products: Review of adverse effects and safety issues. British Dental Journal. 200: 371–376

      Patel et al. 2010. Clinical use of hydrogen peroxide in surgery and dentistry – why is there a safety issue? British Dental Journal. 208:61–64

      El-Murr et al. 2011. Effects of External Bleaching on Restorative Materials: A Review. Journal of the Canadian Dental Association. 77: b59

      Yua et al. 2015. Effects of bleaching agents on dental restorative materials: A review of the literature and recommendation to dental practitioners and researchers. Journal of Dental Sciences. 10: 345-351


    • This is not a key selling point or feature of this mouthwash according to Colgate.

      Although it is designed to refresh and I suppose in some respects balance the PH levels in the mouth. But ultimately it is designed to relieve minor mouth and gum irritations. When peroxyl comes into contact with mouth tissue, oxygen is released in a bubbling action, flushing out debris, killing germs and helping to prevent infection.

  5. Has anyone received any side effects like I have? I may be allergic to the ingredients, but only used once a day for 5/6 days. My tongue turned a pale colour, then over a course of 4 days my mouth (esp the tongue and roof of mouth) became very sore and my taste buds began to scrape off. This left my tongue sore, incredibly red and found it difficult to eat. During this time my diet or lifestyle had not change apart from introducing the mouthwash. It has now been 2 weeks since using the mouth wah. My tongue is no longer sore, but have now developed patchy white tastebuds. Anyone know what I’m experiencing?

    • Yes I have had a similar experience. I mentioned it to my hygienist and she said she experienced the same herself. Like a shedding of the skin on the inside of the mouth. Also I found made one of my metal fillings feel strange. She told me if I just make sure to clean properly between the teeth with the brushes that should suffice.

  6. The directions don’t say anything about rinsing out with water after rinsing with the Peroxyl. Do you think that means after you swish the Peroxyl around for 1-2 minutes that you’re supposed to just spit it out and leave the peroxyl residue and film in your mouth. I would rather rinse it out with water to avoid the accidental ingestion of the chemicals if you get my drift. What do you think?

    • Ken,

      You should spit out as much excess as you can. Do not then rinse, doing so will wash away any good the mouthwash is doing/left behind. The very small residue left behind will not do you any harm.

  7. Thank you for the review. I would add that the frothing action of Peroxyl persists for a while after spitting out the mouthwash, which I found unpleasant and necessitated spitting several times to avoid swallowing it, which is not recommended. As I have periodontal disease I was advised by my dentist to use Peroxyl for 2 weeks alternating with Corsodyl for 2 weeks. I have found that this regime causes heavy staining of the tongue and eventually peeling skin on my tongue. I am not sure whether this is caused by combined use as I had used Corsodyl before without the peeling tongue. Both products do state on the bottle that they cause staining of teeth and tongue. My periodontal disease is now under control and I have thankfully been able to switch to a fluoride mouthwash. I hope this information will prove useful to others.

    • Hi Diana,

      Thanks very much for the comment, it’s always useful to hear the experiences people have had with these products. We’re glad to hear your periodontal disease is under control and no doubt the info you have provided will be useful to others considering these two mouthwashes.

    • Do you suffer from receding gums? I have periodontal disease and my gums are receding, have you noticed that this mouth wash helps with that? I just started using this tonight and I hope it will help with my receding gums as well.

      • Hi Lisa, Yes I do have receding gums and I am afraid that once they have receded there does not seem to be anything that can be done. The mouthwash is mainly to help with mouth irritation such as mouth ulcers, etc. The Corsodyl is to treat and prevent bleeding gums. The best thing you can do is to see a specialist in periodontal disease. I was told that part of my problem is bone loss in my jaw caused by years of smoking, although I gave up 10 years ago! I also have to have regular deep cleaning, every 3 months.

  8. Hi Jon,
    Excellent review, I too was recommended Peroxyl by my hygienist as Corsydyl stains the teeth. I fully agree with your findings however may I add that for me I found the texture quite slimy in the mouth. Not unduly unpleasant but quite strange . I have never used this product before and I must admit I used straight after cleaning my teeth – not surprisingly the benefit of Sensodyne toothpaste was lost. I will certainly wait now before rinsing with Peroxyl ……

  9. Thank you for the above info. I was recommended by my hygienist to use this product by dipping in my inter dental brushes in it. I found it very good as well but failed to ask if I should stop using after 7 days… Will check about that. I don’t actually use it as a mouthwash more in between the teeth brushing. Big improvement on my last visit so hope to keep using.

    • Hi Kate. I would imagine the dipping the brushes into it is to help reduce the change of problems in between your teeth and gums and the light coating on the brushing then helps alleviates any issues and acts a bit of a lubricant. I would suggest you could use for a lot longer as such a small amount would be applied to the mouth and only in between teeth rather than all over them. However over time it might not be advisable to keep repeating this. Perhaps speak to your hygienist to clarify. Do let us know.

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