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Swishing Hydrogen Peroxide Can Whiten Your Teeth

Updated: Jan 30

Yes, swishing hydrogen peroxide can whiten your teeth because that is the same ingredient that is used in all teeth whitening products, both OTC and professional.

3% hydrogen peroxide in 32 oz bottle

Table of Contents:

All teeth whitening products whiten using peroxide

The whitening ingredient in ALL teeth whitening products whether they're OTC or professional, all use some form of peroxide. The two most commonly used types of peroxide for whitening teeth are hydrogen peroxide and carbamide peroxide.

crest 3d whitestrips use hydrogen peroxide
crest 3d whitestrips use hydrogen peroxide

Carbamide peroxide is a precursor to hydrogen peroxide because it takes an additional step to breakdown into it. This extra reaction step makes it more shelf-stable.

carbamide peroxide kor


The only exception would be whitening products that use PAP (Phthalimidoperoxycaproic acid) instead of hydrogen peroxide.

PAP whitening products
PAP whitening products

At least that is how PAP is marketed... Although in our opinion, it is still technically peroxide based since hydrogen peroxide is one of the base ingredients used to make PAP.

Whitening mouthwashes do contain hydrogen peroxide

Perhaps you may not have been aware of it but there are mouthwashes out there specifically meant for whitening your teeth. These whitening mouthwashes all contain varying concentrations of hydrogen peroxide (HP) and that is how they make your teeth less yellow.

colgate optic white 2% peroxide mouthwash
2% peroxide mouthwash

Examples of whitening mouth rinses that are peroxide based:

  • Colgate optic white whitening mouthwash (2% HP)

  • Crest pro-health advanced with extra whitening

Both of these mouthwashes are marketed as being able to whiten your teeth. They both contain peroxide with the Colgate having 2% while the Crest does not disclose the concentration.

How to swish with hydrogen peroxide to whiten teeth

  1. Pour 15 mL into cap.

  2. Swish and gargle for 60 seconds.

  3. Spit back out and do not swallow.

You can basically repeat the steps above twice a day for whiter teeth. You also must be 12 years or older to use this product as per Colgate.

Whitening mouthwash vs Hydrogen peroxide in a brown bottle

There is no difference between the "whitening mouthwashes" and the typical brown bottle of hydrogen peroxide. Peroxide is peroxide and nothing in the world will make it different. In other words, both types of mouth rinses should have identical effects.

peroxide in brown bottle

However we do want to point out that the brown bottle of HP actually contains a higher percentage of peroxide than whitening mouth rinses that are commercially available.

Concentration of peroxide in various mouthwashes:

  • Brown bottled peroxide has 3% HP

  • Colgate optic white has 2% HP

  • Crest extra whitening has undisclosed amount of HP

What makes it even more interesting is that the brown bottle of peroxide does not list teeth whitening as one of its uses on the label. Although it does possess the ability to brighten them.

First aid to help prevent the risk of infection in minor cuts, scrapes and burns - aids in the removal of phlegm, mucus, or other secretions associated with occasional sore mouth.

Isn't it absolutely fascinating that the more potent everyday product that is not listed as a bleaching product should be more effective than the actual whitening rinses?

Can a mouthwash with hydrogen peroxide whiten teeth?

As long as the product contains hydrogen peroxide, it will have a teeth whitening effect. Mouth rinses which contain HP will be able to make your teeth whiter because the mechanism for how it whitens remains the same.

Hydrogen peroxide is a powerful oxidizer of tooth stains because it can diffuse through the tooth while oxidizing intrinsic as well as extrinsic stains. That means it can bleach both types of teeth stains.

To go a little bit deeper in how that results in whiter teeth... it isn't the peroxide that directly bleaches your teeth. HP is actually very unstable and will naturally degrade into water, oxygen, and heat. However there are intermediary steps which produce free radicals (perhydroxyl) which are the true oxidizing or whitening agent.

Hydrogen peroxide degradation mechanism
Hydrogen peroxide degradation mechanism

The point that we want to make is that as long as the product contains peroxide, it will go through this same mechanism and it will produce the perhydroxyl radical. In other words your teeth will become whiter if you use a mouth rinse with HP.

Peroxide mouth rinse whitening efficacy

Despite us hounding you in the entire article that swishing with hydrogen peroxide can whiten your teeth, unfortunately it is not the most effective way to do it. There are inherent disadvantages to it if you're trying to bleach them via just swishing and gargling with HP.

Saliva impedes whitening efficacy

Saliva is the arch nemesis to all of teeth whitening because it contains salivary peroxidases. These are enzymes which break down peroxide in order to prevent our body from toxicity. Its purpose is to render hydrogen peroxide to become harmless.

That is actually one reason why in-office whitening at the dentist is so effective because they're able to isolate your teeth from saliva. If you recall, your dentist has a saliva ejector which suctions out saliva from your mouth. This reduces the amount of saliva in your mouth and helps to prevent it from coming into contact with the whitening gel.

When you whiten at home you often lose this benefit because you don't have a saliva suction. That in itself makes all at home products less effective than the professional in-office ones.

Last but not least, when you use hydrogen peroxide as a mouthwash and swish around with it you're purposefully exposing it to saliva. Then there is also the fact that you tend to salivate more while you're swishing and gargling with it. Due to the combination of all of these factors, it actually decreases the efficacy of whitening mouthwashes in general.

Rinsing duration is insufficient

Another often glazed over factor which renders peroxide mouth rinses less effective for whitening your teeth is the short rinsing duration. Most mouthwashes only require you to rinse for about 60 seconds before spitting it back out. If you were trying to whiten your teeth, that is a super short treatment time is it not?

You can compare it to professional in-office whitening which have you in the chair with the bleaching gel on your teeth for about 60 minutes. It'll all make sense if we lay it out for you.

Peroxide mouthwash:

  • Whiten for 60 seconds

  • 3% concentration of peroxide

  • No protection against saliva

In-office whitening procedure:

  • Whiten for 60 minutes

  • 35-40% concentration of peroxide

  • Saliva suction present

Essentially what makes this mouth rinse version of HP less effective is that it doesn't whiten your teeth for a long enough period of time. Studies have shown that lower concentration products can whiten teeth to the same level as higher concentration products but it simply requires a longer treatment time.

The way we use mouthwash goes against what we know about whitening. We should technically be rinsing with it for a longer period of time if we actually want to see results but we don't. No one really rinses for longer than a minute anyway.


Swishing with hydrogen peroxide will whiten your teeth because it is a legitimate whitening agent. In fact, it is the exact same ingredient that is used in all whitening products from pens to strips and even in-office professional treatments.

However it may not be as effective as you may think because saliva and also the short rinsing time hampers its results. It also wouldn't really whiten any fake teeth in your mouth.

Nonetheless, it is still a great adjunct to your armamentarium of keeping your teeth white. If your goal was to have bright white teeth, of course choosing a whitening mouthwash would be better than a non-whitening one. Therefore there is still a place for HP rinses.



David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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