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Do I Rinse After Whitening Strips?

Updated: Feb 1

After taking the whitening strips off you should rinse your mouth to remove all residual whitening gel so you don't swallow excessive amounts of it. Another reason is that the gels become inactive after the stated duration of time.

Crest 3d whitestrips
Crest 3d whitestrips

People may think that it is more beneficial to leave it on longer than instructed because it makes their teeth whiter but that is incorrect. We will explain why you should follow the manufacturer's instructions exactly as stated.

Table of Contents:


Minimize swallowing of whitening gel

You want to rinse after taking off the strips so that you minimize the amount of whitening gel that you swallow. Immediately after removing them there will be a lot of residual bleaching material on the surfaces of your enamel.

If you leave it as is without rinsing, you will end up ingesting all of it. That isn't the ideal course of action to take because the main bleaching ingredient in the strips is roughly 5-6% hydrogen peroxide.

Different brands of whitening strips:

  • Crest 3D whitestrips

  • Moon whitening strips

  • Rembrandt strips

  • Hismile pap+ strips

Hismile whitening strips

All of the strips and whitening products in general contain hydrogen peroxide because that is what they use to whiten your teeth. The purpose of the strips is to hold the gel against your teeth so that they stay put and work more effectively. That is basically how whitening strips work.

Hydrogen peroxide isn't exactly an ingredient that you put in food. It is not something that you want to purposefully swallow. Think about it, if you use a hydrogen peroxide mouth rinse do you swallow it or spit it back out? Hopefully it is the latter.

Therefore it is important to rinse out after finishing the treatment because you want to minimize the amount of whitening gel that you swallow.

Is hydrogen peroxide dangerous if you swallow it?

It is relatively safe even if you accidentally swallow some of the hydrogen peroxide because the concentration of the product is on the lower end. There is also the fact that your saliva has enzymes which break down the peroxide.

All OTC whitening products are of a much lower peroxide concentration than the in-office products provided by your dentist. This is so that you can whiten safely at home. At the dentist, they have a saliva ejector which suctions out residual gel during the treatment and that is what allows them to use a higher concentration product.

Your saliva naturally has salivary peroxidases which are enzymes that break the peroxide down so that you can swallow it uneventfully. It is a defense mechanism to prevent you from being intoxicated. Hydrogen peroxide actually just breaks down into water and oxygen which are both completely harmless.

Nonetheless the point that we want to make is why would you purposefully try to swallow it? Even if it is relatively safe, it isn't something that you would want to ingest since it provides no benefit to you for doing so.


Whitening gel inactivates after stated duration of time

There is a misconception that the longer you leave the whitening gel on the more effective it will be. Due to that misunderstanding some people may try to not rinse out so that the whitening gel can work longer.

That is not true because the whitening gel can not work indefinitely. There is a finite working time that the hydrogen peroxide has to exert its effect on your teeth. You don't have to guess how long that is because the manufacturers have already figured that out for you. The amount of time they say to use their product is approximately how long the gel will work on your teeth.

There are actually two reasons why the hydrogen peroxide stops working:

  • Enzymes in your saliva naturally inactivates the peroxide.

  • Hydrogen peroxide is very unstable and will naturally decompose on its own. It is very sensitive to light and heat. That is the reason why it typically comes in brown bottles!

Hopefully that is convincing enough for you to not try to keep the whitening gel on your teeth for longer than the stated duration of time. You should rinse your mouth out and thoroughly at that once you finish the treatment.


What to do after removing whitening strips

There are measures which you should take after removing the whitening strips because the whitening gel is fairly acidic since it is peroxide. In order to bleach your teeth you're essentially leaving acid against your tooth enamel.

What happens is that the acid will actually demineralize your enamel and make them sensitive. What you want to do is to minimize these effects and restore it to what it was before starting whitening.

This is a protocol for what you should do after finishing the treatment:

  1. Rinse out thoroughly to remove all residue. (A baking soda mouth rinse would be the most effective since it can neutralize acid).

  2. Wait 30 minutes for your mouth to deacidify.

  3. Brush your teeth for 2 minutes with a remineralizing toothpaste such as fluoride or nanohydroxyapatite.


The whitening gel is highly acidic and you don't want to use it for longer than what is necessary. The reason is because the acidity from the gel slowly demineralizes and softens the tooth enamel. Basically the teeth are in a weakened state immediately after finishing the whitening strip treatment.

You do want to rinse out immediately afterwards so that you get all residual acids off of your enamel. That way it doesn't continue to weaken your teeth.

Rinsing with plain water will do the job but if you really want to help your teeth you should rinse with a baking soda solution. Baking soda is very potent at neutralizing acid which is why it is often recommended by the ACOG to rinse with if you're pregnant with morning sickness. The baking soda mouthwash will prevent your enamel from acid erosion if you throw up a lot.

baking soda

How to make a baking soda mouth rinse:

  1. Fill one cup of water.

  2. Mix in 1 teaspoon of baking soda.

  3. Stir the mixture lightly.

  4. Rinse for about 60 seconds.

  5. Spit out.

Wait 30 minutes

The goal is to brush your teeth and remineralize the demineralized enamel but you don't want to do it immediately. You want to wait at least 30 minutes prior to brushing so that your mouth isn't in an acidic state.

Your mouth will naturally deacidify the environment all on its own but it requires at least 30 minutes to do so. If you brush too soon you will be rubbing the residual acids directly onto the already softened enamel.

Remineralizing toothpaste

One of the best ways to repair and restore your enamel is by brushing after using whitening strips. However you shouldn't just brush with any toothpaste because you want to use a remineralization toothpaste.

sensodyne toothpaste with sodium fluoride

These toothpastes can reverse the effects of the bleaching agent by adding minerals back into your teeth. All acids, including whitening gel will demineralize your teeth which takes minerals out of your enamel. These toothpastes essentially reverse the process so that your teeth can be restored to its original state.

There are only two types of toothpastes which can do this and they are fluoride and nano-hydroxyapatite based products. Either one is fine so choose whichever one you like! The latter does tend to be more costly since it is newer and not as well-known.



According to our dentists in Long Island City, it is advisable to rinse immediately after finishing whitening strips because there is no benefit to let the residual peroxide stay on your teeth. The whitening gel has most likely stopped working after the stated duration of time. It is not beneficial for you to leave it in your mouth and risk swallowing it.

FYI if you don't get the results you're looking for with OTC products, you should try professional teeth whitening.



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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