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Writer's pictureDavid Chen, DDS

Purple Toothpaste Doesn't Whiten Teeth But Stains It Gray

Updated: Jan 16

The truth is, purple toothpaste doesn't work in whitening your teeth because it actually stains it into a gray color instead. You don't believe us? We've a couple of experiments for you to try at home which should convince you otherwise.


Hismile V34 colour corrector - box next to bottle

To be clear, we do think this is a fun product and the idea behind it is interesting but it just doesn't quite deliver as promised. But for the record, I do wholeheartedly believe that Hismile is a very innovative company and I love what they do with their PAP+ products.


Table of contents:


Purple toothpaste doesn't contain whitening agents

The primary reason why purple toothpaste doesn't whiten your teeth is because it doesn't contain any bleaching agents in its ingredients.


Directions & ingredients back of bottle
Hismile V34 colour corrector - back of bottle directions and ingredients

All teeth whitening products will have hydrogen peroxide, carbamide peroxide, or some derivative of it. When I say derivative, I'm looking right at you PAP whitening.


16% peroxide whitening
16% peroxide whitening

The purple toothpaste on the other hand does not have that and only contains a purple dye which is supposed to "whiten" your teeth. What you'll find on the label is a red dye and blue dye, which when mixed together produces the color purple.


whitening strips with peroxide
whitening strips with peroxide

Reason: Purple is not a primary color so it is created by mixing primary colors red & blue.

In summary, there is no chemical bleaching agent in this toothpaste, there is only a purple dye and that is the reason why it won't whiten your dentition.


It was never labeled as a tooth whitening product

If you read the label carefully for one of the most popular purple toothpastes, Hismile v34 colour corrector, it's not labeled as a teeth whitener. Both on the box and on the bottle, it explicitly says that it is for teeth "brightening" and not "whitening."


Hismile V34 colour corrector - on kitchen counter

If you look at their website, there is absolutely no mention of "teeth whitening" but what you will see is "teeth brightening." They are extremely careful with their wording most likely due to legal and liability reasons.


Yellow mixed with purple turns brown

The idea behind how the purple whitens your teeth is that yellow and purple are complementary colors which cancel each other out. Yes, based on color theory, these two colors can neutralize one another.


However, did you know that when you mix yellow with purple you get BROWN? In case you forgot about your art class days back in elementary school... Below is a video demonstration of how mixing equal amounts of yellow and purple results in a brown color.



Of course that is with yellow paint and purple paint but what happens when you use purple toothpaste instead? Below is a video showing purple toothpaste mixed with yellow paint.



Key points of experiment:

  • Yellow mixed with purple resulted in brown.

  • Yellow mixed with purple toothpaste resulted in brown/dark green/olive color.


Isn't that absolutely fascinating and does it make you even more curious as to whether the purple colored toothpaste even works?


 

Purple dye can reduce yellow tones

Despite everything we said about purple and yellow making brown, purple dye can in fact reduce yellow tones. To be more precise, small quantities of purple mixed with a lot of yellow will neutralize some of the yellow to produce a gray color.


Below is a video demonstration of how mixing a tiny bit of purple into yellow buttercream, which can neutralize yellow tones.



Note: At around 1:35 in the video she explicitly says if you add TOO MUCH purple, you'll end up with gray buttercream.


Aside from baking, purple dye can also reduce yellow tones for yellow hair. Below is a video demonstrating how purple shampoo can make yellow hair less yellow.



Summary recap:

  • Equal amounts of purple and yellow will make brown.

  • Small amounts of purple with large amounts of yellow will make gray.

  • Key point - the ratio of the quantity of colors being mixed will affect the color.


How purple toothpaste brightens teeth

Purple toothpaste works in reducing the yellowness of your teeth by temporarily staining the enamel surface with a purple dye.


How it works:

  • Purple toothpaste stains enamel surface with a purple dye.

  • The purple neutralizes some of the yellow due to complementary color theory.

  • The results are temporary because the purple dye will wash off upon eating, drinking, or brushing.


Stains teeth

There is no chemical bleaching agent in purple toothpaste, how it works is by literally applying a purple stain onto your enamel. Yes, under normal circumstances, any type of tooth stain is considered a bad thing but the combination of purple and yellow can reduce the intensity of yellow.


Complementary color theory

According to color theory, complementary colors that are opposite one another on the color wheel can cancel each other other.


color wheel
Credit: Proven winners

That means when you start mixing purple into yellow, it will start to neutralize it into a grayish color. It's not white but gray. That is another reason why it isn't listed as a whitening product but a "brightening" product. Although technically it is a graying product!


complementary colors on color wheel
Credit: Proven winners

Temporary results

The thin layer of purple stain on the enamel is not permanent because it will wash off once you eat, drink, or brush your teeth. In other words, the yellow reduction is only temporary in nature.


However, we will say that if you use this product long term, the stains can potentially become permanent. The idea is similar to how drinking coffee once won't stain your teeth but consistent consumption of it will eventually turn them yellow.


 

Pros & Cons


Pros:

  • Purple color is cool and trendy.

  • Immediate brightening effect.

  • Unique application of color theory.


Cons:

  • Cost more than traditional whitening toothpaste.

  • Brightening effect is temporary.

  • Can permanently stain teeth.

  • Makes future whitening more difficult.

  • Doesn't work on non-yellow teeth.


Major disadvantageswhitening toothpaste


Not all discolored teeth are yellow

The purple toothpaste can reduce yellow tones but not all teeth are actually "yellow" in color.


Natural tooth shade guide by VITA
Natural tooth shade guide by VITA

The image above is a tooth shade guide showing all of the colors that teeth naturally come in. Yes, most people would say that the darker shades are "yellow" but technically teeth can be red, yellow, and gray in color.



Teeth colors are categorized into four different shades or colors.

  • The A shades have a reddish-brownish tooth color.

  • The B shades have a reddish-yellowish tooth color.

  • The C shades have a grayish tooth color.

  • The D shades have a reddish-grayish tooth color.


vita classical shade guide instructions

If your teeth has a B1, B2, B3, or B4 tooth shade, the purple toothpaste can work in reducing the yellowness. But, if your teeth is in the A, C, or D shade family, you're completely out of luck because the purple dentifrice will NOT work for your teeth.


Note: If you see youtube videos or reviews about how the purple toothpaste didn't work for them, it's probably because their teeth isn't B colored...


Complicates future teeth whitening

Long term use of purple toothpaste may result in the purple dye permanently staining your teeth. The consequence for that is that it makes teeth whitening with peroxide more complicated and difficult in the future.


Reasons it becomes more difficult:

  • Yellow teeth have yellow stains in the enamel.

  • Using purple toothpaste will embed purple stains into the enamel.

  • Now you have yellow stains plus purple stains.

  • When you whiten teeth with peroxide, it has to oxidize both the yellow and purple stains.


Ultimately, the peroxide now has to do double the work because it has to bleach the yellow stains out of the enamel and the purple stains as well.


With that being said, if you're using this once in awhile, I do not think this is a cause for concern at all. You should go ahead and have some fun in your life.


Verdict - Does purple toothpaste work?

Purple toothpaste doesn't work in whitening your teeth in the way you think it does because it doesn't contain any bleaching ingredients. However, it can temporarily give you the illusion of brighter teeth since it stains your enamel with a purple dye that can reduce yellow tones.


In our opinion, we prefer the Hismile PAP+ whitening toothpaste over the purple toothpaste. Our recommendation would be to focus on the PAP toothpaste instead if you want better results. Although if you wanted to spice up your oral care routine, you can definitely give this a try. It is safe to use and relatively harmless!


That is all that our dentists in Long Island City have to say about purple toothpaste.

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David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

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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.

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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.

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

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