How Does Hair Dye Damage Hair? All Revealed


You’ve undoubtedly read about the horrors of hair dyeing on the internet, and wondered if it’s all true.

The answer is…yes, it can definitely damage your hair if you’re not careful!

In this blog post, I’ll discuss the topic “How does hair dye damage hair?” All revealed.

I’ll also share with you about the science of hair dye, and what kind of hair damage it can cause.

So read on to learn more!

What hair coloring does to your hair?

Hair coloring, when used wrongly, can do serious damage to your hair.

Just think about it, there are about 5,000 different chemicals used in hair dyes.

Isn’t it logical that with such large amounts of chemicals, there is a good chance some may end up damaging your hair!

Basic structure of hair

The hair consists of three layers: the cuticle, cortex and medulla.

  • Cuticle: It is the outer layer that contains tightly packed cells.
  • Cortex: The pigment rich layer that gives your hair its color.
  • Medulla: This is a hollow core.

How hair dye works

When you use hair coloring, it’s the cortex that gets colored, not the root.

Hair dyes contain many chemicals, such as ammonia and peroxides.

It can strip away or add natural color pigments to the cortex.

Ammonia and peroxides help open the hair cuticle. This allows color to enter or be rooted out from the cortex.

At the same time, these chemicals applied in large amounts can also damage the hair shaft.

Both chemical processes can cause the hair to become dry, brittle and dull.

Also, the hair can become porous, allowing the color to fade quickly.

  • Permanent hair color dyes – it has more ammonia and peroxides than temporary hair dyes.

This is because permanent hair color dyes are designed to penetrate the cuticle and cortex of the hair shaft.

While this may give you the hair color you want, the two chemicals can damage your hair.

  • Temporary hair dyes – unlike permanent hair dyes, it does not get as deep into the hair shaft. As a result, they are less likely to damage your hair.

Moreover, temporary hair dyes still contain harmful chemicals. So it’s important to read the labels before you buy them.

  • Semi permanent hair dyes – These dyes contain aromatic amines causing hair shaft swelling.

This allows the dye to penetrate the cuticle and enter the cortex.

They can irritate sensitive skin if you use them incorrectly.

Otherwise, they do not contain bleach and are less likely to damage your hair compared to permanent hair dyes.

Finally, semi-permanent dyes do not alter the natural color of your hair. Instead, they provide a layer of color outside. Due to this, it fades with each washing.

Ammonia-free dyes can lift your cuticles

The ammonia-free hair dyes are less harmful to your hair than the traditional hair dyes.

However, this does not mean they are completely harmless. The ammonia-free dyes still have other chemicals that can damage your hair.

How does hydrogen peroxide work?

The main chemical in both traditional and ammonia-free dyes is hydrogen peroxide. This chemical can lift your cuticles to start the process of coloring your hair.

Some ammonia-free dyes use monoethanolamine as a colorant as an alternative to hydrogen peroxide.

Studies done on both chemicals claimed it could cause hair loss and dermatitis.

Ammonia-free dyes can cause damage

Additionally, ammonia-free dyes may cause your hair to be darker than traditional dyes. This is because the lack of ammonia may prevent the color from penetrating as deeply into the shaft hair.

So, while ammonia-free dyes are less harmful to your hair, they still have the potential to damage it.

Alternatives are less damaging and do not last

If you want to try a color that is not permanent, you can use a semi-permanent or demi-permanent dye.

Semi-permanent hair dyes don’t contain peroxide. But demi-permanent dyes only contain low levels of peroxide.

Both these colors are less damaging, therefore they are a good option. Also, these dyes will last through a few shampoos, before fading after washing out.

What are the side effects of hair color?

The most common side effect of hair color is scalp irritation. This happens if the hair color comes into contact with your skin.

Furthermore, it can occur if you have an allergy to one of the ingredients in the hair dye.

Can dyeing your hair cause hair loss?

Another side effect caused by hair dye is hair loss. This happens when an ingredient in hair color, called para-phenylenediamine, enters your bloodstream.

This chemical can cause an allergic reaction that leads to hair loss.

Does hair dye cause cancer?

Hair dye may be the cause of cancer, such as leukemia and lymphoma.

In fact, researchers have been studying this link for many years. But all the evidence is still unclear.

The possible causes of cancer could be due to long-term use of hair dyes. You may be interested to learn that new epidemiology studies have shown dyeing matches breast cancer risk.

Is it safe to color my hair while pregnant?

Pregnant women should avoid hair dye, because it can lead to complications during pregnancy and fetal health. Other possible negatives, including:

  • Loss of hair strength
  • Reduced hair thickness
  • Increased roughness in your hair follicles.

Hair dye is toxic to your hair and your health.

Hair dye is not only bad for your hair, it’s also can be bad for your health. The ingredients in hair dye can be toxic to your body, including the scalp.

So, how does hair dye affect your health in the long run? Let’s take a closer look.

What Are the Health Risks of Hair Dye?

The Environmental Working Group (EWG) warns us not to use hair color that contains coal tar.

The ingredients in coal tar contain aminophenol, diaminobenzene, and phenylenediamine. All highly toxic chemicals ingredients found in the manufacture of hair dyes.

More research is needed.

Coal tar is an industrial chemical derived from coal, classified as carcinogen. This is confirmed by the National Toxicology Program and International Agency for Research on Cancer.

Researchers haven’t yet established a strong link between hair color and cancer. Still, some studies have found an increased risk of bladder cancer in people who frequently use hair dyes.

Other studies have found that hair dye chemicals can penetrate through the skin. Equally important, it can also enter the bloodstream.

Unfortunately, most studies are inconclusive.

What’s the bottom line?

Some research suggests there may be a link between hair dyes and cancer. Nonetheless, more studies are needed to verify this.

If you want to be safe, avoid altogether hair dyes that contain coal tar.

However, if you do use hair dye, follow the instructions on the package. On top of that, do patch test first to ensure you don’t have an allergic reaction.

Does bleaching damage your hair?

The International Journal of Cosmetic Science published a bleaching study. It showed the bleaching effects on hair shaft.

They found bleaching hair causes protein loss and damage to the shaft of the hair.

Protein loss occurs because the bleach breaks down the disulfide bonds. This disulfide bonds hold together the keratin fibers in your hair.

Severe bleaching causes more problems

The study referred to found that the more severe the bleaching, the greater the protein loss.

Moreover, this protein loss comes from the hair’s cuticle, cortex, and matrix. Also, this loss leads to hair shaft damage.

This is because it weakens the hair fibers and makes them breakable.

So, if you’re thinking about bleaching your hair, use a good conditioner and shampoo to help minimize damage. And, if you bleach your hair, take extra care of it afterwards.

Is graphene hair dye better?

Graphene dye coats the hair and does not alter its structure.

This makes it a much gentler option for coloring hair. It is also effective at absorbing light, which gives hair its color.

Furthermore, it means it can render hair any shade of brown or black, without the harsh chemicals.

In addition to being gentle and effective, graphene hair dye also has some other great benefits.

For example, it is antistatic, which means it reduces frizz. It is also water-resistant, so it will last through several washes.

Overall, graphene hair dye seems like a much better option than traditional hair dye.

We need to do more research

This product is for the future, as more study on graphene hair color is necessary.

There are also some scalability and regulatory issues that need solving. But it is definitely a promising hair color option for the future!

Is vegetable hair dye safe?

Henna is a ‘natural”, vegetable based semi permanent hair color. “Natural” does not imply the damage is any less severe, though.

According to a 2019 study, henna dyes can harm your hair and cause it to be coarser and brittle. When henna dye is left longer than an hour, the damage was comparable to bleaching. Moreover, there are possibilities it may cause dermatitis and skin irritation.

How can I repair my damaged hair?

If your hair is already damaged, there are a few things you can do to repair it.

Firstly, use a protein treatment. This will help rebuild the hair cuticle and improve elasticity.

You can do this at home with an egg or mayonnaise mask, or buy a commercial protein treatment from the store.

Secondly, get regular trims. This will help overcome any split ends and prevent further damage.

Finally, use a deep conditioning treatment once a week. This will help hydrate and protect your hair from future damage.

By following these steps, you can help repair and prevent further damage.



Coloring your hair can be a fun and easy way to change your look. At the same time, it is important to be aware of the potential damage that hair dye can cause.

By understanding how hair dye works and what it does to your hair, you can help minimize the damage and keep your hair looking its best.

My best advice is to do your own research.

Research everything from products, applications, side effects, etc before making a final decision.

Do you dye your hair? What tips do you have for keeping your hair healthy?

Let us know in the comments below!

Disclosure: Just a heads up: My articles may include affiliate links! If you buy something after clicking one of those links, you will not pay any extra money, but I will get a small commission. Many thanks for your support!

Disclaimer: We do not recommend or encourage you to use any of these statements as a substitute for professional medical advice, diagnosis, or treatment. They are for educational purposes only. The FDA has not conducted any studies on them. If you have a medical concern, see your doctor immediately.

Please follow and like us:
Follow by Email
Visit Us
Follow Me