“Hair Color Oxidation: Hidden Damage or Secret Shine?

Last updated on April 12th, 2025 at 12:58 pm

Hair coloring has become a popular way to express individuality and style. Still, there is a culprit that destroys your vibrant shade, and many of us love to experiment with bold colors. However, sun exposure and prolonged exposure to the elements can cause an oxidation problem that leads to fading and damage.

This issue can make your beloved hair color lose its vibrancy, requiring it to be restored by your hairstylist. Knowing how to prevent this can save you from future headaches and help your color last longer.

The Science of Hair Color Oxidation

Hair color oxidation is a chemical process where the hair’s natural color or applied dye changes due to exposure to oxygen in the air. This causes the hair to lighten and sometimes leads to fading or irregular color alterations. 

 Over time, this oxidation process can lead to fading and irregular color alterations. When exposed to air or external oxidizers like UV light or chemicals, such as chlorine and bromine found in pools, the melanin structure in the hair gets disrupted. This can lead to a loss of pigment, leaving the hair looking lighter or with unwanted reddish undertones.

Sun exposure and UV rays play a significant role in this oxidation, especially on colored hair. Sun-kissed effects are common, but prolonged exposure without proper protection can accelerate the aging process of hair.

The outer layer of the hair shaft may begin to break down, resulting in peeling and discoloration, like unwanted green color pigments due to red color deposits in the presence of chlorine. Maintaining hair wellness requires careful attention to these environmental and chemical treatments.

How External Factors Contributing to Hair Color Oxidation?

1. Environmental Factors

Sunlight (UV radiation)

Sunlight, specifically UV (ultraviolet) radiation, is essential to break down artificial hair dyes, contributing to hair color oxidation. Hair dye, both permanent and semi-permanent, alters the chemical structure of the hair’s natural melanin and coats the hair shaft with synthetic pigments. However, these artificial dyes can also be affected by sunlight. UV radiation accelerates the process of color fading or oxidation in the dye molecules.

These hair dyes become less stable as compared to natural hair melanin structure. UV rays can cause the pigments of hair color to break down, leading to color fading and oxidation.  

This involves the loss of electrons from the pigment molecules due to the UV exposure. This electron loss destabilizes the pigment molecules, causing them to break down and lose their color intensity. Which eventually lead to color fading, often resulting in a washed-out, brassy, or dull appearance.

Exposure to Free radicals and pollutants

Color-treated hair exposed to pollution for a long time can suffer from free radicals, which accelerate oxidation. These generated reactive oxygen species (ROS) are highly unstable oxygen-containing molecules produced by pollutants like smoke, dust, and chemicals, which react with hair pigments, breaking down their composition. This oxidative stress damage leads to fading, dullness, and color loss, especially in chemically treated or porous hair.

Humidity And Moisture

Humidity can cause hair cuticles to swell and lift. This increases the hair’s exposure to environmental factors, as discussed above. When hair is more porous, it is more susceptible to oxidation, which causes hair color to fade or change.

The increased moisture can also weaken the hair shaft, leading to color molecules breaking down more quickly. As a result, the color-treated hair loses its vibrancy and can appear dull or brassy over time.

2. Chemical Exposure

Chlorine in swimming pools

Chlorine or Bromine is commonly used in swimming pools to disinfect the water and kill bacteria. These are two major oxidizers that can cause damage to your hair color and hair strands in various ways. Long time exposure without proper protection causes color fading, dandruff, and itchy scalp.

Hard water minerals (e.g., calcium, magnesium)

Hard water is also an enemy of your stylish and vibrant color. It contains minerals like calcium, magnesium, and copper, as well as salts. These minerals possess a positive charge and can accumulate on your hair over time, creating a plastic-like film that may dull the hair and make it look lifeless. 

Related: Oxidative Vs Non-oxidative Hair Color? Why Different?

3. Heat Styling Tool

When hair is exposed to high heat because of hairstyling tools, the cuticle can become damaged or lifted, making the hair more porous. This increased porosity allows moisture and chemicals to penetrate the hair shaft more readily and destabilize the hair color molecules.

Hair dye molecules are designed to stay stable at normal temperatures, but excessive heat can break them down. High temperatures can cause the oxidative dyes (used in permanent hair color) to degrade, leading to a loss of vibrancy and a shift in color tone.

4. Hair Care Products

Harsh shampoos and conditioners with Sulfates and Parabens

Parabens and Sulfates (like sodium lauryl sulfate or sodium laureth sulfate) and other harsh surfactants can strip away natural oils and moisture from your hair.  it becomes more porous and can oxidize the color molecules and lead to a shift in tone (e.g., warm tones turning brassy or cool tones fading to dull shades).

5. Hair Wash Frequency

It really matters as our experts always recommend washing your newly dyed hair less. Frequent hair washing will lead to faster color loss.

What are the Effects of Hair Color Oxidation on Hair?

1. Color Fading/ Patchy Appearance

One of the major aspects of hair color oxidation is the visible alternation of applied tone or, simply, color fading. Over time, you might face color fading due to any of the reasons I discussed above. Atmospheric oxygen reacts with the artificial pigment of hair, and the color appears dull and less vibrant. It will cause the blond or lighter shades to turn into brassy or warm tones like red or orange. 

Sometimes, the oxidation process does not affect the entire hair tone; rather, it appears inconsistent or patchy, with color fading depending upon the type of external exposure.

2. Structural Damage

As a hairstylist for over a decade, I’ve seen how chemical hair color affects the cuticle—the outer shield that protects your hair. Ammonia and hydrogen peroxide forcefully penetrate, breaking down the protein layers and keratin proteins that keep strands strong. 

This leaves the cortex (the inner core) exposed, making hair fragile and prone to breakage and even thinning. The shingle-like scales of the cuticle further open up and increase the strands’ porosity, causing lifeless, frizzy, and splity locks.

Oxidation strips away natural color, hair lipids, and essential proteins, weakening the hair shaft. The process also thins the cuticle layer, reducing shine, feel, and overall hair strength.

3. Impact on the Hair Cuticle

When your hair undergoes oxidation, it’s not just about color changes – it’s a destructive chemical process. I’ve seen countless clients surprised by how quickly their applied dye fades after extended sun exposure. Here’s why: UV rays and oxygen molecules in the air trigger a reaction that not only compromises your unique hair color but literally forces your cuticle layers apart.

A healthy hair cuticle has flat, overlapping layers of keratin that seal in moisture and protect the inner cortex. But during the oxidation process, three things happen:

1. Disulfide bonds in keratin disrupt, causing scales to lift and break off
2. Fatty acids and proteins degrade, making hair porous
3. The cuticle becomes missing or lifted, so the cortex absorbs and loses moisture rapidly

The result? Porous, dry, brittle hair that absorbs and loses moisture rapidly. Once the cuticles are lifted or missing, damage becomes harder to reverse.

4. Effect on Keratin and Protein Bonds

As we all know, Keratin, the primary structural protein in human hair, plays a crucial role in maintaining hair strength through disulfide bond crosslinks—both intra-molecular and inter-molecular. However, research shows that polysulfide bonds are also abundant in keratin and help regulate oxidative stress. These polysulfides naturally occur in hair, supporting homeostasis by acting as antioxidants.

Interestingly, hair defends itself against oxidative stress by distributing polysulfides across the cuticle surface. When treated hair is exposed to factors like UV exposure and styling heat without the necessary protection, it will significantly reduce these protective compounds (polysulfides).

Since polysulfide levels vary between individuals, some hair is more resilient than others. Ultimately, these bonds contribute not only to hair strength but also to cuticle attachment strength, proving essential for maintaining healthy hair under stress.

5. Moisture Loss and Dryness

Natural oils (like sebum in hair and skin) contain fatty acids that keep surfaces moisturized. Oxidation degrades these lipids, making them less effective at retaining moisture. Most permanent hair dyes use ammonia to open the hair cuticle and hydrogen peroxide to oxidize melanin (your natural pigment) and deposit new color. This process weakens the hair’s protective barrier. Long-term exposure to sunlight, heat, or chlorine water further worsens the situation and cause

• Loss of Moisture → Frizz, dullness, and split ends.
• Weakened Keratin → Hair becomes fragile and prone to breakage.
• Color-Treated Hair Fades Faster → Further accelerates dye molecule breakdown.

6. Weakening of Hair Strands

Hair color oxidation causes the hair to lighten and develop a reddish undertone due to the loss of pigment in the hair shaft. Over time, the outer layer of the hair shaft starts peeling away, leaving the cuticle, the outer protective layer of the hair, vulnerable. These overlapping cuticle scales no longer shield the inner cortex, exposing the hair to harm.

The use of chemical processes like bleaching, perms, and relaxers combined with frequent styling with heat tools such as flat irons and blow dryers intensifies oxidative stress on the hair. This leads to the cuticle being lifted and broken, allowing moisture to escape and leaving the inner cortex exposed and damaged.

Repeated oxidation, especially from bleach, breaks the disulfide bonds within the cortex, reducing hair’s elasticity and causing it to snap easily. 

How to Minimize the Negative Effects of Oxidation?

Pre-Coloring Care

To minimize the adverse effects of oxidation, it is highly recommended to incorporate deep conditioning treatments and keratin protein masks twice a week to strengthen hair. You can purchase it ready to use from the store or give a try to DIY. It helps to moisturize your cuticles and maintain their porosity.

Choosing the Right Products

Choosing the right product is always a game-changer. If you are planning to change your look, it is essential to discuss your ideas and desires with professional hair experts like those at Twisty Treasure. They give you expert level choices while selecting your color to post-care according to your budget as well as with less stress to your strands.  

Post-Coloring Maintenance

To keep the vibrancy of your blondes, it is good to stay away from parabens and sulfates as they accelerate the oxidation process and cause hair to lose its shine. Opt for shampoos and conditioner specifically for color-treated hair as they have mild surfactants and become less harsh to hair.

Professional vs. At-Home Coloring

At-home hair coloring seems to be cool as it is cost-effective and stays away from appointment schedules, but it is not a good idea for your hair. Although Box hair color packs are easy to use, they have a high concentration of ammonia in the formula, which causes severe hair damage. Secondly, you cannot know as much as a professional hair stylist about hair anatomy and current health status, and they treat your strands according to it so that you will get the desired color.

What are the Alternatives to Traditional Oxidative Hair Colors?

Natural Hair Dyes

When it comes to coloring your hair, many people are now turning to natural alternatives to avoid the harsh effects of chemical and artificial dyes. One of the great options is coffee, which darkens brown hair naturally, providing a safe and acceptable solution for those seeking to color their hair without using permanent dyes. 

Henna, another natural option, has been used for centuries. It contains a coloring ingredient called lawsone, a red-orange compound found in the dried leaves of the henna plant. This compound acts as a nonoxidizing agent and provides a gentle, natural way to change your hair’s color. Henna also includes other beneficial components like flavonoids and gallic acid, which serve as organic mordants, helping the color last longer. 

Non-Oxidative Hair Colors

Non-oxidative dyes, also known as direct or semi-permanent dyes, don’t require an oxidative chemical reaction or any oxidative agent like hydrogen peroxide to develop and fix the color. Instead, these dyes work by depositing pre-formed, ready-to-use pigments directly onto the hair shaft. They coat the cuticle without chemically altering the natural pigment.

These dyes provide a gentle, temporary solution for adding color and are perfect for experimenting with on special occasions or for a fun, festive look. Since they don’t penetrate the outer layer, they last only from one shampoo wash to a few days, depending on the product and hair type.

Conclusion

In conclusion, hair color oxidation is a chemical process that significantly alters the structure of hair, affecting both its appearance and health. The oxidation process not only alters your favourite tone to become darker but it can also weaken hair fibers and lead to dryness, brittleness, and breakage. Proper aftercare, such as using conditioning treatments and limiting heat styling, can mitigate these negative effects.

FAQs

What Happens When Hair Color Oxidizes?

Hair color oxidizes when exposed to sun, UV light, or chemicals, causing it to lighten and develop a reddish undertone due to loss of pigment from the hair shaft as the outer layer peels away. This process weakens the color and the overall structure of the hair.

Is Oxidation Bad for Hair?

The Oxidation process can cause hair to be impacted before it even emerges, contributing to premature hair loss. It also disrupts the color tone and vibrancy of your hair, leaving it looking lifeless and brittle. Over time, the damage becomes more noticeable and can affect the overall health of your hair.

Is Oxidizer Harmful to Hair?

While oxidizers act as a color fixer, using large amounts can cause serious damage. Over time, oxidizers can break down the hair’s structure, leading to deterioration and weakness. The hair also feels dry and fragile, gradually losing its strength.

How Does Hair Color Damage Your Hair?

Hair color can significantly impact the overall health of your hair by breaking down keratin molecules in the hair cortex. These essential proteins that form the structure of your hair get broken into smaller pieces with each color process, weakening the hair over time.