The mestiza muse

be beautiful. be natural. be you.

Hello There!

I'm Verna,
Your Curly-Haired Friend.

Curly hair is like a box of chocolates, you never know what you're going to get. It could be super-defined one day and a frizzy concoction the next day – and it's never exactly the same from one head to another. Our mission is to equip you with the necessary tools for restoring and maintaining healthy locks and celebrating the hair you were born with! 

Hair Photobleaching: How It Happens & How to Prevent It

May 15, 2023


Verna Meachum

Image of Black woman with back of hair facing the sun.

We only work with and promote products from companies that we trust and feel are good for our consumers to use. We are reader-supported. If you decide to make a purchase through one of our links, we may earn an affiliate commission. Please read our disclosure for more info.

follow @themestizamuse
Curl care

With extensive experience in the beauty industry, I specialize in writing for curly hair care brands, websites, and magazines.

Not only do I have curly hair, but my children, friends, family members, and even friends who are professional curly hairstylists, each with their unique curly textures.

 You get the point :) 

I also partner with a friend who holds a Ph.D. in chemistry and works as an R&D Chemist, ensuring our content is scientifically accurate and help us navigate through the misinformation around curly hair care. 

Hi,I'm Verna

product reviews

Prepare yourself for an unforgettable adventure and make sure to pack these essential items to take with you on your journey.

Great hair goes beyond using shampoos, conditioners, and styling products. Shop my favorite must-haves.

After years of requests, I'm finally sharing my go-to skincare products.

Give your space a quick refresh with these ultimate home decor ideas.



Last Updated on May 15, 2023 by Verna Meachum

Ah, summer! The time for beach trips, pool parties, and… hair photobleaching? That’s right, while you’re soaking up the sun and enjoying life, your hair might be silently screaming for help.

Hair photobleaching is the sneaky villain that causes your hair to lose its color and vibrancy when exposed to sunlight. But fear not, sun worshippers – we’ve got your back!

In this article, we’ll delve into the science of hair photobleaching, how it happens, and most importantly, how to prevent it.

What Exactly is Hair Photobleaching?

Image of Loose red hair in the sun for Hair Photobleaching: How It Happens & How to Prevent It blog.

Photobleaching refers to the process of using light radiation to lighten the color of human hair fibers. This process results in a bleached appearance and a lighter overall color tone.1-2

Hair color can change through photobleaching, which can be controlled or happen naturally. Controlled photobleaching can be used to alter the hair color shade, while natural photobleaching happens over time with repeated exposure to sunlight.

During the hot summer months, you may have noticed a change in the tone of your hair color. This is caused by the interaction of solar radiation with the fibers of your hair.

Which type of radiation causes more damage to hair color? Additionally, what are the other physical or chemical changes that occur during photobleaching and how do they affect hair health, its properties, and cosmetic appearance?

Let’s find out.

Melanin: Hair Coloring Pigment

Vector illustration - In cross section straight hair is round and curly is flatten. Black hair has mostly eumelanin, blonde has more pheomelanin. Grey hair has no pigment and has air in the medulla.

Hair color is due to melanin granules present inside the hair cortex (the same melanin that gives color to our skin). These gains are small sac-like structures lying inside the hair protein matrix.

The color of the hair fiber is created by melanin reflecting the visible light (400-800nm) in the solar electromagnetic spectrum. This means that the human eye can only perceive colors that are created through the reflection of visible light.3

To change hair color, two methods are commonly used: one involves bleaching the melanin using an alkaline hydrogen peroxide solution, while the other uses a light source emitting visible light radiation with a specific wavelength and energy to lighten the hair.

The energy of incoming light radiation must be high enough to break the chemical bonding of the melanin structure. This can be achieved by bombarding visible light radiation of a specific energy and bandwidth (wavelength) targeting melanin structure.2,4

In addition to bleaching melanin grains, exposure to solar radiation can cause other reactions. This is because solar radiation is made up of a mixture of different wavelengths and energy, including high-energy UV radiation that can damage hair proteins and lipids.5

Why Hair Photobleaching Happens

Human hair fibers get their color from a complex and large polymer called melanin. Two types of melanin contribute to hair color – Pheomelanin and Eumelanin.

These types have unique chemical structures, which lead to different color shades. Eumelanin is responsible for black and brown shades, while Pheomelanin imparts red to yellow shades in the hair.6 

The light from the sun penetrates the outermost layer of the hair, called the cuticle, and into the hair shaft. The protein in hair, called keratin, does not absorb this light, so it goes deep inside the hair fibers and is reflected by melanin grains.

Repeated and continuous exposure to solar radiation, including visible and UV light ranging from 200-800nm, can cause the breakdown and chemical degradation of melanin molecules. This results in a decrease in the overall concentration of melanin grains, causing a lightening of the hair color shade.

Under direct sunlight, two types of melanin exhibit different behaviors during photobleaching due to their varying chemical structures and response to UV and visible light. This chemical reaction is permanent and irreversible, resulting in a lighter hair color appearance, often with a more yellowish tint.

Why Is Hair Photobleaching Bad?

Image of side profile of curly haired woman outside in the sun wearing a black jacket.

Melanin, which gives color to our skin and hair, also acts as a natural antioxidant and protects our skin and hair from harmful UV radiation.

When hair is photobleached, the melanin grains are bleached as well, causing the hair to lose its natural antioxidant. This makes it susceptible to oxidation caused by high-energy UV radiation.

Numerous scientific studies have revealed that UV exposure can have detrimental effects on hair fibers.78 

The UV radiation in the range of 200 to 400 nanometers in the solar electromagnetic spectrum is capable of breaking the chemical bonds of keratin.

Exposure of hair fibers to UV irradiation has shown high amounts of cystic acid which is an oxidized product of cystine amino acids. This process makes the hair more hydrophilic, alters the electrostatic properties of the hair fiber, and increases hair porosity, leading to significant frizz. As a result, managing and styling photodamaged hair becomes challenging.

To put it simply, photobleaching can have adverse effects on your hair. It can make your hair weak, porous, and frizzy, with a dull appearance.

How to Prevent Photobleaching

To prevent photobleaching and protect hair from its harmful consequences, follow these basic steps.

● To avoid hair damage, it is important to limit its exposure to sunlight. The longer the exposure, the weaker the hair becomes. If you spend a lot of time outside, it is recommended to wear a hat to reduce the duration of exposure.

● There are two types of sunscreen agents – physical sunscreen agents and chemical sunscreen agents. In hair care, chemical sunscreen agents are typically preferred because they are easier to apply to hair shafts and can absorb UV radiation to protect the hair and minimize damage.

Leave-in conditioner containing a blend of natural oils (e.g. olive oil, apricot kernel oil, grapeseed oil, etc.) also offers good protection against UV radiation. These oils are rich in vitamin E which has an excellent profile in controlling the photo-induced damage to hair and skin.

● To protect against UV damage, look for hair care products that contain natural extracts, such as green tea extract. This extract contains polyphenols that can reduce the impact of UV radiation by neutralizing free radicals. When shopping for hair products, search for rinse-off or leave-in conditioners that contain these extracts.9-10 

Alternatives to Hair Photobleaching

To achieve the desired results when lightening hair color through photobleaching, certain important factors must be considered.

Firstly, only visible light should be used to prevent any damage to the hair fiber from UV rays.

Secondly, the bleaching process should specifically target melanin grains in the hair and should not oxidize the protein components of the hair structure. This can be achieved through visible light irradiation at a specific wavelength.

Melanin bleaching with alkaline hydrogen peroxide is a common method used to manage the negative effects and limitations of photobleaching.

Bleaching hair with alkaline hydrogen peroxide is a convenient and easy way for consumers to do it themselves at home or a salon. However, this process can weaken the hair structure and cause significant damage to the hair fibers.


Photobleaching is a process that uses light to lighten hair color and break down melanin granules. When exposed to sunlight, photobleaching can break down the structure of melanin, resulting in lighter hair color.

However, direct exposure to sunlight can cause photobleaching, which in turn can lead to the oxidation of keratin components, ultimately damaging the hair’s mechanical strength. To preserve the integrity of the hair fibers, it is recommended to limit your exposure to solar light.

Managing and styling hair fibers that have been damaged by exposure to light (photodamage) can be challenging.

One alternative method for lightening hair color is through the use of alkaline hydrogen peroxide. Regardless of which bleaching method is used, it is important to regularly condition, hydrate and moisturize hair fibers to ensure good quality, fiber health, and maintain a natural appearance.


1. Dunford, R. L. The photo-assisted bleaching of synthetic melanins and hair. University of Keele, 1996.

2. Takahashi, T.; Nakamura, K., A study of the photolightening mechanism of red hair with visible and ultraviolet light: Comparison with blond hair. J. Cosmet. Sci. 2005, 56 (1), 47-56.

3. Zavik, C.; Milliquent, J., Hair Structure, Function, and Physicochemical Properties In The Science of Hair Care, 2nd ed.; Bouillon, C.; Wilkison, J., Eds. Taylor & Francis Group, LLC: London, 2005; pp 29-35.

4. Hoting, E.; Zimmermann, M.; Höcker, H., Photochemical alterations in human hair. II: Analysis of melanin. J. Soc. Cosmet. Chem. 1995, 46 (4), 181-190.

5. Nogueira, A. C. S.; Dicelio, L. E.; Joekes, I., About photo-damage of human hair. Photochem. Photobiol. Sci. 2006, 5 (2), 165-169.

6. Zviak, C., The Science of Hair Care. Taylor & Francis: 2005.

7. Hoting, E.; Zimmermann, M.; Hilterhaus-Bong, S., Photochemical alterations in human hair. I: Artificial irradiation and investigations of hair proteins. J. Soc. Cosmet. Chem. 1995, 46 (2), 85-99.

8. Hoting, E.; Zimmermann, M., Photochemical alterations in human hair. Part III: investigations of internal lipids. J. Soc. Cosmet. Chem. 1996, 47 (4), 201-211.

9. Davis, S. L.; Marsh, J. M.; Kelly, C. P.; Li, L.; Tansky, C. S.; Fang, R.; Simmonds, M. S. J., Protection of hair from damage induced by ultraviolet irradiation using tea (Camellia sinensis) extracts. Journal of Cosmetic Dermatology 2022, 21 (5), 2246-2254.

10. Marsh, J. M.; Davis, S. L.; Fang, R.; Simmonds, M. S.; Groves, P.; Chechik, V., UV Oxidation: Mechanistic Insights Using a Model System. J. Cosmet. Sci. 2021, 72, 697-710.


I had to listen to what my hair curls are finally ready to take in some moisture again!!!


- renee, Stylist Liaison

- renee, Stylist Liaison

“I truly couldn't have gotten through this without her knowledge, advice and support...after suffering from Hygral Fatigue and getting tons of advice @themestizamuse.”

“@themestizamuse: for ESSENTIAL information you will NEED TO KNOW in order to see results.”

See how easy the topics are to find on her page (a few posts screenshot)? There is no topic Verna hasn't covered.

- dominique P, wavy hair enthusiast


- dominique P, wavy hair enthusiast

“I have learned a whole heap of knowledge from @themestizamuse.”

Inspiring hair tutor, grateful for what she offers the Curly Community in authenticity, passion, and knowledge.

- zoe F, Producer & Host of The Curl Squad


- zoe F, Producer & Host of The Curl Squad

“I was so excited to embrace my curls and take better care of them. As I started to dive in, I immediately became overwhelmed with the information.”

I read books and tried doing things because "that's what I'm supposed to do," but it didn't always work and I didn't understand why. I'm so grateful for Verna and her blog. Her info. actually helped me understand more of the science of why some methods helped and what products or ingredients to use and why. Anyone that compliments my hair and wants to start a curly journey, I tell them to start here. My hair is so much healthier and I'm so happy with it.

- stephanie, Curly hair enthusiast


- stephanie, Curly hair enthusiast

Our Manifesto

“One day you will wake up and there won't be any more time to do the things you've always wanted. Do it now”

- Paulo coelho

Skip to content