Decolorization: Process of removing natural or artificial pigment from hair

ByDr. Celestine (Certified Trichologist)

What is Decolorization?

Decolorization is a chemical process that removes natural or artificial pigment from the hair shaft. It works by breaking down melanin, the pigment that gives hair its color, to lighten it to a desired blonde or prepare it for a new color.

Most people think it just lightens hair, but it actually changes the hair’s fundamental structure. I see this process as the most aggressive yet transformative service in hair coloring.

Why Decolorization Explodes the Hair Cuticle

Decolorizing agents, like bleach, force the hair’s outer cuticle layer wide open. This allows the active chemicals to penetrate the cortex, the hair’s inner core where pigment lives.

Think of your hair cuticle like a pinecone. When it’s dry, the scales are tightly closed. Decolorization is like submerging that pinecone in water, causing every single scale to swell and burst open to allow the lightening process inside.

I always warn my clients that this forced opening is permanent damage. Once those cuticle scales are blasted apart, they can never fully lie flat again, which is why decolorized hair often feels rough.

The Developer’s Hidden Role in Decolorization

The developer, or peroxide, is the engine of the decolorization process. Its volume (10, 20, 30, 40) determines the speed and power of the lift. Higher volume developers create more lift but also cause more damage.

Think of developer volume like the heat on a stove. A low volume is a gentle simmer, while a high volume is a rolling boil. Both will cook the food, but one is much harsher and risks burning it.

In my clinic, I never use 40 volume on the scalp. The risk of severe chemical burns and hair fracture is simply too high, no matter how resistant the hair seems.

When Decolorization Attacks Your Hair Bonds

Beyond pigment, the process also breaks down the hair’s disulfide bonds, which are its primary source of strength. This is what leads to the mushy, over-processed feel if the formula is left on too long.

I compare these bonds to the steel rebar inside a concrete building. Decolorization doesn’t just remove the color (the paint); it also corrodes that critical internal steel framework, weakening the entire structure.

About 80% of the breakage I see is from at-home decolorization where these bonds were compromised beyond repair. The hair snaps off with minimal tension.

The Surprising Truth About Underlying Pigment

A fact that surprises most people: decolorization doesn’t turn dark hair blonde. It simply strips away color in stages to reveal the underlying warm pigment that was always there.

Dark brown hair doesn’t become blonde; it becomes orange, then yellow, then pale yellow. That’s why toner is absolutely necessary to neutralize those warm tones and achieve a clean, cool blonde.

I have to explain this underlying pigment chart to clients every single day. Managing their expectations about the stages of lightening is the key to their satisfaction.

Will Decolorization Work For You?

Yes

  • If your hair is in good condition with good elasticity.
  • When you commit to a rigorous aftercare routine with bond builders and deep conditioners.
  • If you have a professional assessment confirming your hair can withstand the process.

No

  • If your hair is already damaged from previous coloring or heat styling.
  • When you have existing scalp conditions like psoriasis or open abrasions.
  • If you are not willing to accept the required upkeep and root maintenance.

From My Experience

Through my practice, I’ve developed a pre-decolorization test. I assess the hair’s elasticity by stretching a single wet strand. If it snaps immediately without stretching, I absolutely refuse service.

This simple test has saved countless clients from catastrophic hair loss. The integrity of the hair’s protein structure is everything, and once it’s gone, it cannot be truly replaced.

The biggest mistake I see is using the same formula from roots to ends. The heat from the scalp processes the product faster, so I always mix a separate, gentler formula for the mid-lengths and ends to prevent severe damage.

Healthy decolorization isn’t about achieving the lightest blonde in one session. It’s a strategic, often multi-appointment process that prioritizes the long-term health of the hair above all else.

Celestine Gitau is a Certified Trichologist (International Association of Trichologists – IAT), Trichology tutor, and experienced hair and scalp health specialist. She has extensive expertise in diagnosing, treating, and managing hair loss across all hair types, with a focus on afro-textured hair. Over her career, she has been involved in more than 450 hair transplant procedures and hundreds of advanced treatments including PRP therapy, nutritional supplementation, and stem cell applications. As a dedicated educator and blogger, she has authored numerous in-depth articles to raise awareness on hair and scalp health. Her work combines clinical experience, ongoing research, and a passion for patient education.
Note: The information shared is for educational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider for personalized guidance.