Medically reviewed by Cynthia Cobb, DNP, APRN, WHNP-BC, FAANP — written by Rachel Nall, MSN, CRNA ~ above September 7, 2021

We’ve every heard hair dye horror stories the breakage, dryness, and also all-around indications of damage.

But if hair dye is so negative for you, why can it make your hair look therefore good? this is what you should know around the connections in between hair dye and also hair health.

Proteins do up around 95 percent the a dry hair strand. These proteins act like a roof’s shingles, protecting the strand under from:

moistureheatUV rays indigenous the sun

Applying permanent or demipermanent hair dye or bleach creates a chemical reaction that reasons these protective protein to lift, permitting chemicals to pass through the hair strand. There, the hair dye transforms the chemical makeup of the hair. The an outcome is a shade change.

Permanent or demipermanent hair dye is a different process from temporary or semipermanent hair dyes. Short-term dyes leave color on her hair however don’t usually permeate deeper class (though they can still damage your hair). This is true for alternatives to traditional hair dye like Kool-Aid, carrot juice, and even coffee.

Altering the hair’s protein structure through permanent and demipermanent dyeing can reason side effects that include:

loss of hair strength less capability for your hair to handle warmth stylingreduced hair thickness enhanced roughness the hair follicle

Keeping this in mind, the hair dyeing procedure changes the hair by nature. The short- and long-term results of this depend on her hair structure.

If her hair is already thin or brittle, dyeing have the right to make it even weaker. Special hair can additionally experience side impacts from dyeing due to the fact that the dye might take much longer to “lift” the hair proteins, and also it may require much longer applications.

What chemicals need to I watch out for?

The adhering to are part chemicals generally used in the hair dyeing process.


Bleaching hair transforms the colours that give hair the color. A 2020 study discovered that bleaching can affect:

hair strengthmoisturehair’s capacity to withstand heat

The level to which bleach loss the hair relies on the pH (or acidity) of her hair and can likewise be affected by the pH of the environment around you.

You are watching: Is dying your hair a chemical change

Bleaching is generally done by applying hair dye that has hydrogen peroxide. Hydrogen peroxide is one oxidizing agent. This means it activates the hair color, however the oxidizing procedure does cause damage.


Henna is a organic semipermanent hair dye. However, “natural” no mean less damage.

A 2019 study uncovered that henna water can damages your hair, leading to coarser, more brittle hair. Once the henna dye was left on much longer than one hour, the damages was comparable to the of hair bleaching.

Henna can also cause call dermatitis and also skin irritation, specifically if you’re allergic to any type of of the compounds or ingredients in henna ink.


P-phenylenediamine (PPD) is a chemical compound generally found in hair water that need an oxidizer favor hydrogen peroxide.

Some people report better incidences of allergic reactions because of PPD hair dyes.

When it involves lightening her hair, the an ext you have to bleach it, the higher the damage.

A 2019 research that offered microscope modern technology to look at at degrees of bleaching discovered that hair fibers were many damaged by lengthy bleaching, specifically the kind required to change really dark hair to lighter hair. This is why many hair colour specialists execute not recommend significantly lightening the hair in ~ one time.

Going from lighter to darker isn’t necessarily less damaging because you room still changing the hair’s structure. It’s essential to take treatment of hair that’s been dyed darker as well.

History of prior hair damage from heat styling or harsh dyeing practices have the right to increase the likelihood of more hair damage.

Here room some ways you can assist protect your hair:

Limit warmth styling. Warm styling can further weaken hair. Border your use of warmth styling tools, such as:hair dryerscurling ironsflat irons Apply thermal heat protectant sprays or lotions. apply these to the hair before heat styling. Allow time to pass in between hair dyeing appointments. Less regular hair dyeing appointments can assist minimize damage. Use moisturizing shampoos and also conditioners. this products aid the hair host moisture ~ dyeing. Extremely fragranced shampoos through high quantities of detergents (they usually have actually a the majority of lather) often tend to be much more damaging.

See more: What Is The Conflict Of The Necklace ? Conflict In The Necklace By Guy De Maupassant

Choose color-specific shampoos, conditioners, and other hair care products. These room meant to assist protect color-treated hair. Consider dyeing her hair closer come its natural shade. This may assist limit damage whenever possible.