Does Dyeing Curly Hair Damage It?

We’ve heard that dyeing curly hair can lead to damage and a loss of curl pattern, but is it true?

does colouring hair affect curl pattern?

The truth is that hair dyeing or bleaching will affect all types of hair across all textures, porosity levels and densities to some degree.

Dyeing hair involves depositing or removing colour and any permanent change will involve lifting the cuticle layer. This in turn increases the porosity.

Low porosity hair is considered healthy because the cuticle lies flat, protecting the inner structure of the hair.

High porosity hair has a raised cuticle layer which can expose the inner structure, making the hair vulnerable to damage.

colouring curly hair affects the cuticle and can damage it

Before we go any further, let’s have a quick look at the different methods of colouring that you will encounter at a salon.

does colouring curly hair at a salon damage it?

Types of Hair Dye

Hair dyes are classified by how permanent they are. This in turn correlates with how far into the hair shaft the colour penetrates.

Non-permanent (demi or semi-permanent colours)

These don’t penetrate all the way to the cortex (the layer beneath the cuticle) and will stay at the cuticle level. This is why they can be removed gradually by washing. 

Permanent dyes

These will reach the cortex of the hair. They achieve this by removing the protective external lipid layer (derived from sebum) from the strands and lifting the cuticle layer so they can deposit the colour more deeply. 

Gaps created in the cuticle layer by the raised cuticle scales allow more moisture to pass in and out of the hair. The hair strands are more likely to swell when wet which can cause damage to the hair’s structure but will also lose moisture faster which can lead to dry hair.

When curly hair is damaged it can lead to a loss of curl pattern. This is only the case for the damaged strands, new hair will continue to grow with the curl pattern intact.

Does dyeing curly hair damage it? Non-permanent dyes will only reach the hair’s cuticle layer, meaning that they are gentler on the hair and less likely to cause damage.

dyeing curly hair

Curly hair is likely to be more vulnerable to damage from colour because it tends to be drier than straight hair. This increases the chances of the hair strands being damaged and the porosity level being increased.

In turn, the initial porosity level of hair will affect its ability to take on colour.  Low porosity hair is more difficult to dye because the cuticle layer is more ‘closed’ than on high porosity hair. On the other hand, high porosity hair tends to accept colour easily because the cuticle layer is already open.

The extent to which dyeing affects your curl pattern is determined by your porosity level and the method of colouring that you choose. 

curly hair podcast

What About Bleaching?

To remove the hair’s colour the cuticle again needs to be raised. This allows the oxidative agents in the bleach to reach the natural pigments (known as melanin) within the inner cortex. The melanin is dissolved to achieve a lighter effect. 

using bleach to colour hair

Bleaching is the most damaging way to colour hair so extra care should be given to bleached hair.

Holes or ‘pores’ in the cuticle can begin to form very quickly once the bleach is applied. Repeated bleaching can lead to a complete loss of the cuticle layer, exposing the cortex.

Wet bleached hair needs to be handled with additional care as it is very fragile. Gentle washing and drying are crucial, the less friction and external mechanical forces (tools, towels, heat) that you apply at this point, the better.

Bleaching your hair can affect your curl pattern if the process isn’t done with care and the level of developer used is too strong.

My best-selling product…

one week curl plan book

Ways to Lessen the Impact of Colour on Curly Hair

Does dyeing curly hair damage it? Most kinds of colouring processes will have a negative effect on our hair, so what can we do to minimise damage?

  • Speak to your stylist. Always tell your stylist your full colour history so they can make the best decision for your hair. 
  • Use Olaplex. This is a bond-rebuilding treatment. You can ask for it at the salon but you can also buy it as a treatment to use at home. It rebuilds bonds broken during the colouring process. They also produce shampoos, conditioners and styling products, too.
  • Lower PH levels after colouring. PH levels are higher after colouring processes. For the first wash after my colour, I do a final rinse with apple cider vinegar which has an acidic PH and helps to lower the cuticle. I put about a teaspoon into a large glass of filtered water and pour this over my hair as the last step in my wash routine. Don’t rinse this out – the smell will disappear!

I use Bragg’s Apple Cider Vinegar to do this

This is my favourite deep conditioning treatment by Noughty

These steps will help to minimise damage from hair dyeing and bleaching and allow us to continue being creative with our hair colour whilst retaining our curl and wave patterns.

Speak soon,

Lauren xx

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