Colour-treated hair sits at one end of the Treatment Status axis: it has undergone a chemical process such as colouring, highlighting or permanent styling. This changes the outer layer of the hair (the cuticle) and its porosity. Moisture and ingredient needs therefore have a different context from natural hair.
What Does Colouring Change?
The colouring process temporarily opens the cuticle layer so colour can enter the strand. Commonly observed effects include:
- Increased porosity: The strand may tend to absorb moisture more quickly and lose it more quickly.
- A tendency to lose moisture: Colour-treated hair may feel dry sooner than natural hair.
- A tendency for colour to fade: Colour may lighten with time and external factors such as washing, heat and sunlight.
These are frequently observed tendencies, not absolute rules; not all hair or treatments are the same.
For Colour-Treated Hair, Which Ingredient Families Stand Out?
For colour-treated hair, moisture-retaining, emollient and film-forming or repairing ingredient families stand out. Some familiar examples to look for on a label include:
- For moisture and softness, ingredients such as panthenol, argan oil, jojoba oil and coconut oil.
- For a film on the strand's surface and a smoother feel, hydrolysed collagen and other repairing proteins; hydrolysed keratin and wheat protein are also common examples in this family.
These families do not promise a result on their own; they are options to consider more closely in the context of your hair.
Colour in Context: Sulphates and Heat
Strong cleansers and high heat are two common factors that can speed up colour fading. Gentler cleansing profiles and moderate heat use are therefore often preferred for colour-treated hair. We discuss how to assess cleansing chemistry in our article on sulphates. This does not claim a product protects colour; it is about understanding the formula in context.
Three Practical Observations
- Consider porosity and frequency. Frequently coloured or bleached hair may be more porous; moisture-retaining and emollient families stand out in this context.
- Consider sulphates and heat. Strong cleansers combined with frequent heat use may increase the tendency for colour to fade; a gentle cleansing profile and moderate heat may be an option.
- Keep the medical boundary clear. Scalp redness, itching or an allergic reaction after colouring (such as PPD sensitivity) requires medical assessment. A patch test before a new dye, and consulting your clinician when in doubt alongside the scalp guide, may be helpful.
This article is for information only; it does not provide a medical diagnosis, treatment or a guarantee of safety. If you have sensitivities, are pregnant or have particular circumstances, you are advised to discuss your decisions with your own doctor.