Why colour-treated hair is more vulnerable

Every time you colour your hair, the chemical process opens the cuticle — the outer protective layer of the hair shaft. The dye penetrates inside, but the hair’s structure is no longer as dense as it was before colouring.

Colour-treated hair has increased porosity: the cuticle scales lie less flat, leaving micro-gaps between them. Through these gaps, hair loses both moisture and pigment more quickly — especially under heat.

Important
The more often you colour your hair, the more porous its structure becomes. After 3–4 colour treatments without restorative care, the cuticle can be so open that the protective effect of heat products is reduced. A regular collagen mask helps to partially restore the density of the hair shaft.