The hair fibre that you see is composed of a protein called keratin, compacted and cemented together in layers. Keratin is a remarkably strong protein, very resistant to wear and tear and also makes up feathers, claws, nails and hoofs.

Each scalp hair consists of two or three layers, depending on whether an intermittent central transparent core is present. Around this core is the cortex of the hair shaft, which is the thickest layer and contains the pigment - giving your hair its colour. The outer layer is the cuticle which is protective and, when smooth and intact, is reflective - giving your hair its shine.