What is the function of the cuticle layer of hair?

The cuticle layer of hair serves a vital protective role for the inner structures of the hair strand. It is composed of overlapping, scale-like cells that form a barrier, safeguarding the more delicate cortex and medulla layers beneath it. This protective barrier helps prevent damage from environmental factors, chemical treatments, and physical stress. Additionally, the cuticle layer aids in maintaining moisture within the hair shaft, which is crucial for hair health, elasticity, and shine. Without the cuticle functioning effectively, hair could become brittle, dry, and more susceptible to breakage and other forms of damage.