What is the primary function of the cuticle in hair?

The primary function of the cuticle in hair is to protect the inner layers of the hair strands. The cuticle is the outermost layer, consisting of overlapping, scale-like cells that tightly adhere to one another. This structure serves as a barrier, shielding the more delicate and vulnerable layers beneath, including the cortex and medulla. By effectively safeguarding against environmental damage, chemical exposure, and mechanical wear, the cuticle plays a crucial role in maintaining the overall health and integrity of the hair.

The cuticle does not add color to the hair; that role is largely attributed to the melanin present in the cortex. While a healthy cuticle can enhance shine, it is not its primary function. Providing moisture is also not a role of the cuticle; instead, the hair's moisture retention is influenced by factors like the hair structure and the amount of moisture in the surrounding environment. Each of these aspects highlights the specific protective nature of the cuticle as essential for hair health and resilience.