What affects the porosity of hair?

The porosity of hair is primarily influenced by the condition of the cuticle layer, as well as any damage that may have occurred from chemical or physical processes. The cuticle layer consists of overlapping scales that protect the inner structure of the hair. When the cuticle is healthy and intact, the hair has lower porosity, meaning it can resist moisture absorption and retain its natural oils. Conversely, when the cuticle is damaged—due to factors such as chemical treatments (like coloring or perming), heat styling, or mechanical effects (like excessive brushing)—the hair becomes more porous. This increased porosity allows the hair to absorb moisture and other substances more readily, but it can also lead to dryness and frizz as the hair loses its ability to retain moisture.

While hair color, texture, length, and environmental factors can also play roles in the overall health and appearance of hair, their direct influence on porosity is significantly less compared to the condition of the cuticle and the extent of damage incurred. For example, while environmental factors can impact moisture levels and contribute to hair dryness, they do not inherently change the structural integrity of the cuticle layer itself. Therefore, focusing on the condition of the cuticle and the resulting impact from any damage provides