Chemically speaking, hydration denotes the arrangement of water molecules to create a protective hydration shell through the formation of hydrogen bonds. This envelope offers protection from factors such as environmental stressors and noxious agents, among others, that could damage the skin.
Moisture can leave the skin by evaporating off the skin’s surface through perspiration, but this process is limited. The skin possesses a multitude of regulatory mechanisms to keep the upper layer, known as the stratum corneum, adequately supplied with moisture.