Diminishing skin reserves of hyaluronic acid: As skin ages, mature skin produces less hyaluronic acid, a natural molecule essential for maintaining skin hydration. Over time, skin dries out because it can no longer retain the water that moisturizes it from within.
Seasonal changes: Skin dehydration often occurs in winter or when the season changes. As the hydrolipidic film secreted by the sebaceous glands is much in demand, its capacity to protect the skin from external aggressions (temperature change, cold...) diminishes.
Heat: whether from electric heating or the sun, heat tends to dry out the epidermis, leading to evaporation of water from the skin. Air conditioning also has a drying effect on the face.
Other factors can also cause skin dehydration, such as stress, poor lifestyle habits (alcohol consumption, smoking...), an unsuitable skincare routine...