Dry skin begins with a deterioration of the skin barrier. As it becomes less impermeable, it struggles to regulate water loss from the deeper layers of the skin into the ambient air. The skin thus gradually loses its NMFs, or natural moisturising factors, which ensure the hygroscopicity of the stratum corneum. This disruption compromises the skin’s biological activity, particularly in relation to aquaporins, proteins involved in the transport of water between epidermal cells. The result: the skin slowly but surely dries out, flakes and becomes rough. Apart from factors associated with certain medical conditions and medications, there are three main causes of this deterioration in the skin barrier’s protective efficacy.
An unsuitable skincare routine: repeated rubbing, cleansers that are too harsh or the use of water that is too hot during your skincare routine can dissolve the lipids that make up the outermost layer of the epidermis. Scientists agree that the use of so-called ‘stripping’ cleansers tends to increase insensible water loss (1)
Skin ageing: as we age, the skin produces less sebum and loses much of its ability to defend itself effectively against factors that cause dehydration. This is why mature skin is often dry, and vice versa, as skin that is not properly moisturised is also skin that shows signs of ageing more quickly
An unbalanced diet : what you eat (and what you do not eat in sufficient quantities) also has an impact on the skin’s hydration levels. Several studies have shown that deficiencies in linoleic acid (a polyunsaturated fatty acid), calcium and vitamin C can all disrupt the homeostasis of the skin barrier (2).














