How do emollients (moisturisers) work?
Despite their apparent simplicity, the ways which emollients work are quite sophisticated. One way in which emollients (moisturisers) help to increase skin hydration is by forming films of lipid on the surface of the skin. These lipid films reduce the level of trans-epidermal water loss (TEWL) from the skin, allowing moisture levels within the outer layer of the skin (the stratum corneum) to increase and the skin to become pliable. Other ingredients known as humectants (e.g. glycerin) may also be added to emollient (moisturiser) products to help retain moisture. Lubricants may also be added to improve skin feel. However, it is not only occlusivity which determines the efficacy of an emollient. In recent years, a great deal of research has been carried out into what is referred to as the ‘barrier function’ of skin. One useful analogy is that the stratum corneum is very much like a miniature brick wall where the skin cells (the bricks) are held within a natural, lipid mortar (called stra
