The cause of oily or unclear skin is excessive sebaceous gland activity in the dermis. The function of these glands is to produce an oily substance which, when joined with epidermal lipids (produced by keratinocytes, e.g. the most common type of skin cells), forms a hydrolipid film on the skin. In normal conditions, this protective emulsion of water and sebum performs a protective and hydrating function, maintaining the skin’s moisture, elasticity, and nourishment. If sebum secretion is excessive, the skin appears oily and shiny, with dilated pores and a thick horny layer. It also prevents skin from breathing and increases microorganism and bacteria activity. The skin is hyperkeratotic (its horny layer is excessively thick), dull, devitalised, with whiteheads and blackheads. It is especially prone to infection and can develop acne.
Skincare for this specific type of skin contains exfoliating active ingredients, such as glycolic acid, which helps eliminate impurities and dead epidermal cells, as well as reducing the thick horny skin layer. Nevertheless, oily skin needs hydration. This is provided by a natural active ingredient, hyaluronic acid.