Skin is made up of three main layers: an epidermis, with the important top layer, stratum corneum (“horny layer”), and a dermis. Every layer of the skin works in harmony with the others. The skin is constantly renewing itself, and anything that throws its functions off balance affects all skin layers at the same time. Keeping skin moist For most people, proper skin care starts with adequate hydration. But as shocking as it sounds, healthy skin doesn’t really need any additional moisture.
Our skin is perfectly able to keep itself hydrated. Its surface is kept soft and moist by sebum and a natural moisturizing factor (NMF). Sebum, a clear waxy substance made of lipids, acts as a natural emollient and barrier. It helps protect and waterproof hair and skin and keep them from becoming dry and cracked. It can also inhibit the growth of microorganisms on the skin. Sebum, which in Latin means “fat” or “tallow, ” is made of wax esters, triglycerides, fatty acids, and squalene.
The amount of sebum we produce varies from season to season and can be predetermined genetically, but in fact, the amount of sebum needed to keep skin moist and healthy is very small. People who are “blessed” with oily skin think their skin is dripping oil, but they produce only 2 grams of sebum a year! For some reason, sebum became public enemy number one in the fight for clearer skin.