Sebum membrane is a protective layer formed by the fusion of sebum, lipid and sweat secreted by the skin, and it is the first factor for our skin to lock water and have healthy and fair skin. Once the skin loses the protection of sebum membrane, the delicate skin is directly exposed to the air, which will soon become dry, itchy and even molting, causing sensitive skin problems. It can also replenish the lost lipid for the skin and rebuild a complete sebum membrane.