The stratum corneum is the outermost layer of the skin. Normally, every 28 days, the horny layer of the upper layer will automatically renew and fall off, and at the same time, the new keratinocytes of the lower layer will be pushed up to keep the skin soft and smooth. However, due to the gradual aging of physiological age, the interaction of external pressure and environmental factors, the metabolic function of the skin itself gradually slows down, resulting in lingering old keratin and new keratin can not be transferred, because the thick horny makes the appearance show The result is rough skin and disordered skin lines, which together make the skin look dull, dull, and lifeless, and indirectly affect the penetration and absorption of subsequent skin care products, so people should regularly exfoliate to achieve better skin care. Effect.