Sericin is a natural macromolecular protein wrapped on the surface of silk fibroin. It is mainly secreted by the silk glands of silkworms and is one of the main proteins that make up the silkworm cocoon.

"Sericin" is a high molecular natural protein with a molecular weight of more than 300,000. The research results show that silk has skin affinity, and the sericin that protects the silk thread is composed of natural moisturizing factor (NMF) in the stratum corneum of human skin. The ingredients are similar.