K18 is a brand of haircare products that focuses on restoring and repairing damaged hair. The brand's name comes from the K18 peptide, a biomimetic peptide that was discovered by scientists studying the structure of hair. This peptide is said to penetrate the hair shaft and repair damaged keratin strands from the inside out. K18 haircare products are designed to work on all hair types, from fine to coarse, and can be used on colored or chemically treated hair. K8 haircare products are designed to be simple, effective, and science-backed, with a focus on repairing and strengthening damaged hair.