Some researchers believe that collagen keeps skin young is not scientific, they believe that skin can be kept young thanks to epidermal stem cells. Mammalian epidermal cells are continuously renewed, and cells are derived from epidermal stem cells. These stem cells attach to the basement membrane through a specialized differentiated multi-protein structure called hemidesmosomes. Epidermal stem cells will continue to replicate and differentiate to generate new cells to replace damaged old cells. This renewal is conducive to maintaining the youth of the skin. 
Collagen strips are essential for promoting the renewal of epidermal stem cells
 the renewal of epidermal stem cells is the reason for keeping the skin young.