What are the functions of polypeptides in skin care?

The biological activity of polypeptides depends on their amino acid composition and sequence. Almost all physiological processes in human body are regulated by polypeptides or proteins composed of specific amino acid sequences. Therefore, bioactive peptides have become a new direction and idea for cosmetics research and application, and their functions are more and more subdivided, such as anti-aging, repair, anti-oxidation, anti-edema, promoting hair regeneration, inhibiting melanin production, breast enlargement, weight loss, etc.
Skin is the natural barrier for human body to resist the invasion of external environment. It has a protective effect on external stimulation, which benefits from the protective effect of the dense cuticle of the skin. However, the nutritional components of cosmetics are also blocked on the skin surface. Nutrients need to penetrate the cuticle cell membrane to enter the dermis. Only a small amount of macromolecules and fat-soluble substances can be absorbed through pore and sweat pore. So most of the cosmetics we usually use only stay on the skin surface, while the biologically active cosmetic peptides can easily enter the dermis through the cuticle space and play a role.
Peptides were first used directly in products by some European and American cosmetics. Their mechanism is similar to that of proteins. They can promote the proliferation of collagen, elastic fibers and hyaluronic acid, increase the moisture content of skin, increase the thickness of skin and reduce fine lines. Because of the different kinds of amino acids, they can play different roles to meet the needs of different skin functions.