A peptide is a chain of protein molecules that serves as a messenger within your body. For your skin, this means that peptides transmit information back and forth between the dermis (the deeper tissue level of your skin) and the epidermis (the surface of your skin). Specifically, they tell the inner levels of your skin when the surface needs repairing.
As we age, the peptide messenger bonds deteriorate, and our skin loses the ability to repair itself as effectively. Skincare companies have begun to tap into the antiaging potential of peptides, hoping that using them in topical creams will mimic the body's natural production of them and stimulate the reformulation of collagen and general healing and brightening of the skin's surface.
As with any cutting-edge skin care, peptide-based products can be pretty pricey. Let me know if you would be interested in a product post about peptides!