Peptides are strings of amino acids, held together by nitrogen and carbon bonds. Under the microscope, they have a similar appearance to a string of pearls. Peptides have been around since the birth of tissue, and scientists recognize them as the building blocks of life. In the skin, peptides occur naturally to keep the skin firm. In skin care products, lab-created peptides work from the inside out to address a host of facial issues, especially wrinkles.
The pivotal benefit of peptides in skin care is their ability to penetrate the skin. This is a result of their size at a molecular level. Peptides consist of up to 100 amino acids strung together, so they are actually mini-proteins: chains of 100-200 amino acids are called polypeptides, and chains of more than 200 are simply called proteins.
Long-chain proteins, such as collagen, can only be applied to the surface of the skin, because their molecular size makes it impossible for them to go deeper. The best they can do is to act as a temporary moisture barrier to promote hydration and softness. But when these long-chain proteins are broken into shorter chains (peptides), skin penetration becomes possible.
Peptides are non-invasive ingredients that have been proven to produce results, so they are great options for incorporating into a skin care regimen. Know, however, that peptides are not quick and magic potions. Their one drawback is that they take time because they build from within the skin, not from peeling the outer surface. The positives of this approach: stronger skin, less or no irritation, and no free-radical stimulation.