Peptides are segments of proteins and occur in a wide variety in the body exerting many important physiological functions. When applied topically to skin peptides have been shown to have various benefits including (e.g. anti-aging activity). Today, dozens of peptides are used in skin care products and there are many more currently in development. Even though peptides consist of natural components (amino acids) most peptides that are used in personal care products are synthetic. Peptides are extremely hydrophilic (water-soluble) and therefore easy to use in cosmetic formulas. However, peptides are relatively heat sensitive. In order to be functional, peptides must be stable in their base formula, they must be paired with a specific carrier that enhances their absorption into the skin, and they must be able to reach their target cell groups without breaking down. Because peptides are small, they can penetrate the skin's protective barriers to get to the deeper layers of the dermis.