Proline Excellent Humectant Hydratation Anti-âge Proline at a glance Amino acid used in the body’s synthesis of proteins Considered a conditionally essential amino acid Helps skin retain moisture Supports structures that keep skin looking and feeling younger Proline description Proline is an amino acid that is used in the body’s synthesis of proteins. While the body can produce proline, its synthesis can be limited by certain physiological circumstances, which has led some scientists to refer to proline as a conditionally essential amino acid. In those circumstances, it must be consumed as part of a person’s diet for them to obtain the proper amount. Like all amino acids, proline helps skin retain moisture, adding to a supple look and feel. It also helps support structures that prevent the appearance of fine lines and wrinkles. As an amino acid, it is considered safe as used in cosmetics; in fact, proline is part of many peptides used in skin care. Forms of this amino acid, such as cocoyl proline, are typically used in concentrations between 0.1–5%. Related ingredients: Cocoyl Proline Dipalmitoyl Hydroxyproline Palmitoyl Proline Amino Acids