Arginine (and) Serine (and) Threonine (and) Proline

This specific blend of four amino acids — Arginine, Serine, Threonine, and Proline — is formulated to mimic the natural moisturizing factor (NMF) composition found in the stratum corneum, making it particularly effective at reinforcing the skin's own hydration mechanisms. Arginine contributes wound-healing and barrier-supporting properties, Serine and Threonine provide hygroscopic moisture-binding, while Proline is a key structural component of collagen and helps maintain skin elasticity and resilience. Formulators choose this complex for its synergistic multi-amino acid approach to hydration, skin barrier reinforcement, and compatibility with a wide range of cosmetic systems including serums, moisturizers, and hair care products.