Amino Acids

Amino acids are the building blocks of proteins like collagen, keratin, and elastin. They are also major components of the skin natural moisturizing factors (NMF), a complex of water-soluble compounds that keep the stratum corneum hydrated. Common amino acids in skincare include glycine, alanine, serine, arginine, and proline.

When applied topically, amino acids help replenish the NMF, improving hydration and barrier function. They also support protein synthesis, helping skin repair and maintain its structure. Amino acids are particularly beneficial for damaged or compromised skin barriers, as they provide the raw materials skin needs to rebuild.

Japanese skincare often features amino acid complexes in gentle cleansers and hydrating toners. Brands like Minon and Cow Brand focus on amino acid formulations for sensitive and dry skin. Amino acid surfactants are also popular in Japanese cleansers for their mildness.