AMINO ACIDS

Amino acids such as alanine, arginine, isoleucine, valine, proline, threonine, glycine, serine, histidine, phenylalanine, aspartic acid and the derivatives sodium PCA and PCA contribute to maintaining the water balance in the uppermost layer of the skin. (1) As natural moisturizing factors (NMF) of the skin, they also support the maintenance of the skin's protective barrier. (2) The amino acids and their derivatives absorb moisture from the environment and store it in the lipid-protected corneocytes of the skin. In combination with lipids that slow down water diffusion, amino acids help the corneocytes to maintain their normal flattened, elongated shape in which they can selectively bind and retain water. (3)

(1) Oshimura, E. (2017). Cosmetic Science and Technology || Amino Acids, Peptides, and Proteins. , (), 285-303. doi:10.1016/B978-0-12-802005-0.00019-7.

(2) Ohnari, H., Sekiya, M., Naru, E., Ogura, T., Sakata, O., & Obata, Y. (2021). Amino Acids and Their N-Acetylated Derivatives Maintain the Skin's Barrier Function. Chemical & pharmaceutical bulletin, 69(7), 652-660. https://doi.org/10.1248/cpb.c21-00152.

(3) Lodén, Marie; Maibach, Howard I. (2012). Treatment of Dry Skin Syndrome || Impact of Stratum Corneum Damage on Natural Moisturizing Factor (NMF) in the Skin. , 10.1007/978-3-642-27606-4(Chapter 29), 441-451. doi:10.1007/978-3-642-27606-4_29