Fundamental constituents of all proteins found in the body, such as: alanine, arginine, asparagine, aspartic acid, cysteine, cystine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. Some of these amino acids can be synthesized by the body; others (known as essential amino acids) must be obtained from protein in the diet.
In skincare products, amino acids act as water-binding agents, and some have antioxidant properties and wound-healing abilities as well.  Amino acids can be combined with other ingredients that have cell communicating ability to work in unison to fight wrinkles and other signs of aging. 
- Angele M, Nitsch S, Hatz R, Angele P, Hernandez-Richter T, Wichmann M, Chaudry I, Schildberg F. L-arginine: a unique amino acid for improving depressed wound immune function following hemorrhage. Eur Surg Res. 2002 ;34(1-2):53-60.
- Auriol, D, Redziniak Libragen G, Schweikert K, Lefevre F. Collagens I and III, and Elastin Activation for Anti-aging. Cosm & Toil. 2014; 129(2) 70.
natural moisturizing factor (NMF)