Amino Acids — Amino acids are naturally present in skin, as part of what’s called our natural moisturizing factors (NMFs). Within skin’s uppermost layers, amino acids work to move moisture throughout skin, allowing our skin to thrive and stay hydrated. Because of this, the primary benefit is that the amino acids help maintain skin’s smoothness and hydration, something they also do when applied via skin care products. There are at least 20 amino acids that are important to our health, 11 of which your body makes on its own (alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine). The other 9 must be obtained from foods or supplements (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine). Taurine is called a ‘conditional’ amino acid. Your body can produce some amount of taurine, and you can get some of it naturally through foods.
Some amino acids work as antioxidants; however, most of them are believed to play an even greater role by helping skin create more of its own antioxidants, such as glutathione (an antioxidant produced in cells, comprised largely of glutamine, glycine, and cysteine). Topically applied amino acids help strengthen skin’s natural defense system, making it less likely to show signs of aging from environmental damage. Research has shown that synthetic amino acids often have greater hydrating ability than animal- or plant-derived amino acids.