Glycine

A non-essential amino acid (the building blocks of skin proteins, like collagen or elastin), that the body can produce itself, but its production decreases with age. When you put it all over your face, it works as a moisturizerand maybe more. 

According to great skincare blog Futurederm, glycine might help with wound healing and tissue repair and when used together with other amino acids, leucine and proline it might improve wrinkles. 

BTW, it's also a building block of a bunch of important and famous peptides, including copper-tripeptide-1, palmitoyl tripeptide-1 or palmitoyl hexapeptide-12.