A composition comprising a mixture of isolated amino acids, the mixture of isolated amino acids comprising: a) 15 to 35 wt% glycine, based on the total solid weight of a) to g), b) 5 to 25 wt% proline, based on the total solid weight of a) to g), c) 5 to 25 wt% glutamine, based on the total solid weight of a) to g), d) 5 to 25 wt% hydroxyproline, based on the total solid weight of a) to g), e) 1 to 20 wt% arginine, based on the total solid weight of a) to g), f) 1 to 20 wt% alanine, based on the total solid weight of a) to g) and g) 1 to 15 wt% D-aspartic acid, based on the total solid weight of a) tog)； wherein the amount of a), b), c), d), e), f) and g) gives a total of 100 wt% based on the total solid weight of a) to g). The composition may be included in a capsule or tablet and may be used to improve the appearance of the skin.
