Peptides are a relatively new, but already quite popular component of cosmetics: they were discovered only 40 years ago, began to be used in medicine ten years later, and cosmetic production technologists noticed them only at the beginning of the 2000s. Peptides are made up of amino acids. Amino acids are the basic building blocks of all living organisms. Their compounds are called either peptides or proteins. The difference is in the length of the chain: a molecule with less than 50 amino acids is a peptide, and more is a protein. Peptides are found in small amounts in almost all living cells. Hormones and blood plasma constituents are also them.