What is the difference between protein, amino acid, and peptide? Amino acids are dehydrated and condensed to form polypeptides, which will fold to form proteins. Collagen, as a functional protein, can make the skin firm and elastic, but the protein is too large and cannot be easily absorbed by the skin. Somehow there are only few types of amino acids and limited efficacy. This makes peptide come to our sight. Through permutation and combination of 20 peptides, thousands of peptides can be formed. Different peptides have different effects. For example, glutathione can help for whitening the skin, and acetyl hexapeptide-8 can reduce expression lines. Not only that, but polypeptide also has anti-inflammatory, soothing and repairing effects. Do you know how to chose now?