What is a peptide? Peptides are signaling molecules. 7000 peptides are naturally occurring. Molecule formed by combining two or more amino acids (the body has 20 amino acids). Typically less than 50 amino acids considered a peptide and more than 100 considered a protein in between called polypeptide. Peptides are part of receptors. These small signaling molecules do many different things in our body. Insulin, for example, is a peptide that is used to help the body utilize glucose (aka sugar). At nutrIV Therapies, we utilize many different peptide therapies to help patients achieve better results from conditions they may be suffering from.