sh-Pentapeptide-17 SP is a single chain human peptide produced synthetically to be identical to a portion of the protein, Pappalysin-1, and consists of asparagine, aspartic acid, lysine and methionine. The parent protein contains a maximum of 1627 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 standard amino acids.