sh-Pentapeptide-41 SP is a single chain human peptide produced synthetically to be identical to a portion of the protein, Immunoglobulin heavy chain junction region, and consists of arginine, glutamic acid, methionine and serine. The parent protein contains a maximum of 15 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 standard amino acids.