sh-Tetrapeptide-38 Trifluoroacetate is the trifluoroacetate salt of a single chain human peptide, produced synthetically to be identical to a portion of the protein, Stem Cell Factor which contains a maximum of 273 amino acids. sh-Tetrapeptide-38 Trifluoroacetate contains 4 amino acids consisting of aspartic acid, leucine, and lysine.