Function
While Matrixyl is a widely used cosmetic peptide with evidence of stimulating extracellular matrix synthesis and reducing wrinkle appearance in skin-care formulations48, Sermorelin is used as a diagnostic agent for assessing GH secretory capacity and as a research tool or off-label therapy to increase endogenous GH in GH-deficient or age-related contexts1727.
Mechanism
While Matrixyl works as a palmitoylated pentapeptide, Pal-Lys-Thr-Thr-Lys-Ser (Pal-KTTKS), that acts as a matrikine, signaling to dermal fibroblasts to increase production of collagen, elastin, fibronectin, and other ECM components4858, Sermorelin is a synthetic 29-amino-acid peptide identical to the 1–29 N-terminal fragment of human GHRH that stimulates GH synthesis and secretion by binding pituitary GHRH receptors1727120.
Length and Sequence
Matrixyl is 5 amino acids long, whereas Sermorelin is longer as it has a length of 29 amino acids. Matrixyl is made up of a sequence of Lysine, Threonine, Threonine, Lysine, Serine. Sermorelin is made up of a sequence of Tyrosine, Alanine, Aspartic acid, Alanine, Isoleucine, Phenylalanine, Threonine, Asparagine, Serine, Tyrosine, Arginine, Lysine, Valine, Leucine, Glycine, Glutamine, Leucine, Serine, Alanine, Arginine, Lysine, Leucine, Leucine, Glutamine, Aspartic acid, Isoleucine, Methionine, Serine, Arginine.