Function
While Acetyl tetrapeptide-5 is used in cosmetic eye formulations to decrease puffiness, eye bags, and dark circles by reducing edema and protecting proteins such as SOD from glycation51150159154, 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 Acetyl tetrapeptide-5 works as a synthetic tetrapeptide, Ac-βAla-His-Ser-His (Eyeseryl), with reported ACE-1 inhibition and anti-glycation activity, proposed to improve microcirculation and reduce capillary permeability and fluid accumulation in periorbital tissues51150159157, 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
Acetyl tetrapeptide-5 is 4 amino acids long, whereas Sermorelin is longer as it has a length of 29 amino acids. Acetyl tetrapeptide-5 is made up of a sequence of βAla, Histidine, Serine, Histidine. 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.