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, Thymosin Alpha-1 is clinically used in some countries as an immunomodulator for chronic hepatitis B/C and as an adjuvant in cancer therapy, enhancing cell-mediated immunity41487.
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, Thymosin Alpha-1 is a 28-amino-acid thymic peptide fragment of prothymosin alpha that activates dendritic cells and T cells primarily via TLR9/MyD88/NF-κB signaling, enhancing Th1 responses and NK-cell cytotoxicity414.
Length and Sequence
Acetyl tetrapeptide-5 is 4 amino acids long, whereas Thymosin Alpha-1 is longer as it has a length of 28 amino acids. Acetyl tetrapeptide-5 is made up of a sequence of βAla, Histidine, Serine, Histidine. Thymosin Alpha-1 is made up of a sequence of Serine, Aspartic acid, Alanine, Alanine, Valine, Aspartic acid, Threonine, Serine, Serine, Glutamic acid, Isoleucine, Threonine, Threonine, Lysine, Aspartic acid, Leucine, Lysine, Glutamic acid, Lysine, Lysine, Glutamic acid, Valine, Valine, Glutamic acid, Glutamic acid, Alanine, Glutamic acid, Asparagine.