Function
While Semax is used clinically in Russia for ischemic stroke and cognitive disorders; in models it improves learning, protects dopaminergic neurons, and modulates stress responses without significant endocrine ACTH-like effects166174, 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 Semax works as a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP), that is an analog of ACTH(4–10) with a Pro-Gly-Pro extension and exerts neurotrophic and neuroprotective actions partly via upregulation of BDNF and modulation of dopaminergic and glutamatergic systems40162165174, 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
Semax is 7 amino acids long, whereas Sermorelin is longer as it has a length of 29 amino acids. Semax is made up of a sequence of Methionine, Glutamic acid, Histidine, Phenylalanine, Proline, Glycine, Proline. 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.