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 glycation
Alanine
Ala / A · hydrophobic residue · neutral charge
AOD-9604
is studied as an anti-obesity peptide that can reduce weight gain and increase fat oxidation in obese animal models with generally neutral effects on IGF-1 and glucose metabolism in early human trials
Arginine
Arg / R · basic residue · positive charge
Argireline
is a topical cosmetic peptide reported to decrease dynamic wrinkles by partially mimicking the mechanism of botulinum toxin in a non-invasive manner
Asparagine
Asn / N · polar residue · neutral charge
Aspartic acid
Asp / D · acidic residue · negative charge
BPC-157
is investigated for accelerating healing of gastrointestinal mucosa, tendons, ligaments, bone, and nervous tissue in preclinical models, with anti-inflammatory and pro-angiogenic effects
Comparison
While Melanotan I is approved in some regions for prevention of phototoxicity in erythropoietic protoporphyria and is studied as a skin-darkening, photoprotective peptide3444, Thymosin Beta-4 promotes wound healing, angiogenesis, and tissue regeneration in preclinical models via effects on cytoskeleton dynamics, cell migration, and anti-apoptotic pathways25579.
While Melanotan I works as a linear 13-amino-acid analog of α-MSH (afamelanotide) that selectively activates MC1R on melanocytes, increasing eumelanin synthesis and providing photoprotection3444, Thymosin Beta-4 is an endogenous 43-amino-acid actin-sequestering peptide that maintains a pool of G-actin monomers and regulates actin polymerization, thereby influencing cell migration, proliferation, and differentiation25579.
Melanotan I
POMC
Thymosin Beta-4
TMSB4X
Melanotan I and Thymosin Beta-4 are noticeably different, with limited direct overlap in their usual biological context. Both are often discussed in Dermatology and aesthetics contexts, while Melanotan I is more of a hormone peptide and Thymosin Beta-4 is better described as a signal peptide and Cytokine peptide. Their biological logic is quite different: Melanotan I is a receptor agonist, whereas Thymosin Beta-4 is a signaling modulator and a protein interaction inhibitor. Melanotan I has a more synthetic analog origin, while Thymosin Beta-4 is closer to natural endogenous background with Melanotan I approved for Research use only and Thymosin Beta-4 in Clinical phase 2. Melanotan I carries d-amino acid substitution features, while Thymosin Beta-4 instead reflects acetylation changes.