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, TB-500 is studied for enhancing musculoskeletal and cardiac repair, wound healing, and promoting cell migration and differentiation via actin cytoskeleton remodeling21255.
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, TB-500 is a synthetic peptide comprising the LKKTETQ actin-binding motif of thymosin beta-4 that binds G-actin, sequesters actin monomers, and promotes cell migration, angiogenesis, and tissue repair1255.
Melanotan I
POMC
TB-500
TMSB4X
Melanotan I and TB-500 are noticeably different, with limited direct overlap in their usual biological context. Their typical research and application settings separate fairly clearly: Melanotan I is more often discussed in the realm of Dermatology and aesthetics, whereas TB-500 is more often associated with the realm of Musculoskeletal health and Cardiovascular health. Their biological logic is quite different: Melanotan I is a receptor agonist, whereas TB-500 is a signaling modulator and a growth factor mimetic. Both are synthetic in origin with Melanotan I approved for Research use only and TB-500 in Preclinical development. Melanotan I incorporates d-amino acid substitution features that are not part of TB-500.