Keyora Skin Systems Nutrition - Elastin Peptide EP-1: The Elastin Identity-to-Skin Research Continuum: From Dermal Elastic Recoil and Four Molecular Identities to Fish-Derived Peptide Characterization and Human Evidence

Background Skin elasticity is a composite biomechanical property involving collagen-mediated tensile resistance, elastin-associated recoil, and hydrated extracellular matrix behavior. However, native tropoelastin, mature cross-linked elastin, composite dermal elastic fibers, and orally administered elastin hydrolysates are distinct biological or nutritional research objects. Failure to distinguish them limits interpretation of ingredient identity and preparation-specific evidence. Methods/Approach This five-chapter narrative synthesis integrates human skin biomechanics, elastin molecular and structural biology, amino acid and cross-link chemistry, fish-derived peptide processing, human peptide-exposure studies, fibroblast experiments, and clinical skin interventions. The Keyora Skin Elastic Recoil Discovery Map, Four-Identity Elastin Decoder, Elastin Molecular Signature Matrix, Elastin Molecular Identity Matrix, and Elastin Identity-to-Skin Research Continuum organize the evidence from tissue function and molecular identity to preparation characterization and human outcomes. Results Human biomechanical studies connect age with lower Cutometer elasticity parameters and document age-associated elastic-fiber remodeling. Elastin molecular identity is defined by characteristic glycine, alanine, valine, and proline distributions, alternating hydrophobic and lysine-associated domains, and lysine-derived cross-links including desmosine and isodesmosine. Mature elastin forms a durable network associated with fibrillin-rich microfibrils, whereas hydrolysis generates peptide populations requiring independent molecular characterization. Fish-source studies demonstrate species-dependent peptide profiles: reported weight-average molecular masses were 719 Da, 714 Da, and 554 Da for grass carp, silver carp, and bighead carp preparations, respectively. Human exposure studies detected circulating Pro-Gly after oral elastin hydrolysate ingestion, with a reported peak near 18 μM at 30 minutes; subsequent plasma analysis identified Pro-Gly and additional elastin-derived peptides. Separate fibroblast experiments reported elastin-synthesis responses to Pro-Gly or fish-derived hydrolysates. Human intervention studies included porcine elastin peptides at 100 or 200 mg/day for eight weeks, fish-derived elastin hydrolysate, and Bonito-derived VGPG Elastin at 100 mg/day for twelve weeks, with improvements in selected elasticity, wrinkle, hydration, or melanin-index endpoints. Interpretation These findings support a preparation-specific research continuum linking source, processing, molecular composition, human exposure, dermal biological response, and measured skin outcomes. They do not establish that different species, tissues, hydrolysis processes, or peptide preparations are interchangeable, nor that circulating peptide detection proves direct incorporation into dermal elastic fibers. Evidence Alignment The Keyora frameworks distinguish structural biology, analytical ingredient identity, human pharmacokinetics, in-vitro responses, and clinical outcomes. The declared Keyora ingredient, tilapia-derived elastin peptide at 20 mg per two-tablet serving, should therefore be compared with published preparations only after its anatomical source, processing, peptide distribution, and sequence profile are characterized. This framework supports evidence-bounded interpretation and preparation-matched research rather than extrapolation from unlike materials.