Keyora Skin Systems Nutrition - Collagen Tripeptides EP-9: The Preparation-Dose-Endpoint Alignment Matrix: Molecular Identity, Clinical Duration, and Human Skin Outcomes

Background Oral collagen supplements are frequently compared by labeled milligrams, although hydrolysate mass does not specify source tissue, peptide composition, systemic exposure, or clinical efficacy. Skin hydration, transepidermal water loss (TEWL), elasticity, and facial wrinkles represent distinct outcomes with different measurements and observation windows. Higher nominal intake cannot therefore be equated with greater clinical benefit. Objective and Scientific Framework This narrative evidence synthesis develops the Keyora Preparation-Dose-Endpoint Alignment Matrix, operationalized through the Preparation-Dose-Duration-Endpoint (PDDE) Framework. Its five chapters integrate molecular dose identity, human response timing, population fit and trial reliability, cross-trial clinical evidence, and a decision pathway for direct product evaluation. Mechanistic Foundations Enzymatic hydrolysis generates mixtures distinguished by source tissue, molecular-weight distributions, dipeptide and tripeptide fractions, and individual sequences. Human pharmacokinetic investigations, including Iwai (2005), detected hydroxyproline-containing peptides after ingestion, with peptide-form hydroxyproline concentrations peaking approximately 1-2 hours postdose. Detection of Pro-Hyp and Gly-Pro-Hyp establishes systemic exposure but not dermal efficacy. Filaggrin-derived natural moisturizing factors contribute to stratum corneum water retention; epidermal barrier integrity affects TEWL, while dermal structural networks contribute to elastic recovery. Experimental and Human Evidence In a twelve-week randomized trial of 1 g/day sutchi-catfish-skin peptides, Kim (2018) reported cheek hydration of 61.14 versus 53.02 arbitrary units (p = 0.003); Cutometer R2 and R5 improved significantly, whereas R7 did not. Lee (2023) reported improved facial hydration by week four (p < 0.001) and forearm desquamation (p = 0.017) with 1.65 g/day CPNS. Tak (2021) found a significant weather-adjusted TEWL difference at week twelve with 1 g/day tilapia-skin tripeptides (p = 0.024). Proksch (2014) reported improved eight-week elasticity with 2.5 and 5 g/day; a separate 2.5 g/day trial found 20.1% lower periocular wrinkle volume versus placebo. Asserin (2015) observed moisture increases of 12% and 28% with fish and porcine peptides at 10 g/day, respectively, without a significant TEWL difference. Integrated Scientific Interpretation The PDDE framework preserves preparation, comparator, baseline phenotype, dose, observation visit, measurement instrument, effect estimate, and research quality in every comparison. Keyora declares 1,500 mg of tilapia-scale hydrolysed collagen powder per two tablets, a 30% total tripeptide fraction, and a supplier-reported mean molecular weight of approximately 459 Da. The fraction corresponds conditionally to 450 mg of aggregate tripeptides, not a quantified Gly-Pro-Hyp dose. Evidence Boundaries and Conclusions A 2025 synthesis of 23 randomized trials (1,474 participants) found no significant benefits in higher-quality or non-industry-funded subgroups. A 2026 synthesis of 35 trials (2,534 participants) reported favorable pooled hydration (SMD 0.44) and TEWL (SMD -0.39) effects, but elasticity depended on sensitivity analysis and wrinkle findings lacked robustness after outlier exclusion. Published results cannot establish efficacy for the untested finished Keyora formulation. The matrix instead supports transparent evidence matching and design of a preparation-specific randomized trial.