Abstract
INTRODUCTION: Collagen is a fundamental component of the skin's extracellular matrix, yet its low oral bioavailability raises questions about its efficacy in improving skin health. Bioactive collagen peptides (BCP), as hydrolyzed forms of collagen, offer enhanced absorption and functionality. However, evidence regarding their sustained effects and the impact of molecular weight distribution is still limited. AIM: To evaluate the long-term effects of BCP supplementation on skin hydration, elasticity, and dermal structure, and to explore the relationship between molecular properties of BCP and skin outcomes. METHODS: A randomized, double-blind, placebo-controlled trial was conducted involving 77 healthy female participants aged. Subjects received either 5000 mg/day of BCP or placebo for 12 weeks, followed by a 4-week washout period. Skin parameters-including hydration, transepidermal water loss (TEWL), elasticity, and dermal/epidermal thickness and density-were measured at baseline, Week 8, Week 12, and Week 16 using non-invasive techniques. RESULTS: BCP significantly improved dermal density, hydration, and TEWL compared to placebo after 12 weeks (p < 0.05). These improvements were maintained during the washout period. Dermal thickness also increased in the BCP group, while no significant changes were noted in the epidermis. CONCLUSIONS: Twelve weeks of oral BCP supplementation, followed by a 4-week washout, produced lasting improvements in skin hydration, firmness, and dermal structure. These effects are likely linked to the BCP's high hydroxyproline content and low molecular weight distribution, supporting its use in anti-aging skincare strategies. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT06847035.