Influence of Oral Collagen Peptides on Skin Biophysical Properties in Humans: A Narrative Review

The skin not only provides protection and sensory functions for the body, but healthy skin also enhances self-esteem. Moreover, altered cutaneous function contributes to the development of extracutaneous disorders. Therefore, great efforts have been made to identify agents and natural ingredients that are safe and effective to improve cutaneous function. In this narrative review, we searched PubMed and Google Scholar for literature on the effects of collagen peptides on skin biophysical properties. Studies have demonstrated that oral peptide improves several cutaneous functions, including stratum corneum hydration, epidermal permeability barrier, elasticity, firmness and roughness, in part via upregulation of keratinocyte differentiation, epidermal lipid synthesis, hyaluronic acid and collagen synthesis, and inhibition of inflammation, in addition to stimulation of fibroblast proliferation and aquaporin 3 expression. However, the heterogeneity among the included studies and their limited sample sizes preclude firm conclusions regarding the benefits of oral collagen peptides for cutaneous biophysical properties. Further research is needed to assess the efficacy of different collagen peptide sources and types across individual skin biophysical outcomes.