Bioactive peptides in cosmetic formulations: Review of current in vitro and ex vivo evidence

Bioactive peptides are increasingly employed in cosmetic products and these are generically known as cosmetic peptides. This review aims to provide an update on current information related to commercially available cosmetic peptides, and the in vitro and ex vivo evidence for their potential biological effects. A total of 102 commercially available cosmetic peptides were identified. The majority of these peptides are inspired by molecules already found in the human body, including sequences from extracellular matrix molecules, also known as matrikines. Cosmetic peptides are produced either through chemical synthesis or via biotechnological processes. Their claimed biological activities include signaling to increase collagen and hyaluronic acid production, modulation of pigmentation, maintenance of a healthy skin microbiome, antioxidant activity and cellular defense, immunomodulation, neurotransmitter inhibition, enzyme activity inhibition and trace mineral carriers. The primary structure and current scientific evidence for the bioactivities of these peptides are presented and discussed. The review highlights the diverse methodological approaches used and the outcomes measured in the assessment of cosmetic peptide efficacy. Overall, a large range of cosmetic peptides are commercially available whose efficacy is supported by divergent levels of in vitro and ex vivo data.