Tetrapeptide-30 is a skin-brightening peptide consisting of four amino acids. Tetrapeptide-30 can act as a tyrosinase inhibitor, lightening hyperpigmentation and evening out skin tone by reducing the amount of tyrosinase and inhibiting melanocyte activation[1].
Tetrapeptide-30 (0-10 μg/mL, 24 h) can effectively reduce UVB-induced gene expression of IL-6, TNF-α and POMC (proopiomelanocorticotropin), and also decreased IL-8 gene expression in a dose-dependent manner[1].Tetrapeptide-30 (PKEK) is highly hydrophilic and has good skin penetration in microemulsion[2].
[1]. Alessandra Marini, et al. Modulation of skin pigmentation by the tetrapeptide PKEK: in vitro and in vivo evidence for skin whitening effects. Exp Dermatol. 2012 Feb;21(2):140-6.
[2]. Reinhard H H Neubert, et al. Dermal peptide delivery using enhancer moleculs and colloidal carrier systems. Part II: Tetrapeptide PKEK. Eur J Pharm Biopharm. 2018 Mar;124:28-33.