Novel glycerin compounds (NGCs) were developed which generated new reaction products, endoperoxide derivatives. NGCs have been reported to exhibit various biological effects. In addition to their deodorizing, disinfecting and antiviral effects, NGCs were found to promote wound healing in the skin by stimulating epithelial growth and regeneration with the synthesis of extracellular matrix such as hyaluronic acid. In this study, in order to clarify the effects of NGCs on normal human skin, we quantified the mRNA gene expression of heme oxygenase-1 (HO-1) and DAD(P)H quinone dehydrogenase 1 (NQO-1) as antioxidant factors by PR-PCR and the protein content of intracellular glutathione (GSH) using a culture system of normal human epidermal keratinocyte. Moreover, gene expression of factors related to skin barrier functions (involucrin (INV), filaggrin (FLG), and serine palmitoyl transferase (SPT)) was examined to clarify the effects of NGCs on epidermal cell differentiation. Our results showed that NGCs enhanced expression of HO-1, NQO-1 mRNA and GSH protein in a concentration-dependent manner from 20 ppm after 24 h of stimulation. These results suggest that the oxidative property of NGCs activates Nrf2 (NF-E2-related factor 2) transcription factor, which is a biological defense sensor, and induces the expression of antioxidant factors. Since their expression was caused by oxidative stimulation at low concentrations of NGCs, it was strongly suggested that their hormesis effect would be working protectively for the skin. Consistent with this, the expression of INV, FLG, and SPT genes also increased at low concentrations of NGCs: FLG showed a threefold increase compared to the control group. These results suggest that NGCs promote epidermal cell differentiation and have positive effects on skin barrier functions. Mild oxidative stimulation of NGC may lead to healthy skin through hormesis effect. We are currently conducting detailed analysis of the effects of NGCs using three-dimensional cultures of human epidermis.