N-acetyl glucosamine (NAG) has been shown to be effective in reducing the appearanceof hyperpigmented spots. From published in vitromechanistic testing, glucosamineinhibits enzymatic glycosylation, a required processing step in converting inactivehuman pro-tyrosinase to the active tyrosinase, a key enzyme in the production ofmelanin. There is also published literature discussing the anti-inflammatory andantioxidant properties of glucosamine compounds. To identify additional mechanisms bywhich NAG might affect melanin production, an in vitrogenomics experiment wasconducted in SkinEthic skin equivalent cultures, which were topically dosed with NAGvs. a vehicle control. Relative to vehicle, NAG reduced melanin production, and theexpression of several pigmentation-relevant genes were affected (down-regulated orup-regulated) by NAG treatment. Thus, there are several mechanisms that may beoperative in the observed pigmentation effects.