Gentisic acid: It is derived from Gentian roots and is a safe and effective topical skin lightening agent. Its alkyl ester, especially methyl gentisate is highly effective and less cytotoxic than hydroquinone. In a comparative in vitro study by Curto et al, 4 depigmenting agents, namely hydroquinone, kojic acid, arbutin, magnesium ascorbyl phosphate and synthetic esters of gentisic acid were studied for their tyrosinase inhibitory effects where mammalian melanocyte cell cultures and cell-free extracts were used. The study demonstrated that the smaller esters of gentisic acid shared an ability to inhibit melanogenesis without cytotoxicity and mutagenesis. [10]