Our study aims to show the illicit use of certain ingredients in the composition of cosmetic depigmenting products. For this purpose, a method of identification and quantification using High Performance Liquid Chromatography coupled to mass spectrometry (CLHP/SM) has been developed, allowing the characterization and rapid determination of various regulated and/or prohibited molecules. Two molecules have been studied: hydroquinone and kojic acid, which are the most regulated substances used. These molecules used commonly in "whitening" cosmetic products with a high incorporation percentage generating important side effects. This improper use is now at the origin of a real public health concern called voluntary depigmentation. Our results show that the International Nomenclature of Cosmetic Ingredients (INCI) composition of some cosmetics, as given by the manufacturers, can be misleading. Indeed, (i) hydroquinone presence is clearly alleged in three tested produ cts when hydroquinone was found in five products, (ii) five of seven tested products contain hydroquinone in higher percentage than mentioned, (iii) similarly three cosmetics contain both hydroquinone and kojic acid whereas the latter was stated in the composition of only two of them. Thus, the development of this new technique enables the verification of the compositions claimed by manufacturers and can contribute to protecting the consumers' health of cosmetic products. (C) 2017 Societe Francaise de Toxicologie Analytique. Published by Elsevier Masson SAS. All rights reserved.