Lipid nanocapsules (LNCs) are nanovectors that permit the encapsulation of lipophilic active drugs allowing a better targeting, while decreasing the side effects of the active drug. LNCs represent a real interest in the treatment of various diseases including infections and cancers [1, 2] , these pathologies imply a chronic treatment. Therefore both acute and chronic toxicity had to be assessed. Moreover, LNCs partially accumulate in the liver after in vivo injections regardless of size and composition [3, 4]. The objective of the study is to determine the best LNCs formulation without hepatic side effetcs and with a high biocompatibility. To this end, HepG2 and HepaRG liver cell lines were exposed to various LNCs in acute and chronic conditions in order to answer these questions: (i) is there a composition effect? (ii) a size effect? (iii) chronic effects after repeated exposure?