Objectives: to examine lipoic acid or glutathione(GSH)-mediated protection against cytotoxicity following cisplatin exposure in HEI-OC1 auditory cell, and to measure the potential to scavenge reactive oxygen species (ROS) by lipoic acid and GSH. This study also compare the protective effect of lipoic acid and GSH, and discuss the determination of preventive doses or therapeutic doses. Methods:HEI-OC1 cells were pretreated with lipoic acid or GSH for 24 h and then exposed to 15 μM cisplatin for 48 h. Resulting cytotoxicity was measured by the cell counting kit-8, and intracellular ROS was measured using flow cytometry. Protective effect or anti-ROS effect of lipoic acid and GSH were compared each other. Result:Pretreatment with lipoic acid 100 μM and GSH 1 mM protected HEI-OC1 auditory cells against cisplatin-induced cytotoxicity and significantly reduced a cisplatin-induced increase in ROS. Lipoic acid showed a significantly more effective protection to cisplatin-induced ototoxicity compared with GSH (85.4% vs. 73.1% cell viability). Both lipoic acid and GSH showed different concentrations of maximal protective effect on normal condition and cisplatin-induced cytotoxic condition. It may suggest that preventive doses or therapeutic doses for harmful conditions are quite different in two drugs, and need careful drug dose adjustment. Conclusion:This is a challenging study for comparison of the protective effects of the protective effect of lipoic acid and GSH against cisplatin-induced ototoxicity in an auditory cell line. Lipoic acid and GSH showed a significant protective effect against cisplatin, and lipoic acid seems to be superior to GSH. Lipoic acid and GSH showed different concentrations of maximal protective effect on normal condition and harmful condition, which suggest the need of drug dose adjustment according to therapeutic purposes.