KL1333, a derivative of β-lapachone, is an orally available NAD+ modulator. KL1333 reacts with NAD(P)H:quinone oxidoreductase 1 (NQO1) as a substrate, resulting in increases in intracellular NAD+ levels via NADH oxidation. KL1333 improves energy metabolism and mitochondrial dysfunction in MELAS fibroblasts. KL1333 protects against Cisplatin-induced ototoxicity in mouse cochlear cultures .