Atazanavir-d9 is the deuterium labeled Atazanavir. Atazanavir (BMS-232632), a highly selective HIV-1 protease inhibitor, is the first protease inhibitor approved for once-daily administration[1]. Atazanavir (BMS-232632) is a substrate and inhibitor of CYP3A4, and an inhibitor and inducer of P-glycoprotein (P-gp)[2]. Atazanavir is also a SARS-CoV 3CLpro inhibitor with an IC50 of 3.49 µM[3].