Pseudo-C2-symmetric irreversible inhibitors of HIV-1 protease containing cisepoxide were designed, synthesized, and kinetically characterized. Introduction of a Gly residue into P1' of the inactivators yielded strong time-dependent irreversible ones with kina/Ki ranging from 1.5×10⁸ to 3.4×10⁵ M⁻¹min⁻¹.