Saquinavir is a decahydroisoquinoline-based, selective inhibitor of aspartic protease encoded by HIV with an IC50 range of 0.5-6.0 nM and IC90 range of 6.0-30.0 nM. [1] Binding inhibition constants for saquinavir against HIV-1 and HIV-2 are 0.12 nM and
Antiviral potency of saquinavir were shown in JM cells infected with HIV-1 strain GB8 with a IC50 of 2.5 nM. [2] Similarly, and IC50 of 2 nM was obtained against HIV-1 (strain RF) in C8166 cells.

Saquinavir was shown to be a substrate for P-glycoprotein transporter protein, affecting intracellular concentrations and bioavailability. [3]