Siramesine is an agonist for sigma-2 (σ2) receptor. It is selective for σ2 over σ1 with IC₅₀ values of 0.12 nM and 17 nM respectively. It shows potent anxiolytic-like effects in rodents. The minimal effective dose (MED) is 0.18 nmol/kg (0.1 microg/kg) and 0.00018 nmol/kg (0.1 ng/kg) in rats and mice respectively. It (20-30 µM) induces cell death in HaCaT, Hsc-4, HeLa, MCF-7, SH-SY5Y and glioblastoma cell lines. Siramesine shows anti-viral activity againt SARS-CoV-2 infection in the Vero E6 cell line in an immunofluorescence-based assay (detecting the viral NP protein).