Escitalopram-d4 (oxalate) is deuterium labeled Escitalopram (oxalate). Escitalopram ((S)-Citalopram) oxalate, the S-enantiomer of racemic Citalopram, is a selective serotonin reuptake inhibitor (SSRI) with a Ki of 0.89 nM. Escitalopram oxalate has ∼30 fold higher binding affinity than its R(-)-enantiomer and shows selectivity over both dopamine transporter (DAT) and norepinephrine transporter (NET). Escitalopram oxalate is an antidepressant for the research of major depression[1][2].