Tamoxifen citrate is a nonsteroidal antiestrogen. Chemically, tamoxifen is the trans-isomer of a triphenylethylene derivative. The chemical name is (Z)2-[4-(1,2-diphenyl-1-butenyl) phenoxy]-N, N-dimethylethanamine 2-hydroxy-1,2,3- propanetricarboxylate (1:1).

Tamoxifen citrate has a molecular weight of 563.62, the pKa' is 8.85, the equilibrium solubility in water at 37ˇăC is 0.5 mg/ml and in 0.02 N HCl at 37ˇăC, it is 0.2 mg/ml.