Phlorizin is a competitive inhibitor of SGLT1 (sodium glucose co-transporter 1) and SGLT2 (sodium glucose co-transporter 2); this reduces renal glucose transport, lowering the amount of glucose in the blood. It competitively inhibits the initial rate of α-methyl-D-glucopyranoside (α-MDG) uptake in human COS-1 cells expressing hSGLT1 and hSGLT2 with IC₅₀ values of 400 and 65 nM, respectively. In HEK293T cells expressing human SGLT1 and SGLT2, phlorizin exhibits Ki values of 140 and 11 nM, respectively, at 37°C.