Butyl isobutyl phthalate exhibits significant, concentration-dependent inhibitory activity against α-glucosidase with an IC ₅₀ value of 38 μM.

Butyl isobutyl phthalate (intragastric administration; 25, 50 or 100 mg/kg; 3 days) results in a more significant reduction in the blood glucose level, with the concentration of blood glucose being 11.50, 8.60 and 6.50 mM, respectively.