This paper deals with the extensive investigation of molecular interaction between third generation cephalosporin antibiotic, Cefpodoxime Acid (CA) and Human Mixtard Insulin (HMI) in an aqueous medium through ultrasonic, dilute solution viscometric (DSV) and spectral [UV–vis, Attenuated total reflection (ATR)–FT IR] methods at various blend compositions of the drug and insulin at three different (303 K, 310 K and 313 K) temperatures. This is an attempt to unravel the possibility of drug induced hypoglycemic effect. The existence of solute–solute interaction in aqueous solutions of CA and HMI is established from the variation of ultrasonic velocity and other acoustical parameters with blend composition. DSV method is used to confirm the range of blend composition at which the molecular interaction is significant. The conclusions drawn from ultrasonic and DSV methods are further established by the UV–vis and ATR- FT IR spectral studies of ternary mixtures at different blend compositions. Further, the existing interactions suggest the possibility of cefpodoxime acid induced hypoglycemia which is discussed based on the structural aspects of the two components.