This study assesses the corrosion inhibitory impact of expired Glibenclamide medication on carbon steel (CS) degrading in 1 M HCl. To assess the corrosion rate, weight loss (WL) and electrochemical methods were employed. The weight loss technique results show that raising the concentration and temperature of glibenclamide improves inhibitory efficiency. The greatest inhibitory efficiency was 84.5% at 300 ppm and 318 K. The substance adsorbs on the CS surface according to the Temkin adsorption isotherm. Electrochemical methods used in this study included potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). The addition of glibenclamide decreased the corrosion current density (icorr) while marginally changing the corrosion potential, indicating that it is a mixed-type inhibitor. The addition of varying doses of glibenclamide to the corrosive medium reduces the double layer capacitance (Cdl) while increasing the charge transfer resistance (Rct). Different surface characterization techniques were employed to assess the compound's influence on the CS surface, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS), were employed. The results support the compound's adsorption onto the CS surface. The molecular inhibitory effect of glibenclamide is demonstrated via quantum chemical calculations and molecular simulations. The results showed that the estimated compound adsorbs to the carbon steel surface.