Background: Diabetes Mellitus (DM) is a metabolic disease that continues to increase globally every year. As cases of DM increase, patient interest in CAM (Complementary and Alternative Medicine) also increases. Consumption together with glibenclamide and bay leaf herbs can cause pharmacokinetic interactions including absorption, distribution, metabolism, and elimination (ADME) which affects the success of therapy. The study aims to determine the effect of bay leaf ethanol extract (EEDS) on blood glucose lowering activity (PKGD), blood drug levels, and pharmacokinetic parameters of glibenclamide in diabetic rats. Methods: Pharmacokinetic interaction analysis was carried out using a validated HPLC method. Pharmacokinetic parameters of glibenclamide were determined based on the relationship between concentration and sampling time using PKSolver. Results: Co-administration of glibenclamide with EEDS increased antidiabetic activity, but was not significant (p > 0.05) with single administration of glibenclamide. Blood levels of glibenclamide increased significantly (p<0.05) with combined glibenclamide administration. In the combination group, the parameters Cmax, AUC0-t, MRT, and T1/2 increased, while the parameters Vd and Cl decreased compared to single glibenclamide administration. Conclusion: Co-administration of glibenclamide with EEDS increased antidiabetic activity, blood levels of glibenclamide, and pharmacokinetic parameters of glibenclamide in diabetic rats. However, its administration did not significantly affect the pharmacological activity in lowering blood glucose levels. Monitoring of drug side effects needs to be done in combination administration because drug levels in the blood increase.