This study evaluated the antidiabetic effects of two herbal formulations, Formulation A and Formulation B, in a preclinical animal model. The formulations were selected based on their traditional use in managing diabetes, with Momordica charantia and Trigonella foenum-graecum (Formulation A) known for their hypoglycemic effects, and Ocimum sanctum and Curcuma longa (Formulation B) recognized for their antioxidant and insulin-sensitizing properties. Both formulations were assessed for their impact on glycemic control, pancreatic function, and oxidative stress. Diabetes was induced in adult male Wistar rats using a high-fat diet and streptozotocin (STZ). The rats were divided into three groups: a control group, a group receiving Formulation A dosage (200 mg/kg/day for 8 weeks), and a group receiving Formulation B dosage (250 mg/kg/day for 10 weeks). Key diabetic parameters, pancreatic function, and oxidative stress markers were measured before and after treatment. Formulation B showed superior results, with a 22.2% reduction in fasting blood glucose, a 30% decrease in postprandial glucose, and a 52.2% increase in insulin sensitivity. Whereas Formulation A resulted reduction in fasting blood glucose and increase in insulin levels, alongside improvements in pancreatic islet area and β-cell density. Additionally, Formulation B significantly reduced oxidative stress markers and enhanced pancreatic health more effectively than Formulation A. Both formulations demonstrated efficacy in managing diabetes, but Formulation B proved to be more effective overall, offering enhanced glycemic control, improved pancreatic function, and greater reduction in oxidative stress.