In the present study, hypoglycemic and anti-obesity effects of a mixed Momordica charantia water extract (MC): platycodin (PL) (1:4) formula (MMP) were observed in obese db/db mice at doses of 10, 50, 100 and 200 mg/kg; these effects were also seen with MC alone and PL alone at 200 mg/kg. The effects were compared to those of metformin, which improves insulin resistance and inhibits obesity at 250 mg/kg. The test agents were administered orally, to db/m and db/db mice, once a day for 28 days. Mice were classified into nine groups (7 mice per group) according to body weight and fasting blood glucose level one day before dosing began. After 28 days, changes in body weight, blood glucose, epididymal fat, serum leptin, adiponectin, adipose adiponectin, and liver triglycerides were recorded. Prior to test agent administration, db/db mice showed marked obesity compared to db/m mice (normal littermates) with severe hyperglycemia. Epididymal fat, serum leptin and liver triglycerides in obese controls were significantly increased compared to those of intact controls (p<0.01), whereas serum adiponectin and adipose adiponectin were significantly decreased in the obese group (p<0.01). However, these obesity- and hyperglycemia-related changes were dramatically and dose-dependently inhibited by MMP treatment, and more favorable outcomes were seen in the MMP groups compared to the MC alone and PL alone groups. Furthermore, MMP at 50 mg/kg was associated with similarly beneficial outcomes regarding diabetes and diabetes-related obesity compared to 200 mg/kg MC alone or PL alone, and MMP at 100 mg/kg showed similar efficacy to 250 mg/kg metformin. Based on the present results, MMP has synergic and beneficial effects on diabetes and diabetes-related obesity. Therefore, MMP shows promise as a novel complementary approach for managing diabetes and diabetic obesity at a reasonable dosage.