Hypoglycemic effect of bitter melon compared with metformin in newly diagnosed type 2 diabetes patients

Abstract Ethnopharmacological relevance Bitter melon ( Momordica charantia L.) has been widely used as an traditional medicine treatment for diabetic patients in Asia. In vitro and animal studies suggested its hypoglycemic activity, but limited human studies are available to support its use. Aim of study This study was conducted to assess the efficacy and safety of three doses of bitter melon compared with metformin. Materials and methods This is a 4-week, multicenter, randomized, double-blind, active-control trial. Patients were randomized into 4 groups to receive bitter melon 500 mg/day, 1000 mg/day, and 2000 mg/day or metformin 1000 mg/day. All patients were followed for 4 weeks. Results There was a significant decline in fructosamine at week 4 of the metformin group (−16.8; 95% CI, −31.2, −2.4 μmol/L) and the bitter melon 2000 mg/day group (−10.2; 95% CI, −19.1, −1.3 μmol/L). Bitter melon 500 and 1000 mg/day did not significantly decrease fructosamine levels (−3.5; 95% CI −11.7, 4.6 and −10.3; 95% CI −22.7, 2.2 μmol/L, respectively). Conclusions Bitter melon had a modest hypoglycemic effect and significantly reduced fructosamine levels from baseline among patients with type 2 diabetes who received 2000 mg/day. However, the hypoglycemic effect of bitter melon was less than metformin 1000 mg/day.