Efficacy of Momordica charantia in glycaemic control and insulin resistance among patients with prediabetes and type 2 diabetes. A GRADE-adherent meta-analysis of randomised controlled trials

The prevalence of prediabetes is rising globally, and if untreated, it can lead to a surge in the rate of type 2 diabetes (T2D). Altogether, these conditions are characterised by hyperglycaemia, which promotes cardiovascular complications. Although Momordica has shown promising results in preclinical studies, the existing quantitative synthesis of evidence reports contradictory findings. This study aimed to evaluate the effect of <i>Momordica charantia</i> on fasting blood glucose (FBG), glycated haemoglobin (HbA1c), insulin, homeostatic model of insulin resistance (HOMA-IR), and homeostatic model of β-cell function (HOMA-β) in individuals with prediabetes or T2D. A search for randomised controlled trials was conducted on Scopus, PubMed, and Web of Science until July 19, 2025. Keywords used included <i>M. charantia</i>, bitter melon, prediabetes and diabetes mellitus. The data were presented as standard mean difference (SMD) and 95 % confidence intervals. Twenty-five trials with 34 sub-studies were deemed relevant. The results showed reduced FBG [SMD = -0.46 (-0.73, - 0.18), <i>p</i> = 0.0012] and HbA1c [SMD = -0.57 (-0.83, -0.31), <i>p</i> < 0.0001]. Additionally, there was a significant reduction in the level of insulin [SMD = -0.48 (-0.83, -0.12), <i>p</i> = 0.0082] and HOMA-IR [SMD = -0.52 (-0.95, -0.08), <i>p</i> = 0.0195]. However, no effect was observed on HOMA-β (<i>p</i> = 0.586). The study findings suggest that <i>M. charantia</i> may be used to improve insulin sensitivity and reduce insulin resistance, thereby improving hyperglycaemia in patients with prediabetes and T2D.