Diabetes mellitus, particularly type 2 diabetes (T2DM), has emerged as a major global health concern with over 800 million adults currently affected. This alarming increase more than a fourfold rise since 1990 underscores the urgent need for disease management and prevention. While pharmaceutical treatments, such as insulin and oral hypoglycemic agents are widely used, there is growing interest in herbal and natural therapies due to their affordability, availability and reduced incidence of side effects. Among these, species of the genus Gymnema have attracted considerable attention for their potent anti-diabetic properties. Gymnema sylvestre, the well-researched species has been traditionally used in Ayurvedic medicine for its ability to reduce sugar absorption, enhance insulin secretion and regenerate pancreatic beta cells. The presence of gymnemic acids, saponins and flavonoids contributes to its hypoglycemic effects. However, beyond G. sylvestre, several lesser-known Gymnema species, such as G. montanum, G. latifolium and G. yunnanense contain bioactive compounds with potential anti-diabetic effects yet remain largely unexplored. This review provides a comprehensive analysis of both well-established and lesser-known Gymnema species. It emphasizes the critical need for further pharmacological and clinical investigations to fully unlock the therapeutic benefits of these underutilized species.
