Hyperglycemia is a condition of high blood sugar level commonly referred to as diabetes mellitus. It is caused by either impaired insulin secretion or resistance to insulin by various tissues. Various herbs were used in the past to treat high blood sugar level as they were antihyperglycemic and did not show any side effect. Out of these herbs, a tropical plant Momordica charantia, commonly known as bitter melon belongs to family Cucurbitaceae showed antidiabetic activity and is a common source of vitamins, antihyperglycemic agents, antioxidants and minerals. All of these compounds have pharmacological properties and are used to treat various types of disorders mostly diabetic disorders. It contains steroidal glycoside charantin that is also known as momocharin which was extracted from seeds, fruits and leaves of M. charantia. M. charantia is a well-studied and the most important plant for antidiabetic effect. M. charantia is a herb and member of class Violes. It has been used as a vegetable and is considered as remedy for diabetic patients. It is mostly grown in Asia, South America and East Africa. Leaves, seeds, flowers and mostly fruits are used by human. M. charantia has been reported that it acts against diabetes mellitus through pancreatic and extra-pancreatic mechanisms. Various mechanisms have been reported about its hypoglycemic effect to control glucose level either by promotion of glucose uptake by muscles or increasing insulin sensitivity.