Extracts of G. sylvestre given to patients with type I diabetes on insulin therapy reduces insulin requirements and fasting blood sugar levels, and improves blood sugar control. In a study of type II diabetics, gyrmnema extract given along with oral hypoglycemic drugs was shown to improve blood sugar control and to either lead to discontinuation of the medicine or a significantly reduced dosage. It is interesting to note that gymnema extract given to healthy volunteers does not produce any blood sugar-lowering, or hypoglycemic, effects.