Any substance used to reduce hyperglycemia or treat disorders associated with diabetes. Based on their mechanism of action, this class of agents can be classified to the following groups: directly acting insulomimetics, which activates insulin receptors; indirectly acting insulinomimetics, which increase insulin release such as sulfonylureas or which potentiate the effect of insulin such as metformin; those act directly on the metabolism of glucose such as inhibitors of glucosidases and inhibitors of aldose reductase.