HB SR 500 Tablet contains Metformin 500 mg, an oral antihyperglycemic agent primarily used in the management of type 2 diabetes mellitus. Metformin belongs to the biguanide class and acts by decreasing hepatic glucose production, reducing intestinal absorption of glucose, and improving insulin sensitivity by increasing peripheral glucose uptake and utilization. This multifaceted mechanism helps to lower both fasting and postprandial blood glucose levels without causing significant hypoglycemia when used as monotherapy. HB SR 500 is formulated as a sustained-release tablet to provide a gradual release of the active ingredient, enhancing patient compliance by reducing dosing frequency and minimizing gastrointestinal side effects commonly associated with immediate-release formulations. It is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes, particularly in overweight patients or those with insulin resistance. The tablet should be administered with meals to improve gastrointestinal tolerability. Caution is advised in patients with renal impairment, hepatic dysfunction, or conditions predisposing to hypoxia, as these may increase the risk of lactic acidosis, a rare but serious adverse effect. Regular monitoring of renal function and glycemic parameters is recommended during therapy. HB SR 500 should be used under medical supervision as part of a comprehensive diabetes management plan.