Phenformin hydrochloride is a synthetic biguanide compound historically used as an oral antidiabetic agent for the treatment of type 2 diabetes mellitus. It lowers blood glucose levels by inhibiting hepatic gluconeogenesis, enhancing glucose uptake in peripheral tissues, and improving insulin sensitivity in muscle and fat. It was typically prescribed when other agents like sulfonylureas were insufficient, as part of a comprehensive diabetes management plan including diet and exercise. However, due to the high risk of severe lactic acidosis, a potentially fatal complication, phenformin has been withdrawn from clinical use in most countries, including the United States since 1977. This product is intended for laboratory research and pharmaceutical development purposes only and is not approved for human or veterinary therapeutic use. Careful handling and monitoring are required.