Metformin is a biguanide antihyperglycemic agent and first-line pharmacotherapy used in the management of type II diabetes.[L12207,A176173] Metformin is considered an antihyperglycemic drug because it lowers blood glucose concentrations in type II diabetes without causing hypoglycemia. It is commonly described as an "insulin sensitizer", leading to a decrease in insulin resistance and a clinically significant reduction of plasma fasting insulin levels.[A176173] Another well-known benefit of this drug is modest weight loss, making it an effective choice for obese patients type II diabetes.[A36559] Metformin was first approved in Canada in 1972,[A36552] and received subsequent FDA approval in the US in 1995.[L12207]