Overall, Metformin reduces blood sugar levels can rise too high. Metformin comes as a tablet and an extended-release tablet to take by mouth. Most benefit from it. Metformin helps to control the amount of sugar that your liver makes and that your stomach absorbs. Metformin comes as a tablet and an extended-release tablet to take by mouth. Metformin belongs to the class of drugs known as biguanides. Metformin comes as a tablet and an extended-release tablet to take by mouth. Glucophage should be taken with meals.