Our comprehensive metformin dosage guide and chart breaks down starting doses, maximum limits, and timing recommendations for both immediate-release and extended-release formulations. The table below summarizes the recommended metformin dosage chart for adult patients with diabetes mellitus. All metformin doses should be taken with meals to reduce upset stomach and improve absorption, as noted in the FDA-approved labeling. Metformin alone: At first, 5 milliliters (mL) two times a day, or 8.5 mL once a day with meals. Your doctor may increase your dose if needed until your blood sugar is controlled. NHS medicines information on dosage for metformin, how to take it and what to do if you miss a dose or take too much. This article describes the dosages of metformin, as well as its strengths and how to take it. When taking metformin, always follow the dosage prescribed by your doctor. Detailed Metformin dosage information for adults and children. Includes dosages for Diabetes Type 2; plus renal, liver and dialysis adjustments. Typically, metformin treatment starts with a lower dose, such as 500 milligrams (mg) twice daily or 850 mg once daily. The exact dosage is tailored based on individual health factors under the guidance of a healthcare professional. For adults, the daily metformin dosage should not exceed 2,550 mg.