The medication comes in tablet form and is available in various strengths, including:
- 500-mg metformin tablets
- 850-mg metformin tablets
- 1000-mg metformin tablets.
A long-acting form of metformin is also available and comes in the following strengths:
The recommended starting metformin dosage for children ages 10 to 16 is 500 mg twice a day. For people over the age of 17, the usual starting dose is 500 mg twice daily or 850 mg once daily.
With the long-acting form of metformin, the starting dose is 500 mg once daily, and the maximum dose is metformin ER 2000 mg once daily (or metformin ER 1000 mg twice daily).
(Click Metformin Dosing for more information about metformin 1000-mg tablets, for dosing guidelines for people who also take insulin, and for suggestions on when and how to take this medication.)