From the Guidelines
Metformin is typically started at a dose of 500 mg once or twice daily for type 2 diabetes, with gradual increases as needed, as recommended by the most recent guidelines 1. The usual maintenance dose ranges from 1,000 to 2,000 mg daily, divided into two or three doses, with a maximum recommended dose of 2,550 mg per day. Starting with a lower dose and taking it with meals helps reduce gastrointestinal side effects like nausea, diarrhea, and stomach discomfort, which are common initially but often improve over time. Extended-release formulations are available for once-daily dosing, which may improve adherence and reduce side effects. Metformin works by decreasing glucose production in the liver, improving insulin sensitivity in muscles, and reducing intestinal absorption of glucose. Kidney function should be monitored as metformin is contraindicated in severe kidney disease. Dose adjustments may be necessary based on blood glucose control, tolerance, and kidney function. Regular monitoring of blood glucose levels and HbA1c is important to assess effectiveness and adjust treatment as needed, as supported by recent studies 1. Some key points to consider when prescribing metformin include:
- Starting with a low dose and gradually increasing as needed to minimize gastrointestinal side effects
- Monitoring kidney function and adjusting the dose accordingly
- Considering the use of extended-release formulations for once-daily dosing
- Regularly monitoring blood glucose levels and HbA1c to assess effectiveness and adjust treatment as needed. It is also important to note that metformin is the preferred initial pharmacologic agent for the treatment of type 2 diabetes, and it should be continued as long as it is tolerated and not contraindicated, with other agents added to metformin as needed 1.
From the FDA Drug Label
The extent of metformin absorption (as measured by AUC) from metformin hydrochloride extended-release tablets at a 2000 mg once-daily dose is similar to the same total daily dose administered as metformin hydrochloride tablets 1000 mg twice daily
The usual dose of metformin for a person with type 2 diabetes is 1000 mg to 2000 mg per day, given in divided doses, such as:
- 500 mg twice daily
- 850 mg twice or three times daily
- 1000 mg once or twice daily
- 2000 mg once daily (extended-release tablets) 2
From the Research
Metformin Dosage for Type 2 Diabetes
- The provided studies do not specify the exact dosage of metformin for type 2 diabetes patients 3, 4, 5, 6, 7.
- However, the studies discuss the effectiveness of metformin as a first-line therapy for type 2 diabetes, often in combination with other medications such as pioglitazone, sitagliptin, or dapagliflozin 4, 5, 6, 7.
- One study mentions that patients took pioglitazone 15 mg plus metformin 850 mg twice a day, but this is not a direct answer to the question of typical metformin dosage 6.
- Another study compares the effects of adding sitagliptin or metformin to pioglitazone monotherapy, with metformin dosed at 850 mg twice a day, but again, this does not provide a general answer to the question of typical metformin dosage for type 2 diabetes patients 6.
Combination Therapies
- The studies suggest that metformin can be effectively combined with other medications, such as pioglitazone, sitagliptin, or dapagliflozin, to improve glycemic control in type 2 diabetes patients 5, 6, 7.
- These combination therapies can have various effects on body weight, glycemic control, beta-cell function, insulin resistance, and inflammatory state parameters 6, 7.