From the Guidelines
The recommended metformin dose for weight loss is 1500-2000 mg per day, usually divided into two or three doses, as doses greater than 1500 mg are associated with the greatest weight loss 1. To achieve this dose, start with a low dose of 500 mg once or twice daily with meals, and gradually increase over several weeks to the full dose to minimize gastrointestinal side effects, as suggested by the American Diabetes Association and the European Association for the Study of Diabetes 1. For best results:
- Take metformin with meals to reduce stomach upset
- Stay well-hydrated
- Combine with a reduced-calorie diet and regular exercise
- Continue for at least 3-6 months to see significant effects Metformin aids weight loss by reducing appetite, decreasing sugar absorption in the intestines, and improving insulin sensitivity, with pleiotropic effects including decreased inflammation, increased insulin and leptin sensitivity, and decreased hunger and ghrelin levels, especially with twice-daily dosing 1. It's most effective in people with insulin resistance or prediabetes, and while not FDA-approved specifically for weight loss, it's sometimes prescribed off-label for this purpose, particularly in individuals with or at risk for type 2 diabetes. Monitor for side effects like nausea, diarrhea, and abdominal discomfort, and consult your doctor before starting metformin, as it's not suitable for everyone and requires regular medical supervision.
From the FDA Drug Label
2 DOSAGE AND ADMINISTRATION
- 1 Adult Dosage Metformin Hydrochloride Tablets The recommended starting dose of metformin hydrochloride tablets are 500 mg orally twice a day or 850 mg once a day, given with meals. Increase the dose in increments of 500 mg weekly or 850 mg every 2 weeks on the basis of glycemic control and tolerability, up to a maximum dose of 2550 mg per day, given in divided doses.
The FDA drug label does not answer the question.
From the Research
Metformin Dose for Weight Loss
- The exact dose of metformin for weight loss is not explicitly stated in the provided studies, but the daily doses used in the studies ranged from 500-2500 mg 2.
- A study on the combination therapy of metformin and fluoxetine for weight reduction used a dose of 500 mg of metformin three times daily 3.
- Another study found that metformin treatment significantly reduced BMI in obesity patients, but the dose was not specified 4.
- A systematic review of metformin treatment for weight loss in children and adults found that the effects of metformin on weight/BMI vary, but did not provide a specific dose 5.
- A review of the effects of metformin on weight loss, cardiovascular health, and longevity discussed the molecular mechanisms of metformin, but did not provide a specific dose for weight loss 6.
Subgroup Analysis
- A subgroup analysis of metformin treatment found that BMI in the high dose group decreased by 1.01 units, but the exact dose was not specified 4.
- The same study found that metformin treatment significantly reduced BMI in obesity patients with a BMI >35kg/m2, but the dose was not specified 4.