From the Guidelines
Metformin 500mg ER can be considered for weight loss in adults, with approximately 3% weight loss and 25-50% of participants achieving at least 5% weight loss, as reported in a 2023 review published in JAMA 1. When using metformin for weight loss, it is essential to note that doses greater than 1500 mg are associated with the greatest weight loss, according to the same review 1. Key points to consider when prescribing metformin for weight loss include:
- Metformin's pleiotropic effects, such as decreased inflammation, increased insulin and leptin sensitivity, and decreased hunger and ghrelin levels, especially with twice-daily dosing 1
- The medication is widely available and inexpensive, making it a viable option for patients with prediabetes, polycystic ovary syndrome, and overweight/obesity 1
- Common side effects include gastrointestinal issues like nausea, diarrhea, and abdominal discomfort, which tend to improve over time, and can be minimized by starting with a low dose and taking it with meals
- Metformin is most effective when combined with lifestyle modifications, including diet and exercise, and any off-label use for weight loss should be supervised by a healthcare provider 1
From the Research
Metformin 500mg ER for Weight Loss
- Metformin has been studied for its potential in aiding weight loss, with varying results depending on the population and study design 2, 3, 4, 5, 6.
- In a study comparing orlistat and metformin in patients with polycystic ovarian syndrome (PCOS), metformin produced a significant reduction in total testosterone, but the reduction in weight was less significant compared to orlistat 2.
- A systematic review of metformin treatment in children and adults with obesity found that metformin significantly reduced weight and body mass index (BMI) in adults, but the effects were smaller in children 3.
- Another study found that metformin reduced insulin resistance and its biological variability in overweight women with PCOS, although the reduction in weight was not as significant as with orlistat 4.
- The mechanisms underlying metformin's effects on obesity and weight loss are complex and multifaceted, involving modulation of hypothalamic appetite regulatory centers, alteration in the gut microbiome, and reversal of consequences of aging 5.
- A study examining the effectiveness of metformin for weight loss in non-diabetic individuals with obesity found that metformin was effective in reducing weight, particularly in patients with severe insulin resistance 6.
Key Findings
- Metformin can aid in weight loss, particularly in adults with obesity 3, 6.
- The effects of metformin on weight loss may be smaller in children compared to adults 3.
- Metformin reduces insulin resistance and its biological variability in overweight women with PCOS 4.
- The mechanisms underlying metformin's effects on obesity and weight loss are complex and involve multiple pathways 5.