From the Guidelines
Metformin can be used to regulate Polycystic Ovary Syndrome (PCOS), particularly in patients with insulin resistance, prediabetes, or those who are overweight, as it helps reduce insulin resistance, lower blood glucose levels, and androgen production, leading to improved menstrual regularity, reduced hirsutism, and assisted weight management.
Key Points to Consider
- Metformin is typically prescribed at a starting dose of 500 mg once daily, gradually increasing to 1500-2000 mg daily in divided doses to minimize gastrointestinal side effects 1.
- The most recent evidence suggests that metformin is recommended as an adjunct to lifestyle management for treatment of weight, hormonal, and metabolic outcomes in PCOS, with a focus on prevention of weight gain 1.
- Metformin works by reducing insulin resistance, which is common in PCOS patients, and helps lower blood glucose levels and androgen production, leading to improved menstrual regularity, reduced hirsutism, and assisted weight management 1.
- Common side effects of metformin include nausea, diarrhea, and abdominal discomfort, which typically improve over time, and taking metformin with meals can help reduce these effects.
- While not FDA-approved specifically for PCOS, metformin is widely used off-label as part of PCOS management, particularly in patients with insulin resistance, prediabetes, or those who are overweight 1.
Important Considerations
- The association between obesity and PCOS is complex and bidirectional, and weight loss is recommended as part of management in individuals with PCOS with higher body mass index (BMI) 1.
- Lifestyle modifications, including diet and exercise, are challenging to maintain and often insufficient to lead to meaningful weight loss, and pharmacotherapy is recommended as an adjunct to lifestyle approaches to optimize weight loss success and efficacy in obesity 1.
- The need for alternative pharmacotherapies as adjunctive treatments to promote weight loss in PCOS is a key priority, with weight gain a primary concern expressed by those with the condition 1.
From the Research
Metformin and PCOS Regulation
- Metformin, a biguanide, has been proposed as a potential treatment for Polycystic Ovary Syndrome (PCOS) due to its ability to improve insulin sensitivity and reduce insulin resistance 2, 3, 4, 5, 6.
- Studies have shown that metformin can improve menstrual disturbances, reduce androgen production, and increase ovulatory rates in women with PCOS 2, 3, 4, 5.
- However, the effectiveness of metformin in improving hirsutism, a common symptom of PCOS, is uncertain and may depend on the woman's body mass index (BMI) 2.
- Metformin may also increase the incidence of severe gastrointestinal adverse events, but decrease the incidence of severe other adverse events compared to the oral contraceptive pill (OCP) 2.
- The use of metformin in combination with the OCP may be more effective in improving hirsutism and reducing adverse events than metformin alone 2.
Benefits of Metformin in PCOS
- Metformin can improve insulin sensitivity and reduce insulin resistance, which are common features of PCOS 3, 4, 5, 6.
- Metformin may also reduce androgen production rates and improve ovulatory function in women with PCOS 3, 4, 5.
- The Endocrine Society Guidelines recommend the use of metformin during adolescence, particularly when excess body weight is present 5.
- Metformin may also be used as an adjuvant therapy in obese women with PCOS to improve metabolic comorbidities 5.
Limitations and Future Studies
- The evidence for the effectiveness of metformin in PCOS is limited by the quality of the studies, with many having a high risk of bias and imprecision 2.
- Further large, well-designed randomized controlled trials are needed to evaluate the effectiveness of metformin in PCOS, particularly in adolescent women 2.
- Studies should also investigate the optimal dosage and duration of metformin treatment, as well as its potential long-term effects on PCOS symptoms and metabolic outcomes 2, 3, 4, 5, 6.