What is the role of Metformin (Metformin hydrochloride) in the treatment of Polycystic Ovary Syndrome (PCOS)?

From the Guidelines

Metformin is a recommended treatment for polycystic ovary syndrome (PCOS), particularly for improving menstrual cyclicity and hyperandrogenism, as evidenced by the most recent guidelines 1.

Key Points

• Metformin works by reducing insulin resistance, a common issue in PCOS, which contributes to many of its symptoms.
• By improving insulin sensitivity, metformin helps lower androgen levels, regulate menstrual cycles, improve ovulation, and may assist with weight management.
• The typical starting dose of metformin is 500 mg once daily with a meal, gradually increasing to 1500-2000 mg daily divided into 2-3 doses to minimize gastrointestinal side effects.
• Treatment duration is usually long-term, as PCOS is a chronic condition requiring ongoing management.
• Common side effects of metformin include nausea, diarrhea, and abdominal discomfort, which typically improve over time.
• Taking metformin with food and gradually increasing the dose helps minimize these effects.

Benefits and Considerations

• Metformin can also reduce the risk of developing type 2 diabetes in women with PCOS.
• It is essential to use metformin as part of a comprehensive treatment plan that includes lifestyle modifications such as regular exercise and a balanced diet.
• The American College of Obstetricians and Gynecologists (ACOG) notes that insulin-sensitizing agents like metformin can improve metabolic outcomes in women with PCOS 1.
• Recent guidelines suggest evaluating for PCOS in female adolescents with type 2 diabetes and considering metformin for improving menstrual cyclicity and hyperandrogenism 1.

From the Research

Metformin and PCOS

• Metformin is an insulin-sensitizing agent that has been used to treat polycystic ovary syndrome (PCOS) by improving insulin resistance and reducing androgen levels 2.
• Studies have shown that metformin can decrease fasting and stimulated plasma insulin levels, promote body weight loss, and improve ovarian function in women with PCOS 2, 3.
• The dose of metformin required to achieve significant results in terms of clinical, metabolic, and hormonal responses may need to be adjusted based on the patient's body mass index (BMI) 3.

Effects of Metformin on PCOS Symptoms

• Metformin has been shown to improve menstrual regularity, reduce hirsutism and acne, and increase the likelihood of ovulation in women with PCOS 2, 4.
• Metformin may also have a beneficial effect on lipid profiles, reducing the risk of cardiovascular disease in women with PCOS 5.
• The anti-Mullerian hormone (AMH) has been proposed as a biomarker of the effectiveness of metformin therapy in women with PCOS, with reductions in AMH levels indicating improved ovarian function and reduced polycystic morphology 6.

Clinical Use of Metformin in PCOS

• The Endocrine Society Guidelines recommend the use of metformin in adolescents with PCOS, particularly when excess body weight is present 4.
• Metformin may be used as a first-line treatment for metabolic comorbidities in women with PCOS, and may also be used to improve ovulatory function in women who have failed to respond to other treatments 4, 5.
• Further research is needed to clarify the role of metformin in the treatment of PCOS, including larger randomized controlled trials and meta-analyses 5.