Metformin dose in polycystic ovary syndrome (PCOS)

A study examined different dose regimes in polycystic ovary syndrome (PCOS):

• A :500 mg twice a day (1000 mg);
• B :500 mg three times a day (1500 mg);
• C :850 mg twice a day (1700 mg).

The study study comprehensively analysed the dose-response relationship of metformin on clinical, hormonal and metabolic aspects of PCOS.

The authors concluded that "... results from our study seem to indicate that the effects of metformin treatment in PCOS are independent of the administered dose. Different anthropometrical and metabolic characteristics do not give grounds for an adjustment of the dose of the drug. Hence, since metformin efficacy in PCOS seems not to be dose related, while side effects are, low dosages should be preferred in the clinical practice."

Titration of metformin

An NHS source suggests a titration schedules for metformin (1) with women with side effects having a slower titration to a target dose of 1g twice daily of metformin.

Slow route (in women with side effects) as:

• Week 1 - 250mg once a day
• Week 2 - 250mg twice a day
• Week 3 - 250mg three times a day
• Week 4 - 500mg twice a day
• Week 5 - 500mg three times a day
• Week 6 - 1g twice a day

Reference:

• Fulghesu AM et al. Is there a dose-response relationship of metformin treatment in patients with polycystic ovary syndrome? Hum Reprod. 2012 Oct;27(10):3057-66.
• Royal Berkshire NHS Foundation Trust (Accessed 24/6/15). Use of metformin in PCOS.