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As a reproductive endocrinologist, I see cases of polycystic ovary syndrome (PCOS) on a daily basis. One of the most common female endocrine disorders, conservative estimates suggest that PCOS affects approximately five to ten percent of women who are of childbearing age. My ob-gyn colleagues have often asked whether Clomid or metformin is the preferred therapy for PCOS when patients are trying to conceive. The goal of these medications is to induce ovulation so that conception can occur. In my opinion, Clomid is the best choice for first line treatment.

Treatment of PCOS with metformin is relatively new, so medical literature to back up its use and comparative studies have only recently become available. Based on my experience, metformin will almost never take a patient that has menses every two to four months and make the cycles fall in the regular range of every 28-32 days. What metformin will do is take a PCOS patient that ovulates three to four times per year and increase the number to five to seven times per year. However, the metformin cycles usually last much longer than normal, which makes it hard for patients to know in which part of the month they are fertile.

To offer you more information on this topic, I have included abstracts and summaries from medical journals I receive. The February 2009 addition of Fertility and Sterility examined the use of Clomid, metformin, or a combination of the two medications. These sources ultimately recommend starting with Clomid first since it is easier, cheaper, safer, and has fewer side effects; also, the ovulation rates and pregnancy rates are higher with Clomid. Physicians may still consider metformin, but not usually as the first line of treatment. As well, I have found that metformin combined with Clomid or letrozole can help many patients with severe cases of PCOS ovulate without having to add gonadotropins.