Metformin (Glucophage) for polycystic ovary syndrome
How It Works
Metformin lowers blood sugar levels by:
When blood sugar is lower, less insulin is needed, so the body makes less insulin. And when insulin is lower, the body produces a lower level of androgens.
Why It Is Used
Metformin is a diabetes medicine sometimes used for lowering insulin and blood sugar levels in women with polycystic ovary syndrome (PCOS). This helps regulate menstrual cycles, start ovulation, and lower the risk of miscarriage in women with PCOS. Long-term use also lowers diabetes and heart disease risk related to high insulin levels.1
Metformin can be used to treat women who have PCOS to reduce insulin levels and promote normal ovarian function. Metformin is best used in addition to eating a healthy diet, losing weight, and exercising regularly.
How Well It Works
Metformin lowers insulin, androgen, and cholesterol levels. It also improves metabolism in women who are insulin-resistant.
The most common side effects of metformin are:
These side effects occur 20% to 30% of the time. Side effects usually decrease over time. The dosage of metformin is usually increased gradually to prevent these possible side effects.3
Blood levels of vitamin B12 can decrease in women who take this medicine, but the lower level usually does not cause health problems. Doctors do recommend that women on metformin take a daily multiple vitamin supplement.
A rare side effect of taking metformin is a condition called lactic acidosis. This happens when metformin builds up in the blood instead of being removed by the kidneys. If not treated, this acid buildup can lead to coma and death.
Metformin should not be used by women who:
The use of metformin during pregnancy is not well researched. So if you are pregnant or are trying to get pregnant, be sure to talk with your doctor about what is best for you.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
You may need to stop taking metformin temporarily before major surgery or other medical procedures, such as X-rays that use contrast dyes. Talk to your doctor about this before your surgery or procedure.
The effect of metformin may be increased if you also take cimetidine (Tagamet). Before taking metformin, talk with your doctor about any other medicines you are taking.
Metformin is safe to use in teenage girls who have PCOS. Some experts suggest starting long-term metformin therapy when PCOS is first diagnosed, with the goal of lowering the risks of diabetes, infertility, and heart disease. But the safety of long-term treatment is not yet known.4
eMedicineHealth Medical Reference from Healthwise
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