Information for the public

About metformin

About metformin

Metformin is a drug commonly used for controlling blood sugar levels in people with diabetes. It helps improve the ability of cells in the body to respond to the normal actions of insulin. Many women with PCOS have what is known as 'insulin resistance' (see 'what is polycystic ovary disease?'). The effects of metformin on the body's response to insulin suggest it might be helpful in managing the symptoms of PCOS, for example in women who don't want to take other treatments or for whom these aren't suitable.

Metformin has a license in the UK for treating type 2 diabetes, particularly for people who are overweight. However it does not have a license for use in PCOS, so use in this way is described as 'off-label'.

It is important to note that metformin is not a contraceptive. Sometimes, women with PCOS who have not got pregnant before taking metformin have got pregnant after starting to take it. In fact, NICE recommends metformin as a treatment option in certain circumstances for women with PCOS who want help to get pregnant. Women with PCOS who do not want to get pregnant but who are thinking about taking metformin to control some of the symptoms of PCOS should discuss their contraceptive needs and options with an appropriate health professional.