Metformin

Metformin is a prescription medicine that helps the body respond to insulin and is used in some women's health care plans.

It belongs to a group of medicines that can reduce the amount of glucose released by the liver and support the way tissues use glucose. It is not a hormone and does not replace insulin.

Metformin works mainly on glucose handling rather than directly stimulating the pancreas to release insulin. This means its effect depends on the body's own insulin being present.

Metformin is often discussed in care for polycystic ovary syndrome, particularly when insulin resistance or blood-sugar concerns are part of the clinical picture. A clinician may consider it alongside nutrition, movement, cycle care, or fertility planning.

For condition-specific information, see [Metformin for PCOS](/treatments/medical-gynaecology/metformin-for-pcos/).

The suitable approach depends on the reason metformin is being considered. A care plan may involve lifestyle support, treatment aimed at menstrual or androgen-related symptoms, or another medicine for glucose control. These options address different goals and are not interchangeable without clinical advice.

Take metformin exactly as prescribed, often with food if advised, and follow the instructions for your formulation. Do not double a missed dose unless your prescriber tells you to. Tell your clinician about kidney or liver problems, severe illness, dehydration, or planned procedures, because these may affect whether metformin should be paused or reviewed.

Contact your care team about persistent vomiting, diarrhoea, inability to drink, or troublesome side effects. Never change the dose to influence periods, ovulation, or pregnancy planning without an agreed plan.

Some people use metformin for an extended period when its intended benefit continues. Follow-up may include reviewing symptoms, glucose-related measures, kidney function, and tolerance. A clinician can also consider whether a nutritional issue such as low vitamin B12 needs checking during longer-term treatment.

Metformin is not suitable for everyone. Share a complete medicine list and mention pregnancy, breastfeeding, or a planned contrast scan so your healthcare team can make a safe decision.