What it is used for
- Helping with insulin resistance and menstrual irregularity in polycystic ovary syndrome (PCOS)
- Supporting ovulation and fertility in some people with PCOS (when prescribed)
- It is also widely used for type 2 diabetes, covered under diabetes care
How it works
It lowers the amount of sugar the liver releases and helps the body respond better to its own insulin. In PCOS this can improve menstrual regularity and other hormone-related symptoms.
How it is taken
Taken as a standard or slow-release tablet, usually with or after food to reduce stomach upset, often starting low and increasing gradually. Take it exactly as your doctor or pharmacist directs.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Nausea
- Diarrhoea
- Stomach cramps
- Loss of appetite
- Metallic taste
- These often ease over time or with the slow-release form
Serious effects — get help
- Severe muscle pain, deep rapid breathing, extreme tiredness, or feeling very unwell (rare lactic acidosis, needs urgent care)
- Signs of very low vitamin B12 over long-term use
- Signs of a serious allergic reaction
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Alcohol in excess
- Some medicines and contrast dyes used for scans (may need to be paused)
- Other diabetes medicines
- Tell your clinician about kidney function and all medicines
Who should take care
- Tell your clinician about any kidney or liver problems, as the dose may need adjusting or the drug avoided
- It may need pausing around certain scans, surgery, or serious illness
- Take with food and increase the dose slowly to limit stomach upset
- Long-term use can lower vitamin B12, which may be monitored