About metformin hcl
Biguanide blood-sugar-lowering medicine
Used for
- Type 2 diabetes, alongside diet and exercise.
- Sometimes used for polycystic ovary syndrome, off-label.
Usual adult dose
Usually 500–2,000 mg once daily with food; increase gradually. Maximum commonly 2,000 mg daily.
Usual dose in children
For type 2 diabetes from age 10: usually 500 mg once daily with food; increase gradually, maximum 2,000 mg daily.
Common side effects
- Diarrhoea, nausea, vomiting, or stomach discomfort.
- Reduced vitamin B12 levels with long-term use.
- Rarely, lactic acidosis, a serious buildup of lactic acid.
Important warnings
- Avoid with severe kidney impairment; kidney function needs monitoring.
- Temporarily stop around some contrast scans or major surgery, as directed by clinicians.
- Excessive alcohol increases the risk of lactic acidosis.
- Seek urgent care for unusual weakness, breathing difficulty, or severe stomach symptoms.
Pregnancy
Metformin may be used in pregnancy when clinically appropriate; treatment should be reviewed by a clinician.
Breastfeeding
Small amounts enter breast milk; it is generally considered compatible with breastfeeding in healthy, full-term infants.
Interactions
- Iodinated contrast agents may require temporary interruption.
- Some medicines, including cimetidine, can affect metformin levels.
- Alcohol increases the risk of lactic acidosis.
- Other diabetes medicines can increase the risk of low blood sugar.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.