Metformin: Price, Dosage & Where to Buy

Metformin is a biguanide medicine used to improve blood sugar control in adults and children aged 10 years and older with type 2 diabetes mellitus. It is taken alongside diet and exercise.

Metformin requires a prescription in the United Kingdom. Generic metformin has been available since January 2002.

Metformin is used as an adjunct to diet and exercise to improve glycaemic control in adults and children aged 10 years and older with type 2 diabetes mellitus. It helps manage blood sugar levels in people whose diabetes is not adequately controlled through lifestyle measures alone.

Metformin does not treat type 1 diabetes or diabetic ketoacidosis. The medicine works as part of a broader diabetes management plan that includes healthy eating and regular physical activity.

The label lists oral solution at 500 mg per 5 mL, tablets at 500 mg, 625 mg, 750 mg, 850 mg, and 1000 mg, and extended-release tablets at 500 mg, 750 mg, and 1000 mg. The usual starting dose is 500 mg once daily with the evening meal for extended-release tablets. The label lists dose increases in increments of 500 mg weekly, based on blood sugar control and tolerability, up to a maximum of 2,000 mg once daily with the evening meal.

If blood sugar control is not achieved at 2,000 mg once daily, the label lists a trial of 1,000 mg twice daily as an option. Patients should swallow extended-release tablets whole and never crush, cut, or chew them. If a dose is missed, the label advises not taking two doses the same day and resuming the usual dose with the next scheduled dose.

Metformin belongs to a class of medicines called biguanides. It lowers blood sugar primarily by reducing the amount of glucose the liver releases into the bloodstream. Metformin also improves the way the body responds to insulin, helping cells take up glucose more effectively.

Unlike some other diabetes medicines, metformin does not cause the pancreas to release more insulin. This means it rarely causes blood sugar to drop too low when used on its own, though hypoglycaemia can occur when metformin is combined with insulin or certain other diabetes medicines.

Limited data with metformin in pregnant women are not sufficient to determine a drug-associated risk for major birth defects or miscarriage. Published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk. There are risks to the mother and foetus associated with poorly controlled diabetes in pregnancy.

Animal studies in rats and rabbits at doses up to 2- and 5-times a clinical dose showed no adverse developmental effects. The developmental and health benefits of treatment should be considered along with any potential risks. Women who are pregnant or planning pregnancy should discuss metformin use with their doctor or pharmacist.

If a dose of metformin extended-release tablets is missed, the label advises not taking two doses the same day. Instead, resume the usual dose with the next scheduled dose. Do not double up to make up for a forgotten dose.

Missing a single dose is unlikely to cause immediate problems with blood sugar control, but consistent use as prescribed helps maintain steady glucose levels. If doses are missed frequently, speak to a doctor or pharmacist for advice on managing the diabetes treatment plan.

The label lists storage at 20° to 25°C (68° to 77°F), with excursions permitted between 15° to 30°C (59° to 86°F), which corresponds to controlled room temperature. The label specifies dispensing in a light-resistant container to maintain quality. Keep the medicine in its original packaging until it is time to use it, away from moisture and direct light.