Metformin is one of the most commonly prescribed medicines worldwide. Metformin belongs to the biguanide family and is an important oral antihyperglycemic drug. Millions of patients rely on this popular drug as their primary first-line treatment for type 2 diabetes to manage their blood sugar levels. Unlike other diabetes medications, patients with type 2 diabetes don't experience hypoglycaemia under normal circumstances. Research shows its benefits go far beyond diabetes management. The drug helps pregnant women control their blood sugar when they develop gestational diabetes. The American Diabetes Association's medical guidelines recognise it as the sole antidiabetic medication suitable for treating prediabetes.

How Does Metformin Work?

The drug controls blood sugar levels through several mechanisms. It reduces glucose production in the liver, limits glucose absorption in the intestines, and helps insulin work better by increasing glucose uptake and use in the body. Metformin maintains insulin secretion without causing hyperinsulinemia and might lower fasting insulin levels. 

Uses of Metformin

Metformin's benefits go beyond treating type 2 diabetes:

• It helps with polycystic ovary syndrome (PCOS) by improving insulin sensitivity and regulating ovarian function

• People with prediabetes can delay or prevent diabetes onset

• Pregnant women can use it to manage gestational diabetes

• The drug helps prevent weight gain from antipsychotic medications like olanzapine and clozapine

How & When to Take Metformin?

• Taking metformin with meals reduces stomach upset and maximises its benefits. 

• Regular tablets need taking 2-3 times daily, while extended-release versions usually work with one daily dose. 

• Taking the medication at consistent times helps maintain steady levels in your body.

What Are the Side Effects of Metformin?

The digestive system experiences the most common side effects:

• Temporary nausea, vomiting and diarrhoea

• Stomach discomfort

• Metallic taste in the mouth

• Loss of appetite

Lactic acidosis is a rare but serious side effect 

B12 deficiency might develop with long-term use.

Can I Take Metformin Daily?

Metformin works best as a long-term treatment. Your doctor might recommend daily use over an extended period if it works well for your condition. Regular use helps maintain proper blood glucose levels consistently. Your dosage should never increase without your doctor's guidance because it could harm you.

Precautions 

You should not take metformin if you have severe kidney disease, metabolic acidosis, or diabetic ketoacidosis. Your doctor needs to review:

• Kidney function (regular monitoring required, especially for those over 65)

• History of heart or liver disease

• Alcohol consumption patterns

• Potential for pregnancy

You must temporarily stop taking metformin before surgery or procedures with iodinated contrast dye. 

Blood sugar monitoring becomes more important during illness, stress, or changes in exercise patterns.

What If I Missed a Dose?

Take the medicine when you remember. Skip the forgotten dose if your next scheduled dose is coming up soon. Double-dosing to make up for a missed tablet is dangerous. An alarm or medication reminder system can help prevent missed doses of medication.

What If I Overdose?

Get medical help right away for a metformin overdose. Watch for these symptoms:

• Stomach pain and severe digestive distress

• Unusual sleepiness or weakness

• Fast or shallow breathing

• Feeling abnormally cold

• Dizziness or lightheadedness

Metformin-associated lactic acidosis has a higher mortality rate. Hemodialysis works best as treatment because metformin has a low molecular weight and minimal protein binding.

Drug Interactions

Metformin interacts with various medications. Here are the main interactions:

• Carbonic anhydrase inhibitors like t

• opiramate, dichlorphenamide 

• Cimetidine 

• Contrast agents 

• Corticosteroids 

• Diuretics

• Insulin

• Oestrogen 

• Other diabetic medicines

• Proton pump inhibitors 

• Ranolazine 

Dosage for Metformin

Doctors start metformin at lower doses. Daily doses max out at 2,000 mg, usually split throughout the day. A typical schedule looks like this:

• Week 1: 500 mg with breakfast

• Week 2: Add a second 500 mg dose with the evening meal

• Week 3: If needed add a third 500 mg dose with lunch

Extended-release tablets work best as a single daily dose with the evening meal. Older, malnourished or weakened patients usually need lower doses.

Metformin vs Sitagliptin 

Understanding the differences between available options helps patients choose the right diabetes medications.

Feature	Metformin	Sitagliptin
Mechanism	Reduces glucose production in the liver, delays intestinal absorption, increases insulin sensitivity	Increases substances that make the pancreas release more insulin, signals the liver to stop producing glucose
Effectiveness	Average HbA1c reduction	Average HbA1c reduction
Common Side Effects	Diarrhoea, upset stomach, headaches	Diarrhoea, vomiting, joint pain
Weight Effect	Average weight loss is more	Average weight loss is comparably less
Drug Class	Non-sulfonylurea	Dipeptidyl peptidase 4 (DPP-4) inhibitors
Half-life	4.5 hours	12.4 hours
Hypoglycaemia Risk	Lower	Higher when combined with other medications

These medications control blood sugar through different pathways and doctors sometimes prescribe them together to improve glucose control. Metformin stands as the first-line therapy because it costs less, works better, and patients report more positive experiences.

FAQs

1. What is metformin used for?

   We used metformin to treat type 2 diabetes when diet and exercise alone don't work. Common uses are:

   • It helps prevent type 2 diabetes in high-risk individuals

   • It manages polycystic ovary syndrome (PCOS) by improving fertility and regulating menstrual cycles

   • It supports gestational diabetes treatment during pregnancy

   • It counteracts weight gain from antipsychotic medications

2. How does metformin work in the body?

   The medication lowers blood sugar through several mechanisms:

   • It decreases glucose production in the liver

   • It reduces intestinal absorption of glucose

   • It improves insulin sensitivity in body tissues

   • It opposes glucagon action

   Metformin doesn't stimulate insulin secretion, which explains why it rarely causes hypoglycaemia when used alone.

3. What is the usual dosage of metformin for adults and children?

   Adults typically follow this dosing pattern:

   • Original dose: 500mg once or twice daily, or 850mg once daily

   • Maximum daily dose: 2,000mg

   Children (10 years or older) should take:

   • 500mg twice daily to start

   • Doses increase gradually based on blood sugar response

4. Can metformin be used to manage type 2 diabetes?

   Metformin stands as the biggest first-line medication to treat type 2 diabetes. The American Diabetes Association recommends it as the first oral medication, especially when you have extra weight. 

5. What are the common side effects of metformin?

   Common side effects are:

   • Nausea and vomiting 

   • Diarrhoea 

   • Stomach upset

   • Metallic taste in the mouth

   • Loss of appetite

6. Is metformin safe for long-term use?

   Research confirms metformin's remarkable safety for extended use. Studies show that no most important safety problems emerged during long-term monitoring. The original gastrointestinal symptoms usually decrease over time. Patients who take metformin should monitor their vitamin B12 levels because extended use might reduce them and cause fatigue and breathlessness. Regular check-ups help prevent this issue.

7. Can metformin interact with other medications?

   Absolutely! Metformin interacts with many drugs. The key interactions include:

   • Cimetidine 

   • Iodinated contrast materials 

   • Ranitidine 

   • Proton pump inhibitors 

8. Is metformin safe during pregnancy or breastfeeding?

   Metformin stays safe throughout pregnancy. Nursing mothers should know that metformin passes into breast milk in tiny amounts without causing side effects in babies. Notwithstanding that, mothers should watch if their baby appears unusually sleepy, irritable, or feeds poorly.

9. What precautions should be taken while using metformin?

   Patients with kidney disease, heart problems, or liver disease need extra caution. They should stop metformin before receiving contrast dyes for imaging studies. Alcohol consumption raises the risk of lactic acidosis.

10. What should I do if I miss a dose of metformin?

    Take it when you remember. Skip the forgotten dose if your next scheduled dose approaches. An alarm helps prevent missed doses.