Metformin is usually the first medicine prescribed for type 2 diabetes. It lowers blood sugar mainly by reducing the amount of sugar the liver releases.
- Generic name
- Metformin hydrochloride
- Active ingredient
- Metformin hydrochloride
- Common brands in India
- Glycomet, Glucophage, Obimet, Carbophage
- Available as
- Tablet, Sustained-release (SR/XR) tablet
- Common strengths
- 500 mg, 850 mg, 1000 mg
- How it is sold
- Prescription only — needs a doctor's prescription
No dosage information on this page
The correct dose depends on your age, weight, kidney and liver function, other medicines and medical history. Follow the dose your doctor prescribed, or the instructions on the pack. Never copy a dose from a website or from someone else's prescription.
What Metformin is used for
- Type 2 diabetes — usually the first medicine started
- Prediabetes, in some people at high risk, alongside diet and activity changes
- Polycystic ovary syndrome (PCOS), in some situations
How it works
Metformin reduces the amount of glucose your liver releases into the blood and helps your body's cells respond better to insulin. It does not force the pancreas to produce more insulin, which is why on its own it rarely causes blood sugar to fall dangerously low.
How to take Metformin
- Take it with food or just after a meal. This makes the stomach upset far less likely.
- Swallow extended-release tablets (marked SR or XR) whole. Crushing one releases the whole amount at once.
- Take it at about the same times every day.
- If you miss one, take it with your next meal. Never take two together to catch up.
Precautions
- Your doctor will check your kidney function before starting and periodically afterwards.
- Tell any doctor or radiologist that you take metformin before a CT scan with contrast dye, or before surgery — it usually needs to be paused around these.
- Long-term use can lower vitamin B12 levels, so this is checked from time to time.
- Avoid heavy alcohol use while taking it.
- Do not stop or change the dose on your own, even if your sugar readings look good.
Common side effects
Not everyone gets side effects. Tell your doctor if any of these are troublesome or do not settle.
- Nausea, and a feeling of fullness
- Loose motions or diarrhoea
- A metallic taste in the mouth
- Reduced appetite
- Stomach discomfort or gas
- These are common when starting and usually settle within a few weeks. Taking the tablet after food, or switching to the sustained-release form, often helps.
Important warnings
- Lactic acidosis is a rare but serious complication, more likely in people with significant kidney or liver problems, severe dehydration, or heavy alcohol use.
- Seek urgent medical care if you develop unusual or extreme tiredness, muscle pain or cramps, difficulty breathing, severe vomiting, stomach pain, or feel unusually cold.
- Stop and contact your doctor if you become severely dehydrated from vomiting or diarrhoea.
Frequently Asked Questions
Should metformin be taken before or after food?
With food or just after a meal. Taking it on an empty stomach makes nausea and loose motions considerably more likely.
Does metformin cause low blood sugar?
Rarely on its own, because it does not force the pancreas to release more insulin. The risk rises when it is combined with other diabetes medicines such as sulfonylureas or insulin.
Can I stop metformin once my sugar is normal?
Not without your doctor's advice. Normal readings usually mean the treatment is working, not that the diabetes has gone. Any change should be a decision made with your doctor based on your test results.
Does metformin cause weight loss?
Some people lose a small amount of weight on metformin, often a few kilograms. It is not a weight-loss medicine and should not be taken for that purpose.
What are the side effects of metformin?
The common ones are stomach-related: nausea, a feeling of fullness, loose motions, a metallic taste and reduced appetite. They are usual when starting and normally settle within a few weeks. Taking the tablet after food, or switching to the sustained-release form, often helps considerably.
What this costs, and what is free
Commonly available free at government hospitals and health and wellness centres when prescribed there.
Generic versions are sold at Jan Aushadhi Kendras at substantially lower prices than branded packs of the same medicine.
The same molecule is sold under many brand names at very different prices. Ask your doctor to write the generic name, and compare at a Jan Aushadhi Kendra — the saving on a medicine taken daily is often substantial over a year. You can look up any medicine's official ceiling price on NPPA's Pharma Sahi Daam app.
Source: Pradhan Mantri Bhartiya Janaushadhi Pariyojana (PMBJP), National Pharmaceutical Pricing Authority (NPPA)
Prices and scheme rules change. Confirm current details with the hospital or Kendra before you rely on them.
Looking for Metformin locally?Aswini Medicals is a pharmacy that stocks everyday medicines and can advise on availability.
Visit Aswini Medicals