Metformin Hydrochloride
Description
Metformin helps lower elevated blood sugar levels. It is important to take this
medication as prescribed by your doctor for the specified duration. Metformin should ideally be taken with food to help prevent nausea and abdominal discomfort. Take it consistently at the same time each day. Do not stop using the medication unless your doctor advises you to do so. Common side effects of Metformin may include diarrhea, nausea, vomiting, gas, weakness, indigestion, abdominal pain, headaches, and decreased appetite. Some individuals might experience hypoglycemia (low blood sugar) when taking this medication in combination with other antidiabetic drugs, consuming alcohol, or missing meals. Be sure to monitor your blood sugar levels while on this medication regularly. Before starting this medication, inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding. Discuss all medications and supplements you are currently taking, as well as any health conditions or diseases you have. Managing diabetes is heavily influenced by your lifestyle; therefore, it is essential to follow the diet and exercise plan recommended by your healthcare provider while using this medication.
Uses
Contraindications
When should one not use Metformin Hydrochloride
- Type 1 diabetes mellitus
- Liver disease
- Kidney disease (severe)
- Heart failure
- Severe respiratory disease
- If you are a heavy drinker of alcohol
- If you are allergic (hypersensitive) to Metformin
- If you have a severe infection such as infections of lung or your kidney. Infections can increase the risk for lactic acidosis (see 'Warnings and precautions')
Side effects
Common side effects of this drug are:
- The most common side effects of Metformin are loss of appetite, nausea, vomiting, stomach ache and mild diarrhea. Do not stop taking medicine if you experience these as these are transient and shall go away after a few weeks...
- Altered taste sensations
- Decreased Vitamin B12 levels
- Skin rashes, redness, itching and hives
- Weight loss is also a known side effect which is desirable in young and middle-aged obese patients
- A rare but severe side effect of Metformin is lactic acidosis (symptoms: nausea, vomiting, generalized muscle weakness and rapid breathing; see warnings section)
- Metformin does not usually cause sudden low blood sugar (hypoglycemia)
- If Metformin is prescribed with other anti-diabetic medications, there may be an occurrence of low blood sugar level
- Metformin can cause abnormal liver function tests and hepatitis. If you notice yellowing of the eyes or skin, contact your doctor immediately
Precautions and Warnings
Pregnancy
Breast Feeding
Driving
Alcohol
Other General Warnings
- You experience vomiting, stomach ache, muscle cramps, difficulty in breathing, reduced body temperature and heartbeat
- Stop the medication of Metformin for a short time if you have a condition that may be associated with dehydration (significant loss of body fluids) such as severe vomiting, diarrhea
- Metformin can cause a critical condition called lactic acidosis
- The risk factors are uncontrolled diabetes, serious infections, prolonged fasting or alcohol intake, dehydration, liver problems and any severe heart conditions
Mode of Action
How Does It Work?
- Your pancreas produces a hormone called insulin. Insulin drives glucose (sugar) from the blood to enter inside the cell. Then this glucose is utilized as energy by the cell
- If you have diabetes mellitus, your pancreas either does not make enough insulin or your body is unable to use the insulin it produces properly (insulin resistance). As a result, glucose is not able to enter into the cells and this leads to a high level of glucose in your blood...
- Metformin works by decreasing the amount of glucose absorbed from the intestine, lowering the amount of sugar created by the liver and facilitating entry of sugar into the cells
Interactions
Interactions with other medicines
- Phenytoin
- Birth control pills or hormone replacement therapy
- Diet pills or medicines to treat asthma, colds, or allergies
- Increase urine production (a diuretic)
- Heart or blood pressure medications
- Niacin
- Phenothiazines
- Steroids (Prednisone, Methylprednisolone, Dexamethasone and others)
- Thyroid medicine
- Medicines like Furosemide and Cimetidine can increase the side effects of Metformin
- If you need to have an injection of iodine-containing contrast medium into your bloodstream, for an X-ray or scan, your doctor will ask you to stop taking Metformin before or at the time of injection
- If you are on medicines that are used to treat pain and inflammation (NSAID and COX-2 inhibitors such as Ibuprofen and Celecoxib) for the long term, these can damage your kidneys. Use of such medicines in diabetes should be avoided...
Interactions with food items
Dietary Restrictions
Dosage
Overdose
Missed a Dose
Content Details

Dr. Mansi Savla
B. Pharm, PharmD

Dr. Ritu Budania
MBBS, MD (Pharmacology)
Frequently Asked Questions (FAQs)
Q: What should I tell my healthcare provider before I start treatment with Metformin?
Q: What food items should I include in my diet?
- A diet should be high in fibre, low in fat, and include adequate protein, carbohydrates, vitamins, and minerals. It should consist of boiled, steamed, or baked food. Use edible oils such as groundnut oil and olive oil in moderation. Maintain regular meal times and try to have 2-3 healthy snacks between meals, like soups and salads....
Q: Can I stop taking Metformin if my blood sugar level comes under control?
Q: What is the best time to take Metformin?
- You can take Metformin at any time of the day, as advised by the doctor. But it's best to take this medicine with a meal to reduce the side effects.
References
- Diabetes.co.uk.metformin. [Accessed 16th September 2025] (online)
- Ema.metformin. [Accessed 16th September 2025] (online)
- Lactmed. metformin. [Accessed 16th September 2025] (online) Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Metformin. [Updated 2018 Oct 31]
- Care.daibetes.metformin. [Accessed 16th September 2025] (online)