What is Metformin?

Metformin Diabetes

Metformin is a prescription medicine used to treat type 2 diabetes and gestational diabetes. It can also help prevent type 2 diabetes if you're at high risk. Type 2 diabetes occurs when the body doesn't produce enough insulin or the insulin doesn't work properly, causing high blood sugar levels (NHS, 2022). Metformin is usually prescribed when diet and exercise alone aren't enough to control blood sugar levels.

How does Metformin work?

Metformin Tablets

Metformin tablets helps lower blood sugar by improving how your body handles insulin - telling your liver to make less glucose, lowering your insulin resistance to help your muscles use insulin more efficiently to allow glucose to get into them instead of staying in your blood and helping your intestines to absorb less glucose from the food that you eat (WebMD, 2023).

Metformin is also sometimes used to manage polycystic ovary syndrome (PCOS) by lowering insulin and blood sugar levels, which can improve ovulation and encourage regular periods, even if you don't have diabetes. However, it is not officially licensed for PCOS; you should always consult your doctor prior to starting any medication to ensure that it is safe and suitable for your medical needs.

How do I know if Metformin is working for me?

Signs that Metformin is working include:

• Lower blood sugar levels
• Lower haemoglobin A1c levels (a long-term measure of blood sugar)
• Some weight loss or no weight gain

These signs may not be the same for everyone. If you're unsure if Metformin is working, talk to your doctor.

Video: A Guide to Metformin

UK Meds have created a video guide to explain what Metformin is. Watch it below:

What are benefits of taking Metformin?

Metformin can be beneficial in helping restore the body’s proper response to the insulin that is naturally produced.  It decreases the amount of sugar that your liver makes and that your stomach and intestines absorb.

Metformin lowers your risk of the complications of diabetes such as kidney damage, nerve problems, blindness, loss of limbs, and sexual problems and can also lower your risk of a heart attack or a stroke.

Each type-2 diabetes patient has a unique individual experience when taking Metformin tablets as a treatment prescribed by their doctor.

Metformin Reviews

There are a large selection of Metformin reviews describing what people think about their experiences with the medication available above from other UK Meds customers and also at Drugs.com and Web MD.

It is important to note that people may have different experiences when they use Metformin. If someone states that their medication did not work as they had hoped, it does not mean that it will not work for you. If you believe that Metformin tablets are the right medication for you then the best thing to do is to consult your doctor or healthcare professional, and judge the medication based on your own experiences if they recommend it as a treatment. The importance of user reviews should not be understated. Reading reviews and patient experiences can provide you with important advice and information that you may not have known, and can inform you on whether or not to start using Metformin. Before starting a medication you should always consult with your healthcare provider first to ensure that it is safe and suitable for your individual needs.

For more information on the prescription medication patients should refer to the Metformin patient information leaflet.

How do I use Metformin?

Before you start taking Metformin, you should carefully read the patient information leaflet that comes with the package of the product.  Do the same thing each time you get a refill of the medication.

Take Metformin by mouth as directed by your doctor, usually one to three times a day with meals. Drink plenty of fluids while you are taking this medication unless your doctor will direct you not to.

The dosage of Metformin is based on your medical condition, your response to the treatment, and other medications that you are currently taking.

Your doctor may start you with the lowest dose of Metformin in order to reduce your risk of side effects, then gradually increase the dose as you get used to the medication. Always carefully follow the instructions of your doctor.

If you are already taking another diabetes medication, follow the directions of your doctor on how to carefully stop or continue the old drug and starting Metformin.

Check your blood sugar regularly as directed by your doctor. Share the results with your doctor especially when the measurements are too high or too low. Your doctor may have to adjust your dose or change your treatment.

How long do I take Metformin for?

You usually take Metformin for life to treat diabetes. However, you might need to switch to another medicine if you get other conditions like kidney failure or if Metformin causes side effects. Don't stop taking Metformin without talking to your doctor, as this can make your blood sugar levels spike and worsen your diabetes.

What is the recommended dosage for Metformin?

Metformin 500mg / Metformin 850mg

• Starting Dose: Usually 500 mg or 850 mg, 2 or 3 times daily, during or after meals.
• Adjusting Dose: After 10 to 15 days, your dose may be adjusted based on blood glucose levels. Increasing the dose slowly can help reduce stomach side effects.
• Maximum Dose: The highest recommended dose is 3 g daily, split into 3 doses.
• Switching from Another Medicine: If you're switching from another diabetes medicine, stop taking the old one and start metformin at the usual starting dose.

Your doctor may adjust your dose depending on your response to the treatment.

Could my Metformin dosage change over time?

Your doctor will check your blood sugar levels regularly and may adjust your dose if needed. When you first start taking standard metformin tablets, your dose will be increased slowly to reduce side effects:

• Week 1: One 500mg dose with or after breakfast.
• Week 2: One 500mg dose with or after breakfast and your evening meal.
• Week 3: One 500mg dose with or after breakfast, lunch, and your evening meal.

Always consult with your doctor for appropriate advice on dosing your medication to ensure that it is safe for you.

What should I do if I miss a dose of Metformin?

If you miss a scheduled dose of Metformin, skip the missed dose and take the next one as usual. Do not take a double dose.

Can you overdose on Metformin?

Yes, it is possible to overdose on Metformin. Taking too much of the medication can cause lactic acidosis. Symptoms include:

• Extreme tiredness
• Raised heart rate
• Breathing difficulties
• Muscle cramps
• Fever
• Stomach ache
• Being sick
• Feeling generally unwell

If you experience any of these symptoms after taking too much of the medication, stop taking it and call 111 or go to A&E immediately. Strictly follow the dosage instructions that your doctor recommends for you when taking it.

What are common side effects of Metformin?

Like all medicines, metformin can cause side effects, but not everyone gets them. Common side effects occur in more than 1 in 100 people (NHS, 2022).

Common Side Effects of Metformin

Talk to your doctor if these tips don't help and the side effects bother you or last more than a few days.

How long do Metformin side effects last?

Metformin side effects vary by person. Most mild side effects should go away on their own as your body gets used to the medication.

Can Metformin have any serious side effects?

Serious side effects are rare, happening in less than 1 in 10,000 people.

Call your doctor or 111 immediately if:

• You feel very unwell with severe tiredness, fast or shallow breathing, feeling cold, or a slow heartbeat.
• The whites of your eyes or your skin turn yellow (this may be less obvious on brown or black skin), which can be a sign of liver problems.
• You start to experience a serious allergic reaction (anaphylaxis)

Low Blood Sugar (Hypoglycaemia)

Metformin alone usually doesn't cause low blood sugar (hypoglycaemia or "hypos"), but it can happen if you take it with other diabetes medicines like insulin or gliclazide. If you experience these symptoms, do not drive or operate any machinery and seek medical help immediately.

Early warning signs of low blood sugar include:

• Feeling hungry
• Trembling or shaking
• Sweating
• Confusion
• Difficulty concentrating

Low blood sugar can also occur while you sleep, making you feel sweaty, tired, and confused when you wake up.

Low blood sugar may happen if you:

• Take too much of some diabetes medicines
• Skip meals or don't eat at regular times
• Fast
• Don't eat a healthy diet or get enough nutrients
• Change what you eat
• Exercise too much without eating enough carbohydrates
• Drink alcohol, especially after skipping a meal
• Take some other medicines or herbal remedies
• Have a hormone disorder, such as an underactive thyroid (hypothyroidism)
• Have kidney or liver problems

To prevent hypoglycaemia:

• Have regular meals, including breakfast. Try not to miss or delay a meal.
• Eat carbohydrates like bread, pasta, or cereals before, during, or after exercise if you're planning to exercise more than usual.
• Always carry a fast-acting carbohydrate, like sugar cubes, fruit juice, or sweets, in case your blood sugar gets low. Artificial sweeteners won't help.
• You may also need to eat a starchy carbohydrate, like a sandwich or a biscuit, to maintain your blood sugar for longer.

Call your doctor or 111 if taking sugar doesn't help, or the hypo symptoms come back.

Make sure your friends and family know about your diabetes and the symptoms of low blood sugar so they can recognise a hypo if it happens.

Who is Metformin not suitable for?

• Do not use metformin if you have severe kidney disease, metabolic acidosis, or diabetic ketoacidosis (contact your doctor for treatment).
• Avoid metformin if you are allergic to it.

Before Taking Metformin

• Inform your doctor if you have had kidney disease, heart disease, liver disease, high ketone levels, or if you use insulin or other diabetes medications.
• If you need surgery or an x-ray with injected dye, you may need to temporarily stop taking metformin. Make sure your healthcare providers know you are using it.

Risks and Precautions

• Metformin can cause lactic acidosis, a rare but dangerous build-up of lactic acid in the blood. Symptoms include unusual muscle pain, trouble breathing, stomach pain, dizziness, feeling cold, or extreme weakness. Seek medical help immediately if these occur.
• Lactic acidosis risk may be higher if you have other medical conditions, severe infections, chronic alcoholism, or are 65 or older.
• Metformin may stimulate ovulation in premenopausal women, increasing the risk of unintended pregnancy. Discuss this with your doctor.
• Do not breastfeed while using metformin.
• Metformin should not be given to children under 10 years old, and some forms are not approved for those under 18.

Interactions

Metformin might not be right for everyone. Certain conditions or medications can interact with it, making it less effective or unsafe. Always tell your doctor or pharmacist about any other medicines you are taking, have recently taken, or plan to take before starting Metformin. Avoid drinking too much alcohol while on Metformin.

Medicines that may interact with Metformin:

• High blood pressure medications
• Beta-2 agonists (like salbutamol or terbutaline for asthma)
• NSAIDs (like ibuprofen and celecoxib)
• Diuretics (medicines that increase urine production)
• Corticosteroids (for skin inflammation or asthma)
• Medicines that affect Metformin levels in your blood (such as verapamil, rifampicin, cimetidine, dolutegravir, ranolazine, trimethoprim, vandetanib, isavuconazole, crizotinib, olaparib)
• Other diabetes medication

Is Metformin safe for pregnancy?

Yes, metformin is safe to take during pregnancy, either on its own or with insulin.

• Follow your doctor's instructions if you are pregnant or become pregnant while taking metformin. Controlling diabetes during pregnancy is crucial to avoid complications for both mother and baby.

Can you take Metformin while breastfeeding?

Yes, if your doctor or midwife says your baby is healthy, you can take metformin while breastfeeding (NHS, 2022). Metformin passes into breast milk in tiny amounts and hasn't been linked with side effects in breastfed babies.

However, contact your health visitor, midwife, pharmacist, or doctor if your baby:

• Is unusually restless or irritable
• Seems unusually sleepy or drowsy
• Looks paler or is sweatier than usual
• Is not feeding as well as usual
• Seems hungrier than usual
• Is peeing more
• Causes you any other concerns

Always consult your doctor if you have any concerns or questions about taking metformin.

Can metformin cause diarrhoea?

Yes, diarrhoea is one of the most common side effects of metformin. Most common side effects of using metformin are related to the stomach including abdominal pain, nausea, indigestion and a loss of appetite (Foss & Clement (2012)).

Does Metformin make you tired?

Metformin can cause vitamin B12 deficiency if taken for a long time, which can make you feel very tired, breathless, and faint. Your doctor may check your vitamin B12 levels and, if they're too low, recommend vitamin B12 supplements.

Does Metformin cause weight gain?

No, Metformin does not cause weight gain.

Does Metformin help you lose weight?

Metformin isn't a magic weight loss pill and is primarily a treatment for diabetes in the UK. However, it might help you lose a modest amount of weight and prevent weight gain (WebMD, 2023).

You probably won't lose as much weight with metformin as with other diabetes drugs like semaglutide (Ozempic, Wegovy) or tirzepatide (Mounjaro). The MHRA has approved Wegovy and Mounjaro for treating weight loss specifically.

Metformin's weight-loss effects aren't consistent enough for it to be considered a weight-loss drug, and it can't replace a healthy diet and regular exercise.

Speak to your doctor for advice on how different medications can help you, to ensure that they are safe and suitable for your individual medical needs.

Does Metformin cause Dementia?

There is no evidence that Metformin causes dementia. Some studies suggest that taking Metformin might even reduce the risk of developing dementia later in life (Chin-Hsiao, T., 2019; Ji et al, 2022; Huang et al, 2023). However, you should only take Metformin for the condition it has been prescribed for.

Does Metformin cause high blood pressure?

No, Metformin will not increase blood pressure. In fact, it can help lower it by improving insulin resistance and reducing blood sugar production in the liver. Better blood sugar control helps prevent damage to blood vessels that leads to high blood pressure. A study even suggests that Metformin has no significant impact on increasing blood pressure in hypertension (Snorgaard et al, 1997). If you have high blood pressure, there are treatments available to help manage it.

How do I buy Metformin online?

You can safely buy Metformin online at UK Meds. You will first need to have an online consultation with a GMC registered doctor, if clinically approved, you can continue with your order. The online consultation will ensure that Metformin is the right medication for your medical condition.

Do I need a prescription to buy Metformin?

Yes, you need a prescription to buy Metformin. You can obtain this from your doctor and provide it to us, or alternatively, you can complete our quick and convenient online clinical consultation and the decision to prescribe will be made by a GMC registered doctor.

Can I get Metformin on the NHS?

Yes, Metformin is available on the NHS. People with diabetes can get free prescriptions for all their medications, including Metformin. Your doctor can help arrange a medical exemption certificate for your prescriptions if you have diabetes.

Are there any alternative diabetes treatments to Metformin?

Alternatives diabetes medications to Metformin include the prescription medicines Ozempic (semaglutide), Mounjaro (tirzepatide), Glucophage SR, Gliclazide and Jardiance amongst others. Unlike Metformin, Ozempic and Mounjaro are injectable. Your doctor can help you to determine which diabetes medication is the best option for your individual medical requirements.

• Metformin - NHS
• Metformin and Reduced Vitamin B12 Levels - GOV.UK
• Metformin - Drugs.com
• Metformin for Diabetes - Patient.info
• Metformin Oral - WebMD
• Metformin - EMC
• Metformin Containing Medicines - EMA
• Metformin Hydrochloride - BNF
• Metformin - ScienceDirect
• Metformin Oral Route - Mayo Clinic

More Information

• Difference between type 1 and type 2 diabetes
• What does Metformin do?