Metformin Guide: Everything You Need To Know

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- Updated by Dr. Susan Adeosun, MPH, MD

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Metformin is a drug that the FDA verifies for diabetic treatment. It is an antidiabetic drug used to treat type 2 diabetes by controlling high blood sugar levels. It is also one of the most widely prescribed medications in the world. Some common brand names include Glucophage, Glumetza, and Metabet. As a result, being well-informed about Metformin's benefits and other ways it can impact our health is important. 

This guide will discuss everything you need to know about Metformin. Focusing on the Metformin UK landscape, we'll explore its various applications, side effects, and other frequently asked questions. Our goal is to provide you with in-depth knowledge about the medication. And by the end of this guide, you will know enough to use the medication confidently.

How does Metformin work?

Metformin is currently indicated as a first-line drug for type 2 diabetes. Type 2 diabetes is a chronic condition that affects how the body processes blood sugar. The body's main energy source, glucose, is primarily derived from our food. To help us get enough glucose, the pancreas produces the hormone insulin. Insulin aids in transporting blood glucose into the body's cells for use as fuel.

In type 1 diabetes, the body does not produce enough insulin to mop up blood sugar. However, in type 2 diabetes, our cells do not respond to insulin. So, the liver produces more glucose as a negative feedback mechanism, and the amount of glucose in the blood increases even more. Over time, high blood sugar causes issues with the immune, nervous, and circulatory systems. Metformin helps to reduce the risk of developing this complication. 

Medical practitioners prescribe Metformin as a first-line drug to people with type 2 diabetes. It belongs to the class of drugs called Biguanides. Metformin works alone or in combination with other diabetes drugs to improve insulin sensitivity. It also decreases the amount of glucose made by the liver and its absorption by the intestine. 

Metformin is available mainly in tablet forms. It has numerous brands and dosage forms like immediate and extended-release Metformin. The standard initial dosage for Metformin tablet is 500 mg twice a day or 850 mg once daily. Then, an increase of 500 mg weekly or 850 mg every two weeks as tolerated. Some people may take up to 2 g daily.

Metformin’s mechanism of action has been studied intensively. Still, it is not quite fully understood. Current research finds that Metformin acts via both AMP-activated protein kinase (AMPK)-dependent and AMPK-independent mechanisms. Aside from that, more research is still underway.

The Benefits of Metformin

Metformin benefits many medical conditions. One of its primary benefits is its ability to lower blood sugar levels and improve insulin sensitivity. As previously mentioned, this is crucial in managing Type 2 Diabetes. It protects people with diabetes from complications from chronic high blood sugar.

Why is it beneficial to these patients?  A great benefit of Metformin is its low risk of causing low blood sugar or hypoglycemia. Hypoglycemia is a common side effect that occurs while using anti-diabetic medications. This makes Metformin a safer option for many patients. 

Metformin can also play a role in weight management. Usually, diabetes is associated with weight gain. So, Metformin may help with it. However, the FDA has not approved Metformin for this indication. Long-term research found that Metformin patients achieved a 5% weight loss. So, a healthcare provider might prescribe it for patients with type 2 diabetes who are overweight or obese.

Studies have shown that Metformin may also offer cardiovascular benefits for heart diseases. Heart failure is a common complication in patients diagnosed with type 2 diabetes. However, compared to other anti-diabetic drugs, Metformin reduces the risk of heart failure in patients to 20-25%.

In addition to the benefits of Metformin for diabetes management, it is also helpful for women with polycystic ovary syndrome. It can assist in managing insulin resistance, regulating menstrual cycles, and even improving fertility for those affected by Polycystic Ovarian Syndrome (PCOS).

How Metformin Can Help People Who Don’t Have Diabetes?

Metformin benefits have expanded beyond the treatment of diabetes mellitus. According to various research,  Metformin is also useful in treating dementia and cancer and even in preventing diabetes.

The effects of Metformin on dementia, Alzheimer's disease, or any other measure of cognitive impairment were studied compared to any control group that was not taking the medication. There was a significant improvement in the patients that used Metformin. So, it is a good idea to use Metformin as a preventive measure against dementia in high-risk diabetic patients. 

Metformin also finds use in cancer treatment. Numerous studies have seen Metformin benefits in breast, pancreas, liver, colon, ovaries, and prostate tumours. In the case of prevention of diabetes, Metformin therapy prevented the development of diabetes by 58 and 31%, respectively, compared to placebo. Over 15 years, Metformin reduced diabetes by 18% compared to the placebo. 

Metformin pills

Trials to Evaluate Metformin’s Anti-Aging Effects Are in the Works

Researchers are always looking for new ways to use Metformin. Recently, there have been trials to see the influence of Metformin on age and longevity. Initial findings suggest that Metformin could potentially trigger anti-ageing genetic alterations. However, its protective effects on individuals without pre-existing conditions remain debated. 

Additionally, even after six decades of use as an anti-diabetic medication, the precise cellular processes by which Metformin functions are still not well-understood. So, its effects on ageing are still being researched. Overall, its effects in treating diabetes, cardiovascular diseases, and cancer are all instrumental to increasing longevity and lifespan. 

Who Should Take Metformin?

Metformin is a first-line treatment for type 2 diabetes. So, patients with diabetes are the ones who should take Metformin. It is also prescribed for people with prediabetes. Prediabetes is when blood glucose levels are higher than normal but not high enough to be considered diabetes. Metformin may sometimes treat other medical conditions, such as polycystic ovary syndrome (PCOS) in women or gestational diabetes in expectant mothers.

However, Metformin is not suitable for everyone. People with an allergic reaction are not to take Metformin. Metformin is also not used for uncontrolled diabetes and people with liver, kidney, or heart problems. Other people who can’t continue to take Metformin include people who drink high amounts of alcohol. Always talk to your doctor before you start taking Metformin.

Can people without diabetes use metformin?

As previously mentioned, Metformin can be prescribed for other uses. An everyday off-label use of Metformin is weight loss.  In some cases, it is used to prevent cancer or age-related diseases. However, Metformin is a prescription medication and should only be used under the guidance of a healthcare professional. It is not recommended to use Metformin without a medical indication or prescription, as it can cause side effects and interact with other medications.

Are There Any Risks Associated With Metformin?

Metformin has its benefits. Still, there are some risks associated with using Metformin.  A significant risk of taking Metformin is drug-drug interactions. Certain medications, like diuretics or some antibiotics, interact with Metformin. 

They affect how your kidneys function and increase the risk of a rare but severe side effect called lactic acidosis. Drinking alcohol while taking Metformin can also increase this risk. Healthcare providers often advise to stop taking these medications together with Metformin. 

Metformin has also been associated with medication for heart disease, such as beta-blockers. They increase the risk of hypoglycemia, which usually is not present with metformin. Also, if you take vitamin B12 supplements, Metformin has been associated with decreased absorption of vitamin B12, which can lead to a deficiency. The deficiency of vitamin B12 leads to anaemia and could cause death.

Are there side effects of Metformin

Yes, side effects can occur when you start Metformin therapy. Some side effects associated with taking metformin include;

  • Stomach pain

  • Muscle pain

  • Heartburn

  • Bloating

  • Diarrhoea

  • Nausea  

  • Constipation

  • Metallic taste

  • Vitamin B12 deficiency.

Metformin can occasionally result in more severe side effects. For instance, a significant side effect of metformin is a risk of lactic acidosis. This rare but potentially fatal condition can develop when the bloodstream has an excessive lactic acid buildup. People with severe infections, kidney or liver issues, or who consume excessive amounts of alcohol are likelier to experience this. In these cases, it is advised to stop taking Metformin and visit your doctor.


In this guide, we explored UK Metformin benefits. We saw that metformin is used to treat diabetes. The primary function is to lower your blood sugar levels by decreasing liver glucose production and increasing insulin sensitivity.

Additionally, we discussed the potential off-label uses of Metformin, such as weight loss and PCOS. Despite its widespread use for over six decades, the exact cellular processes behind Metformin's actions remain an area of ongoing research. This guide emphasises the importance of consulting a healthcare provider before starting on Metformin.

Also, take your medication and adhere to the proper dose of Metformin because it is important to minimise side effects. If you experience any severe side efetcts, you may need to stop Metformin and talk to your doctor.


Here are some frequently asked questions on Metformin;

Can metformin make you look younger?

No, Metformin does not make you look younger. Some studies suggested that Metformin may have potential anti-ageing benefits. Still, no evidence suggests that it can make you look younger. 

The studies mainly focus on Metformin's effects on cell enzymes and metabolism. They may mimic some of the benefits of calorie restriction linked to longevity. However, further research is needed to fully understand how Metformin may affect the ageing process in humans.

Remember that Metformin is a prescription medication used to manage type 2 diabetes. It should only be taken under the guidance of a healthcare provider. While it may have potential benefits beyond managing blood sugar, it is not a miracle drug that can reverse the effects of ageing or make you look younger. Diet and exercise are other healthy ways to improve your look.


Is metformin FDA approved for anti-ageing?

The FDA approves Metformin to help manage type 2 diabetes. But, studies have shown that it might be helpful in anti-ageing. However, there's still a debate about whether Metformin is the key to living longer. Before using it as a go-to anti-ageing therapy, we need more research to understand its effects on humans fully.

What are the long term effects of using metformin?

Metformin's long-term effects have been thoroughly investigated, and it has been established that when you continue to take your medication as directed, it is safe and effective. Metformin has documented success rates for treating type 2 diabetes, PCOS, and weight management. It is also being researched for other conditions like cancer and anti-ageing.  

However, Metformin can cause side effects, and prolonged use may make some of these more likely. Metformin may have a long-term side effect of decreased vitamin B12 absorption, resulting in anaemia over time. Symptoms of this deficiency include weakness, fatigue, and tingling in the hands and feet.  

In rare cases, Metformin may also cause a serious side effect called lactic acidosis, which is more likely to occur in people with kidney or liver problems, severe infections, or people who drink excessive amounts of alcohol. Research has also linked the use of Metformin to memory loss. But the research is still unclear because other studies say Metformin reduces the risk of dementia.

Does metformin cause hair loss?

There is little evidence that Metformin causes hair loss. There have been some reports of hair loss in people taking Metformin, but it is not a common side effect. In one research, patients with type 2 diabetes who took Metformin and other diabetes medications like sitagliptin experienced hair loss in the eyebrow and eyelashes. 

Still, it's unclear if this was a medication-related side effect or if there were other causes.  Additionally, long-term use of Metformin has been linked to decreased vitamin B12 and folate. This could contribute to hair loss because vitamin B12 deficiency is associated with hair loss.

Does metformin increase muscle growth?

Metformin and muscle growth have been recently linked. A study of burn patients showed that Metformin improves muscle growth. Metformin reduces hyperglycemia and, in turn, boosts muscle protein production. Therefore, treatments that increase glucose tolerance, like Metformin, may significantly reduce muscle catabolism in patients who have suffered critical injuries.