Round white Metformin pills

Have you been prescribed metformin? Learn more about why metformin is prescribed, the benefits of metformin, possible side effects, and more. 

If you have been newly diagnosed with type 2 diabetes, you’ve likely discussed treatment options with your doctor and are doing lots of research into the condition. You are also probably finding that there is a large community of health care providers to support you from early testing, diagnosis, and diabetes management. 

If you are doing research on your own, you have come to the right place. We here at Diathrive get it, and we’re here to provide some helpful information through articles like this one to help you understand diabetes and the treatment options available to you. 

Let’s start with some basics, then we’ll talk about what Metformin is and what it might mean to your new daily routine. 

Diabetes Basics

When you eat, your body starts working to turn your food into fuel. Your food is digested to become the energy your body needs. Glucose is the main energy source for your body, but it needs help getting into your cells. 

Diabetes happens when your body cannot efficiently convert glucose into energy, causing a buildup of sugar (glucose) in your blood. Insulin is a hormone made in the pancreas that allows your cells to use glucose. But, for people with diabetes, the pancreas either doesn’t make enough insulin or does not use it efficiently, resulting in high blood sugar.

Type 1 and type 2 diabetes have similar symptoms and the same complications over time, but they are different conditions with different treatment options. Let’s quickly review some of the differences between type 1 and type 2 diabetes, the two most common types. 

Type 1 diabetes is less common than type 2 diabetes (about 10% of all diagnosed cases of diabetes). Type 1 diabetes occurs when an autoimmune condition causes your body’s immune system to attack and destroy the cells in your pancreas that produce insulin. Because the pancreas no longer makes any insulin, people living with type 1 diabetes must regulate and inject insulin every day so that their body can use the glucose in their blood to fuel their cells and reduce glucose buildup (high blood sugar). 

Type 2 diabetes is the most common form of diabetes. If you are living with type 2 diabetes, your body does not produce enough insulin or does not use it efficiently. Treatment of type 2 diabetes is different from person to person. Lifestyle changes like diet and exercise help people living with type 2 diabetes manage their condition, and in some cases can be used to manage type 2 diabetes without the need for medication. When medication is needed, some people need insulin, and some need different medications. 

This brings us to the discussion of metformin, which is the most common medication prescribed for people living with type 2 diabetes. Metformin works by reducing sugar production in the liver and increasing insulin sensitivity, which helps lower blood sugar. 

Medications for Type 2 Diabetes

Your health care provider has many medication options to treat type 2 diabetes. Some help your pancreas produce more insulin. Others, like metformin, work by preventing the production and release of glucose from your liver, while increasing your cell’s sensitivity to insulin. In fact, metformin is the most commonly prescribed medication for type 2 diabetes. 

Some of the benefits of metformin include low cost, few side effects, and effectiveness especially for people living with type 2 diabetes who are overweight and are insulin resistant. Metformin can also help with weight loss and reducing your cholesterol level.  

Metformin is known by many brand names: Glucophage, Fortamet, Glumetza, Glucient, Diagemet, Bolamyn, Metabet, and Riomet. 

There are two types of metformin: 

  • Immediate-release, sometimes called IR. Metformin IR is usually taken two to three times a day with meals.  

  • Extended-release, sometimes called ER or XR. Metformin ER (XR) is taken only once a day, usually at night with dinner.

The dose and type of metformin you take will be determined by your healthcare provider, and depends on several factors including your medical condition, how your body responds to treatment, and other types of medication you are taking. 

Side Effects of Metformin

Although metformin is widely considered to have few side effects, it does cause unwanted effects in some people. 

The most common side effects are diarrhea, nausea, upset stomach, heartburn, and sometimes vomiting. Other side effects include weight loss, a reduction in vitamin B12 levels (because metformin can block B12 absorption), a metallic taste in your mouth, gas, and bloating. 

More serious side effects can include breathing problems, feeling very tired, and muscle pain. 

These side effects can often be avoided if the medication is taken with food, and tend to lessen over time. 

Health care providers also often start with smaller doses of metformin at first, increasing the dose over time. This can help reduce side effects, but it also takes longer to see results because the dosage starts out small. 

Metformin ER can help reduce stomach pains compared to metformin IR, as well as help maintain better control of blood glucose levels. Unfortunately, Metformin ER doesn’t reduce other side effects. 

Your healthcare provider will know what type of metformin (IR or ER) is best for you, but make sure you let them know if you are having side effects so you can possibly adjust as needed.

Lactic acidosis can also occur when taking metformin and happens when lactic acid builds up in your blood. This side effect is often associated with the buildup of Metformin in your blood associated with kidney problems. This is a serious side effect since acute heart failure or serious liver problems can happen when lactic acid builds up. 

There is a condition called a “faux low” that can occur when using metformin. In this case, you might feel like your blood glucose is low. You may feel shaky, irritable, tired, lightheaded, nauseous, or extremely hungry. 

If you experience these symptoms, check your blood sugar to make sure you aren’t actually experiencing low blood sugar (hypoglycemia). If your blood sugar is normal, keep taking metformin as your health care provider has directed. If you are experiencing hypoglycemia follow your diabetes treatment plan to bring your blood glucose levels back up, and contact your healthcare provider. 

Metformin can also interact with other medications, so make sure your health care provider knows about all the medications you are taking, including blood pressure medication, supplements and vitamins.

How to Reduce Side Effects

The list of side effects may seem long and a bit scary, but most people who take Metformin have mild side effects that go away over time. Always discuss side effects with your healthcare provider, including if you notice that side effects go away. 

Some strategies for reducing side effects include: 

  • Take metformin with food

  • Drink lots of fluids

  • Use a heating pad for stomach pain

  • Try small, frequent meals throughout the day

  • Chew sugar free gum if you have a metallic taste in your mouth  

Who Shouldn’t Take Metformin?

Not everyone is a good candidate for metformin. It’s important to make sure your health care provider knows if you have a history of heart problems (heart attack or heart failure), kidney or liver problems, low blood sugar (known as hypoglycemia), or diabetic ketoacidosis. Hypoglycemia is often associated with the use of insulin or medications that increase insulin production (sulfonylureas), or excessive alcohol consumption. 

It is also not recommended for people over 80 years old because your kidney function tends to decrease as you get older, whether you have diabetes or not. Metformin is also not typically prescribed for children under 10 years old. 

How Metformin Works

Recall the discussion above about type 1 and type 2 diabetes? All people living with type 1 diabetes need to take insulin, but not all people living with type 2 diabetes do. 

Daily injections of insulin increase the amount of insulin in your body to allow your body to convert glucose to energy. People living with type 1 diabetes have to replace the insulin their body no longer makes. 

Metformin is different because it doesn’t increase insulin levels. Metformin actually decreases the amount of sugar your body produces. The effect is the same -- reducing the amount of glucose in your blood -- but the way it works is different. 

Metformin is primarily used for people who are living with type 2 diabetes, but some doctors prescribe metformin for people living with type 1 diabetes who are also overweight, or have become resistant to the insulin they take. 

It’s important to know that metformin doesn’t work immediately, meaning it doesn’t have overnight results. Metformin works over time to bring down your blood sugar gradually and is combined with healthy eating and exercise.  


Metformin is the most commonly prescribed medication for type 2 diabetes. It works to reduce blood sugar by reducing the production of glucose in your liver and increasing your body’s sensitivity to insulin. 

Metformin has few side effects when compared to other medications, and most can be managed over time as your body gets used to taking this medication. People who have a history of heart, kidney, or liver problems; low blood sugar or diabetic ketoacidosis may not be good candidates for this medicine. 

Discuss all your options with your healthcare provider to determine what is best for you. 

Learn about other type 2 diabetes medications here.


What you should know about: Metformin | Harvard Health 

Everything You Always Wanted to Know About Metformin, But Were Afraid to Ask | diaTribe Learn

Metformin: medicine to treat type 2 diabetes | National Health Service UK 

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