Normal metformin dosage: Dose for diabetes, and PCOS, and how to use it

Last Updated Sep 1, 2024

Metformin is a popular anti-diabetic medication designed for managing type 2 diabetes. However, it can also be used to manage polycystic ovary syndrome (PCOS). Learn how to use this medication and its dosage for diabetes and PCOS.

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Image showing a pack of metformin (Glucophage) 500 mg

Key takeaways:

  • Metformin was first approved for the treatment of type 2 diabetes. However, it is now also used to manage polycystic ovary syndrome. 
  • The dosage of metformin used for treating diabetes differs from the dosage used for treating polycystic ovary syndrome. However, the dosage usually starts at 500 mg, taken once or twice daily.  
  • Metformin is the preferred drug of choice for treating type 2 diabetes and is usually taken daily. Depending on the severity of the diabetic condition, metformin may be used in combination with other anti-diabetic medications. 

Metformin is popularly known as an anti-diabetic medication and is used to treat type 2 diabetes in adults and children over ten years of age. It lowers the blood sugar level and helps regulate insulin.

Metformin is also used to treat gestational diabetes in pregnant people. Gestational diabetes is a common medical condition in which a pregnant woman develops glucose intolerance.

Aside from metformin’s use in treating type 2 diabetes and gestational diabetes, it is also used to treat polycystic ovary syndrome (PCOS), a common condition in females characterized by hormonal imbalance, cysts in the ovaries, and irregular periods.

How does metformin work?

Metformin is an anti-diabetic medication that helps lower sugar levels. It belongs to a class of anti-diabetic medications called biguanides. Metformin works by decreasing glucose production by the liver and the absorption of glucose by the intestine while improving insulin sensitivity. 

Since type 2 diabetes occurs as a result of insufficient production of insulin or improper functioning of insulin, leading to high blood sugar levels, metformin is needed to reduce and control blood sugar levels. 

Metformin is typically used as the first choice in the treatment of type 2 diabetes in adults and children from 10 years of age and older.

Aside from its role in treating type 2 diabetes, metformin is also used to treat polycystic ovary syndrome (PCOS). Polycystic Ovary Syndrome (PCOS) is a condition in which an individual does not ovulate regularly.

When used in treating PCOS, metformin works by decreasing serum lipids, androgen, and insulin levels. Treatment with metformin helps improve ovulation, enabling regular menstruation.

Metformin dosage and how to use it

Metformin usually comes in different strengths. However, the common strengths are the 500 and 1000 mg, which come as standard or extended-release tablets.

The standard tablets, also called immediate-release tablets, work by lowering the blood sugar level immediately. In contrast, the extended-release tablets act slowly over a longer period of time. 

Metformin dosage depends on its use and whether the patient is a child or an adult. Here are common metformin doses for treating different conditions:

1. Metformin dosage for type 2 diabetes

For adults and children over ten years old, the dosage for treating type 2 diabetes starts at 500 mg immediate-release tablets twice daily. However, adults can also take an 850 mg daily dose with the morning meal. 

Meanwhile, the starting dose for adults on the extended-release tablets is usually 500 mg or 1000 mg, taken once daily with the evening meal. 

The extended-release tablet is not typically used in children, but a doctor determines the dose when needed.

If you are using metformin to treat diabetes, your doctor may also recommend that you exercise daily and follow a meal plan.

2. Metformin dosage for gestational diabetes

The starting dose of metformin for treating gestational diabetes is usually a 500 mg immediate-release tablet given once or twice daily. Depending on the individual’s response to the dose, a doctor might adjust the dose.

Although metformin can be used alone in pregnant people with gestational diabetes, doctors usually give it as an add-on to insulin.

In some cases, people with gestational diabetes are placed on a daily dose of up to 2500 mg of metformin.

3. Metformin dosage for PCOS

Metformin can be used alone or in combination with clomiphene to treat polycystic ovary syndrome (PCOS).

The dosage of metformin for treating PCOS usually starts at 500 mg, given once or twice daily, and can be adjusted depending on the individual’s response and tolerance level.

Metformin tablets are best taken whole. You are not to crush or chew the tablet. It should also be taken with food to avoid stomach upset and other side effects.

Common side effects to expect when taking metformin include diarrhea, loss of appetite, and vitamin B12 deficiency.

Can you lose weight on metformin?

One common side effect of metformin is weight loss. So, if you are on metformin and start to lose weight, don’t be surprised. 

However, metformin is not approved for weight loss and should not be taken solely for weight loss.

What is the maximum daily dosage for metformin?

The daily dose for metformin starts at 500 mg and is given twice daily, but can quickly go up to a maximum dose of 2000 to 2500 mg daily. 

What to do if you miss a dose of metformin

While it is not advisable to miss your medications, if you miss a metformin dose, you should take it as soon as you remember. 

However, if it’s almost time for your next dose, take the next dose instead.

Since you will be taking metformin for a long time (usually for life), you can set reminders so you never miss a dose.

When to increase your metformin dosage

Increasing metformin dosage is common for a majority of patients. However, it’s up to your doctor to decide if you should be on a higher metformin dose.

Your doctor might increase your metformin dosage if your blood sugar level is not controlled at the current dose. 

How long should you take metformin?

People taking metformin for type 2 diabetes management are usually on it for life. 

However, if your blood sugar level is no longer well controlled by metformin, or your kidney is no longer functioning properly, you should speak with a healthcare professional about an alternative or what to do.

Also, make sure your doctor knows of any other conditions you have or medications you’re taking.

Can you eat sugar while taking metformin?

It’s best to avoid foods that are high in refined sugar while taking metformin. 

Metformin helps lower blood sugar levels, while eating sugar increases blood sugar levels. Hence, eating sugar while taking metformin can be counterproductive. 

What to do if you take too much metformin

An overdose of metformin can lead to dangerously low blood sugar levels and the buildup of lactic acid, which can lead to death. Sadly, there is no antidote for metformin overdose. 

However, excess metformin can be removed from the body using hemodialysis.  

If you suspect you have overdosed on metformin, call your doctor or a healthcare provider immediately. 

Finally, it’s important to note that metformin is a prescription medication and should only be taken if a doctor has prescribed it.