Metformin: Benefits and side effects of this diabetes drug

People living with type 2 diabetes may know all about metformin, which is an oral medication taken to manage this health condition. This medicine works by lowering blood sugar levels, improving insulin sensitivity, and reducing glucose production by the liver. It is usually the first-line treatment for type 2 diabetes, as it helps control blood sugar without causing a lot of weight gain or severe hypoglycemia or low blood sugar. But that’s not the only benefit of metformin. Apart from diabetes management, this medicine, often dubbed as the “wonder drug”, is also used to treat Polycystic Ovary Syndrome (PCOS) or help to lose weight. Know the benefits and side effects of metformin, which is more than a diabetes drug.

How does metformin help diabetics?

Metformin helps people with diabetes by reducing the liver’s glucose production, improving insulin sensitivity, and decreasing glucose absorption in the intestines. “These actions lower blood sugar levels effectively, especially in people with type 2 diabetes,” says endocrinologist Dr Jaspreet Singh. It does not cause weight gain and may even aid in weight loss, making it a beneficial option for managing diabetes and preventing weight gain.

What are the health benefits of metformin?

Apart from managing diabetes, metformin has several other health benefits:

1. Aids weight loss

metformin users who lost more than five percent of their weight in the first year had more success with maintaining weight loss in years six to 15, found a study published in the Annals of Internal Medicine in 2019. “Metformin can help reduce appetite, which can lead to decreased calorie intake and ultimately, weight loss,” says the expert.

2. Helps manage polycystic ovary syndrome (PCOS)

Metformin can be used to treat PCOS, as it can significantly reduce androgen levels, improve insulin sensitivity, and regulate menstrual cycle, as per 2023 research published in the Cureus journal. This medication may also be useful in treating infertility, a common problem associated with PCOS. A study published in the journal Frontiers in Endocrinology found the positive effects of metformin on fertility. Ur was found that metformin can improve fertility outcomes in females with insulin resistance associated with PCOS.

3. Promotes heart health

Metformin may perform similar or better heart protective effects than other medicines such as pioglitazone and glyburide, as per research published in the Journal Of Cellular And Molecular Medicine in 2022. This medicine has been found to reduce the risk of myocardial infarction or heart attack, by a study published in the British Journal of Clinical Pharmacology. “It may lower blood pressure, and reduce the risk of heart disease,” says Dr Singh.

4. Reduces cancer risk

The use of this medicine may help to decrease risk of the occurrence of various types of cancers, especially of colon and pancreas, as per research published in the Annals Of Translational Medicine in 2014. Metformin contains anti-inflammatory properties may help reduce the risk of cancers.

5. Improves liver health

Metformin may be beneficial in people with non-alcoholic fatty liver disease, according to research published in the Journal of the American Pharmacists Association in 2003. “It can help to reduce liver inflammation and improve liver function,” says the expert.

6. Reduces risk of dementia

Its ability to improve insulin signaling in the brain may help to protect against cognitive decline and reduce dementia risk. An association was found between termination of metformin treatment and increased dementia incidence during a study published in JAMA Network Open in 2023.

7. Improves skin health

Metformin may have beneficial effects on inflammatory skin disorders including psoriasis, acne, and allergic contact dermatitis, as per research published in the International Journal Of Molecular Sciences in 2020. It may also help improve skin texture apart from dealing with these skin conditions.

8. Lowers the risk of long Covid

It may help to reduce the risk of long Covid in diabetics. Health records from nearly 76000 adults who took metformin for managing type 2 diabetes were analysed as part of a research published in Diabetes Care in September 2024. They were compared to more than 13000 adults who took other diabetes medications. Metformin users were up to 21 percent less likely to have long Covid than those who did not take this diabetes drug. This medicine may also help non-diabetics avoid long Covid. A study, published in The Lancet Infectious Diseases 2023, found that metformin reduced the risk of long Covid by up to 40 percent in obese or overweight adults. Most of them did not have diabetes.

What are the side effects of metformin?

Metformin has benefits, but may have some side effects too –

1. Gastrointestinal issues

These are some of the common side effects of metformin that often resolve on their own over time. They may include –

• Nausea
• Diarrhea
• Gas
• Bloating
• Loss of appetite

2. Lactic acidosis

It is rare, but dangerous illness that can cause exhaustion, muscle weakness, dyspnoea, and stomach pain. “People who drink a lot of alcohol or have specific medical disorders, like liver or renal illness, are more likely to experience this side effect,” says the expert.

3. Vitamin B12 deficiency

Metformin can interfere with the absorption of vitamin B12. This can cause anemia, which happens due to a lack of red blood cells in the body, and leads to reduced oxygen flow to the organs of the body.

Metformin is not just for diabetes management, as it helps with PCOS, weight loss, liver and heart health. But don’t consume this medicine without consulting with a doctor, as it may lead to gastrointestinal issues and more.