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By Knowridge

Metformin is widely used to lower blood sugar in type 2 diabetes, and research suggests it may also offer benefits beyond that main job. Its long history of use has also revealed side effects that range from digestive discomfort to less common but important complications.

Understanding both sides matters because diabetes affects much more than a blood test result.

Over time, high blood sugar can damage blood vessels and organs, while people with diabetes also face an increased risk of heart problems.

Metformin has been prescribed for decades, so its effects are supported by both clinical trials and experience in routine care.

Some proposed benefits are still being investigated, making it important to separate its established use in diabetes from other possibilities.

Metformin reduces the amount of sugar released by the liver and helps the body respond more effectively to insulin.

Insulin is the hormone that allows sugar to move from the blood into cells, where it can be used for energy.

One important trial, published in The Lancet in 1998, studied intensive blood sugar control in overweight people with newly diagnosed type 2 diabetes.

The metformin group had a 39% lower relative risk of heart attack than the group receiving the conventional treatment policy, which mainly involved diet.

That figure describes a comparison between specific groups in a particular trial.

It does not mean that every person taking metformin gains the same protection, or that the drug reduces every form of heart disease by 39%.

Research on other diabetes medicines is also examining kidney and lung protection beyond lowering blood sugar; those results should not be assumed to apply to metformin.

Metformin can also have a favorable effect on weight compared with some diabetes treatments that cause weight gain. Some people lose a modest amount, but the response varies and blood sugar management remains its principal purpose.

Researchers have investigated possible effects on inflammation, the body’s response to injury or infection.

Such work may help explain some of metformin’s wider actions, but it does not establish the medicine as a general treatment for inflammation or cancer.

The most familiar side effects involve the digestive system, including nausea, diarrhea and stomach discomfort. These may ease with time, although some people continue to find them troublesome.

Long-term use can reduce vitamin B12 levels by affecting absorption.

A shortage of this vitamin can contribute to tiredness, nerve problems and anemia, a condition in which the blood cannot carry oxygen as effectively as it should.

A very rare complication is lactic acidosis, a dangerous build-up of lactic acid in the body.

Serious kidney problems can increase the risk because the medicine may not be cleared properly.

Metformin alone does not usually cause low blood sugar, although the risk can change when it is combined with other diabetes medicines.

Its wider benefits are worth studying, but they do not remove the need to consider kidney function, other treatments and the side effects associated with continued use.