Metformin is one of the medications prescribed most often for type 2 diabetes as well as prediabetes. There are many misconceptions about this medication, and patients say they’ve heard bad things about it from a friend or from social media. Unfortunately, sometimes the information that they come across is inaccurate or “fake news.”

One such misleading article says that metformin is bad for you and that it is no longer being prescribed by doctors. Contrary to the article, I continue to prescribe metformin on a regular basis for my patients, a medication that continues to save lives by helping control diabetes. Many of these articles on social media end with a sales pitch at the end, selling some so-called “miracle” drug for diabetes which is not proven to work, and may even be harmful. (As a side note, never buy medications or supplements from social media sites).

Many patients ask, “Doc, di ba nakakasira yan ng kidney (Doesn’t it damage the kidney)?” The truth is that metformin does not damage the kidneys — it is uncontrolled diabetes that can cause that, or uncontrolled hypertension. But when the kidneys are not functioning well, metformin can accumulate in the body and this can lead to toxic effects. Patients with worsening kidney function are taken off metformin because of the possibility of toxicity, and this has led to the common misconception that the metformin may have been the reason for the kidney failure. Neither does metformin cause liver damage or cancer.

Guanidine

Metformin is derived from a substance called guanidine, the active ingredient in a plant called Galega officinalis (goat’s rue or French lilac) which was used to treat diabetes in medieval Europe. It has been in use since the 1950s and after advising a proper diet and exercise, it is one of the first medications prescribed for patients with type 2 diabetes mellitus, where patients have insulin resistance and cannot use insulin properly. Metformin helps your body make better use of the insulin produced by the pancreas and regulates the release of stored glucose from organs like the liver. Metformin can also be used in combination with other oral medications, injectables and insulin for better diabetes control.

When starting metformin, common side effects are stomach upset, nausea and soft bowel movements. These symptoms usually go away after a few days, but if they persist let your doctor know so you can be advised on how to adjust your medication. One way to reduce these symptoms is to start with a low dose, with a gradual increase in the dose over days to weeks. Taking the medication after a meal can also help. It is also very rare to have low blood glucose with just metformin.