Yes, Metformin Can Cause Diarrhea. Here’s What You Can Do

Metformin is sometimes referred to as a wonder drug because of its ability to help those with diabetes and cardiovascular issues. While the drug is extremely helpful in controlling blood sugar levels, metformin diarrhea is a common and unfortunate side effect. In this post we’ll look at some of the reasons for metformin diarrhea, how long it typically lasts, and steps you can take to help mitigate the effects. 

Why does metformin cause diarrhea?

We don’t know exactly why metformin can cause diarrhea. One possible explanation of metformin diarrhea has to do with chemicals in the gut. Because metformin works to control blood sugar in the stomach, imbalances in gut chemicals like serotonin and histamine can potentially lead to diarrhea.

Another possible cause of metformin diarrhea has to do with our gut biome. Metformin can alter the bacteria and viruses that naturally exist in our gut. This potentially disrupts the way our gut functions and can lead to loose and more frequent bowel movements as your body adjusts to the medication.

Does diarrhea from Metformin go away?

For many people, diarrhea is most common during the first few weeks of starting metformin. Those early weeks can be challenging. In one study, around 5% of people stopped taking metformin because of gut-related side effects. The good news? These issues usually improve as time goes on. However, if your issues persist it’s best to discuss it with your healthcare provider. They can recommend ways to help control the issue or possibly adjust your dosage as needed.

Here’s what you can do to ease Metformin diarrhea:

Make sure to take with food

Because side effects are more common on an empty stomach, the best way to reduce the chance of metformin diarrhea is to take the medication with food. If you happen to forget your dose and need to take it between meals, even something as simple as a healthy, low-carb snack can help reduce the likelihood of side effects.

While taking metformin with a meal can help ease diarrhea symptoms, it’s also a good idea to avoid taking it with meals that are overly greasy or sugary. These types of foods can worsen diarrhea symptoms.

Switch to Extended Release (ER)

There are two common formulations of Metformin: immediate release (IR) and extended release (ER or XR). As the names imply, the IR formulation releases the medication more quickly into your body than the ER option. Switching to an extended release dose of metformin can help ease discomfort and reduce the likelihood and symptoms of metformin diarrhea.

Adjust your dosage (low and slow)

If you’re just starting a treatment plan that includes metformin, you can discuss a graduated approach to your dosage with your healthcare provider. Both the IR and ER formulations of metformin can cause diarrhea if the initial dosage is too high, so a low and slow approach is often recommended. 

A typical dose starts around 500mg taken with meals once or twice each day. Rapidly increasing your dose can make metformin diarrhea effects worse, as your body won’t have adequate time to adjust to increased amounts of the medicine.

Talk with your Doctor 

As with any medication, it’s best to keep open and honest lines of communication with your healthcare provider. Let’s face it, diarrhea can be a frustrating and sometimes embarrassing symptom to discuss, but your healthcare team is there to help you reach your goals and do so in as comfortable of a way as possible.

The Takeaway

Diarrhea is a fairly common side effect of taking metformin, with as many as 53% of patients reporting diarrhea on the immediate release formulation. That said, there are ways to mitigate or even eliminate your issues with diarrhea while taking metformin, including adjusting the dosage, formulation, and way you take the drug. 

Of course, the ultimate way to avoid metformin diarrhea is to reverse your diabetes so you no longer have to take the drug. If that sounds interesting to you, Virta Health may be able to help. By making healthy lifestyle changes in a medical setting with supportive resources like 1:1 virtual coaching, you can regain control of your health and feel like yourself again. See if you’re eligible for Virta Health here.