Mounjaro and Diarrhea: How to Manage This Common Side Effect

Non-insulin injectable medications that help to improve blood sugar levels have been growing in popularity. Mounjaro (Tirzepatide) is one of these medications. It’s FDA-approved to treat Type 2 diabetes. 

Mounjaro is a glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist. Its unique mechanism of action makes it the only medication in its class. 

Mounjaro can help deliver powerful blood sugar control. But it can also cause some unpleasant side effects. Many people experience gastrointestinal side effects, like vomiting, indigestion, and bowel changes, when they start taking Mounjaro. If you’ve been having diarrhea while taking Mounjaro, here’s what you need to know.

Does Mounjaro cause diarrhea?

Yes, Mounjaro can cause diarrhea. In studies, about 12% to 17% of people taking tirzepatide had diarrhea.

Some people experienced diarrhea without any other symptoms. But others reported other gastrointestinal symptoms too, including:

• Nausea 

• Low appetite

• Vomiting

• Indigestion

• Constipation

• Stomach pain

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In clinical trials, people were more likely to have diarrhea if they were taking higher doses of tizepatide. Researchers also found that diarrhea was more common when their tizepatide dose was increased. 

Researchers also noticed these patterns in people taking Zepbound. Zepbound is another form of tizepatide that’s FDA-approved for weight management and treatment of sleep apnea in adults who are considered obese.

In studies, most people reported that diarrhea from Mounjaro was mild. And most people preferred to keep taking Mounjaro even if they had diarrhea. This suggests that the benefits of Mounjaro outweighed the drawbacks of having diarrhea. 

How long does Mounjaro-related diarrhea last?

It’s not clear how long Mounjaro-related diarrhea lasts. In clinical trials, researchers noted that diarrhea slowly went away once people reached their goal dose of Mounjaro. But they didn’t specify how long this took. 

Why does Mounjaro cause diarrhea?

Researchers are still learning how tirzepatide causes gastrointestinal side effects like diarrhea.

One theory is that diarrhea develops because the tirzepatide changes how your gut digests food. It may lower how much carbohydrates and nutrients your body absorbs from food. And when carbohydrates aren’t fully absorbed, they can make stool softer and looser. 

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These absorption changes may also affect your gut microbiome. Imbalances in your gut microbiome can cause diarrhea. 

But more research is needed to know for sure if these changes directly cause Mounjaro-related diarrhea.

How do you treat diarrhea caused by Mounjaro?

Most of the time, Mounjaro-related diarrhea will go away on its own. But this won’t happen until you’ve been on your goal dose for a little while. It can take time for your body to adjust to the medication. 

In the meantime, here are some things you can do to ease mild to moderate diarrhea.

1. Stay hydrated

Drink plenty of fluids to avoid dehydration. Water is your best option if your diarrhea is mild. You can also try electrolyte drinks. These help replace the fluids and electrolytes that you lose in diarrhea. Just be sure to pick options that are low in sugar. Drinks with too much sugar can worsen diarrhea. 

2. Choose foods that are easy on your gut

It’s a good idea to avoid foods that worsen Mounjaro side effects. Foods that are greasy or high in fat often make diarrhea worse. Greasy, fatty foods can also worsen Mounjaro-related nausea and indigestion. You may also want to avoid ultra-processed or spicy foods, which can also worsen gut side effects from Mounjaro. Instead, try eating:

• Cooked eggs

• Lean meats

• Low-fat dairy options

• Cooked vegetables

• Soft fruits 

These foods are usually easier on your gut.

3. Avoid coffee and alcohol

There’s evidence that alcohol and coffee can make people poop more often. Try avoiding these drinks until your diarrhea settles down. 

4. Try an over-the-counter (OTC) medication

There are over-the-counter (OTC) medications that can help ease diarrhea like Pepto-Bismol (bismuth subsalicylate). But it’s important to check with your healthcare team before you take OTC medications. They aren’t safe for everyone and may make some Mounjaro side effects worse. 

You can also try taking probiotics or eating probiotic-rich foods. This can help keep your gut microbiome healthy. 

Can you prevent diarrhea when taking Mounjaro?

There’s no way to fully prevent diarrhea when taking Mounjaro. 

Some experts recommend starting with a low dose and then slowly increasing it to your target dose. Taking a slower approach may help some people avoid diarrhea. But there aren’t any studies showing whether this works for everyone. Going slow may also help with other Mounjaro-related side effects. But going slow also means that it can take longer to see improvements in your blood sugar.

Work with your healthcare team to find the right middle ground. This can help you stay comfortable while also getting the benefits of Mounjaro. 

When should you seek care for Mounjaro-related diarrhea?

Most people will experience mild diarrhea when taking Mounjaro. And diarrhea will improve with time. 

But some people may have more severe diarrhea. It’s important to get medical care if this happens. Severe diarrhea can lead to dehydration and other medical problems.

Contact your healthcare team right away if you:

• Have more than four stools per day

• Notice your diarrhea is getting worse over time

• Have stomach pain along with diarrhea

• See blood in your stool

• Can’t eat or drink

• Feel dizzy or lightheaded when you stand up

• Have chest pain or a rapid heartbeat

• Are making less urine than normal

• Notice your urine looks darker than normal

• Faint

Why trust our experts?

Written by:

Meredith Grace Merkley, DO, FAAP

Dr. Merkley is a licensed, board-certified pediatrician who has over a decade of experience working in community health. She is currently a National Health Services Corp scholar, and is serving as the medical director of a school-based health clinic at a federally funded health center.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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