Mounjaro (tirzepatide) is a relatively new medication used primarily for managing type 2 diabetes and, more recently, for weight loss. Developed by Eli Lilly, this drug is part of a growing class of medications known as GLP-1 (glucagon-like peptide-1) receptor agonists, with dual action on GIP (glucose-dependent insulinotropic polypeptide) receptors. While Mounjaro has shown impressive results in blood sugar regulation and weight management, it is not without side effects. One of the most commonly reported gastrointestinal side effects is constipation.

This article will explore whether Mounjaro causes constipation, why it happens, how common it is, and what can be done to manage it effectively.

Understanding Mounjaro and How It Works

Mounjaro functions by mimicking two important hormones, GLP-1 and GIP. These hormones play a crucial role in:

• Stimulating insulin secretion
• Slowing gastric emptying (the rate at which food leaves the stomach)
• Reducing appetite
• Regulating blood sugar levels

By slowing down digestion and gastric emptying, Mounjaro helps patients feel fuller for longer, reducing overall calorie intake and contributing to weight loss. However, this slowed digestion can also contribute to gastrointestinal side effects, including nausea, bloating, and constipation.

Does Mounjaro Cause Constipation?

Yes, constipation is a known side effect of Mounjaro. Clinical trials and patient reports indicate that constipation is among the most frequently experienced gastrointestinal issues for people taking this medication.

How Common is Constipation with Mounjaro?

According to clinical studies conducted by Eli Lilly, gastrointestinal side effects, including nausea, diarrhea, and constipation, were reported in a significant percentage of participants. Specifically:

• Constipation affected approximately 6-8% of patients using Mounjaro at various doses.
• This side effect was generally mild to moderate in severity.
• It often occurred in the initial weeks of treatment and subsided as the body adjusted.

While constipation is not as common as nausea (which affects a higher percentage of users), it is still a frequent complaint among those using the medication.

Why Does Mounjaro Cause Constipation?

The main reason Mounjaro can cause constipation is its effect on the digestive system. Here are a few key factors that contribute to this side effect:

1. Slowed Gastric Emptying
   • Mounjaro works by slowing down digestion, which can lead to less frequent bowel movements.
   • Food stays in the stomach longer, which may delay stool formation and movement through the intestines.
2. Decreased Food Intake
   • Because Mounjaro helps reduce appetite, many users consume fewer calories and fiber.
   • A lower food intake means less waste material, which can contribute to constipation.
3. Changes in Gut Motility
   • The way Mounjaro interacts with gut hormones may affect how efficiently the intestines push stool forward.
   • Reduced motility can lead to harder, drier stools that are difficult to pass.
4. Dehydration
   • Some patients on Mounjaro may experience nausea and vomiting, leading to reduced fluid intake.
   • Lack of hydration can contribute to constipation by making stools harder.

Other Gastrointestinal Side Effects of Mounjaro

While constipation is a concern, Mounjaro can cause other digestive issues, including:

• Nausea: The most commonly reported side effect, which often improves over time.
• Diarrhea: Some patients experience loose stools instead of constipation.
• Bloating and Gas: Due to slowed digestion, bloating and excess gas may occur.
• Vomiting: In some cases, nausea progresses to vomiting, though this is less common.

These symptoms are typically mild to moderate and often improve as the body adjusts to the medication.

Who is at Higher Risk for Constipation on Mounjaro?

Certain individuals may be more prone to experiencing constipation while using Mounjaro, including:

• People with a history of constipation: Those who already struggle with constipation may find it worsens on Mounjaro.
• Low-fiber eaters: A diet low in fiber can exacerbate digestive issues.
• Dehydrated individuals: Not drinking enough water can make constipation worse.
• Sedentary individuals: Physical activity plays a role in gut motility, and those who are less active may experience more constipation.
• Higher doses of Mounjaro: Higher doses tend to have more pronounced side effects, including gastrointestinal issues.

How to Manage and Prevent Constipation While Taking Mounjaro

Fortunately, there are several ways to reduce or prevent constipation while using Mounjaro:

1. Increase Fiber Intake

• Fiber adds bulk to stool, making it easier to pass.
• Aim for 25-30 grams of fiber daily from foods like:
  • Fruits (apples, berries, pears)
  • Vegetables (broccoli, spinach, carrots)
  • Whole grains (oats, brown rice, quinoa)
  • Legumes (beans, lentils, chickpeas)
• If dietary fiber is insufficient, fiber supplements (like psyllium husk) may help.

2. Stay Hydrated

• Drink at least 8-10 cups of water per day to soften stool.
• Herbal teas and water-rich foods (cucumber, watermelon) can also help.
• Avoid excessive caffeine or alcohol, which can contribute to dehydration.

3. Exercise Regularly

• Physical activity stimulates bowel movements.
• Aim for at least 30 minutes of moderate exercise (walking, jogging, yoga) most days of the week.

4. Establish a Routine

• Set a regular schedule for bowel movements, ideally after meals.
• Don’t ignore the urge to go, as delaying can lead to harder stools.

5. Consider Stool Softeners or Laxatives (if necessary)

• If dietary changes don’t help, over-the-counter stool softeners or mild laxatives may be beneficial.
• Options include:
  • Osmotic laxatives (MiraLAX, magnesium citrate) to draw water into the intestines.
  • Stool softeners (Colace) to ease passage.
• Avoid long-term use of stimulant laxatives (like Senna), which can lead to dependence.

6. Talk to Your Doctor

• If constipation becomes severe or persistent, a healthcare provider can recommend alternative strategies or adjust the dosage of Mounjaro.

When to Seek Medical Attention

While mild constipation is common and manageable, certain symptoms may indicate a more serious issue. Contact a healthcare provider if you experience:

• Severe or prolonged constipation (lasting more than a week despite interventions)
• Severe abdominal pain or cramping
• Bloating with no bowel movements for several days
• Vomiting along with constipation
• Blood in the stool or black, tarry stools

These could indicate complications such as an intestinal blockage or severe dehydration.

Alternatives to Mounjaro if Constipation is Severe

For some individuals, the side effects of Mounjaro may be too disruptive. If constipation or other digestive issues become unbearable, alternative medications may be considered, such as:

• Ozempic (semaglutide): Another GLP-1 receptor agonist with similar effects but a different tolerance profile.
• Trulicity (dulaglutide): Works similarly but may cause fewer gastrointestinal issues in some individuals.
• Metformin: A first-line treatment for type 2 diabetes that can be used alone or in combination with other medications.

Consult a healthcare provider to discuss alternatives if side effects become unmanageable.

Conclusion

Mounjaro is a highly effective medication for managing type 2 diabetes and promoting weight loss, but it does come with gastrointestinal side effects, including constipation. This occurs due to slowed digestion, reduced food intake, and changes in gut motility.

While constipation is common, it can often be managed with simple lifestyle changes, such as increasing fiber intake, staying hydrated, exercising regularly, and establishing a routine. In some cases, stool softeners or laxatives may be necessary.

If constipation becomes severe or persistent, it’s important to consult a healthcare provider to discuss treatment options or possible medication adjustments. With the right strategies, most people can continue benefiting from Mounjaro while minimizing its digestive side effects.

References

1. Eli Lilly and Company. (2023). Mounjaro (tirzepatide) prescribing information. Retrieved from https://www.lilly.com
2. American Diabetes Association (ADA). (2023). Standards of medical care in diabetes—2023. Diabetes Care, 46(Suppl 1), S1-S264. DOI: 10.2337/dc23-S001
3. U.S. Food and Drug Administration (FDA). (2022). Mounjaro approval and safety profile. Retrieved from https://www.fda.gov
4. Mayo Clinic. (2023). Type 2 diabetes: Medications and side effects. Retrieved from https://www.mayoclinic.org
5. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). (2023). Gastrointestinal side effects of GLP-1 receptor agonists. Retrieved from https://www.niddk.nih.gov
6. ClinicalTrials.gov. (2022). A study of tirzepatide in participants with type 2 diabetes. Retrieved from https://clinicaltrials.gov
7. Johns Hopkins Medicine. (2023). Constipation: Causes, symptoms, and treatments. Retrieved from https://www.hopkinsmedicine.org
8. Harvard T.H. Chan School of Public Health. (2023). Dietary fiber and its role in digestion. Retrieved from https://www.hsph.harvard.edu
9. American Gastroenterological Association (AGA). (2023). Understanding constipation and treatment options. Retrieved from https://www.gastro.org
10. Cleveland Clinic. (2023). How to relieve constipation: Lifestyle changes and medical interventions. Retrieved from https://my.clevelandclinic.org

These references provide scientific backing for the information discussed, ensuring accuracy and credibility. If you need further details or direct links to studies, let me know!