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Safety7 min readMarch 16, 2025
Why Does Mounjaro Cause Diarrhea?
Understanding the mechanism behind tirzepatide-related diarrhea. Why it happens and effective management strategies.
By Med Consumer Watch Team
Diarrhea is a common side effect of Mounjaro (tirzepatide), especially during dose increases. Here's why it happens and how to manage it.
The Mechanism
Why tirzepatide affects bowels:
• GLP-1 effects on gut motility - Alters how food moves through intestines
• GIP effects - May contribute to GI symptoms
• Gallbladder effects - Changes in bile release can cause loose stools
• Dietary changes - Eating differently affects digestion
• Fat malabsorption - Possible in some people
When It Typically Occurs
Diarrhea patterns:
• Most common during dose increases
• Often improves after several weeks at stable dose
• May recur when titrating up
• Usually decreases over time as body adjusts
If diarrhea is severe during dose increases, discuss slower titration with your provider.
Management Strategies
To reduce diarrhea:
- Stay hydrated - Replace lost fluids
- Avoid fatty foods - Can worsen symptoms
- Limit caffeine and alcohol
- Consider BRAT diet temporarily (bananas, rice, applesauce, toast)
- Probiotics may help some people
- Avoid sugar alcohols (sorbitol, xylitol)
When to Contact Your Provider
Seek medical attention if:
• Severe or persistent diarrhea
• Signs of dehydration
• Blood in stool
• Fever
• Unable to keep fluids down
• Diarrhea prevents normal activities
Severe diarrhea can cause dangerous dehydration. Don't ignore persistent symptoms.
The Bottom Line
Diarrhea on Mounjaro results from the medication's effects on gut function. It's typically most pronounced during dose increases and often improves with time. Stay hydrated, adjust diet as needed, and contact your provider if symptoms are severe or persistent.
Sources & References
- FDA - Mounjaro Prescribing Information
Medical Disclaimer
This article is for informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare provider before making decisions about your health or medications. Individual experiences may vary.