From the FDA Drug Label
In the pool of placebo-controlled trials, gastrointestinal adverse reactions occurred more frequently among patients receiving MOUNJARO than placebo (placebo 20.4%, MOUNJARO 5 mg 37.1%, MOUNJARO 10 mg 39.6%, MOUNJARO 15 mg 43.6%). The following gastrointestinal adverse reactions were reported more frequently in MOUNJARO-treated patients than placebo-treated patients (frequencies listed, respectively, as: placebo; 5 mg; 10 mg; 15 mg): ... diarrhea (9,12,13,17)). MOUNJARO has been associated with gastrointestinal adverse reactions, which include nausea, vomiting, and diarrhea [see Adverse Reactions (6. 1)].
- Diarrhea is a common adverse reaction associated with the use of MOUNJARO, with frequencies ranging from 12% to 17% in the pool of placebo-controlled trials, compared to 9% in placebo-treated patients 1.
- The majority of reports of diarrhea occurred during dose escalation and decreased over time 1.
- MOUNJARO has been associated with gastrointestinal adverse reactions, including diarrhea, which may lead to dehydration and potentially cause acute kidney injury 1.
From the Research
Diarrhea is a common side effect of Mounjaro (tirzepatide) that typically improves over time as your body adjusts to the medication, with the highest quality evidence from 2023 and 2024 studies indicating its incidence is dose-dependent, ranging from 12% to 49% across different doses 2, 3. To manage Mounjaro-related diarrhea, start by staying well-hydrated with water and electrolyte solutions.
- Modify your diet by eating smaller, more frequent meals,
- avoiding fatty or spicy foods, and
- incorporating binding foods like bananas, rice, applesauce, and toast (BRAT diet). Over-the-counter medications such as loperamide (Imodium) can help control symptoms temporarily - take as directed on the package, typically 2mg after each loose stool, not exceeding 8mg per day. If diarrhea is severe, persistent (lasting more than 2-3 days), accompanied by fever, severe abdominal pain, or dehydration, contact your healthcare provider immediately. They may adjust your Mounjaro dose, recommend a slower titration schedule, or prescribe anti-diarrheal medications. Mounjaro causes diarrhea by slowing gastric emptying and altering gut hormone levels, which affects intestinal motility and fluid balance, as explained in the 2023 study on tirzepatide's pharmacokinetic and pharmacodynamic aspects 4. Most patients find this side effect diminishes within a few weeks of starting treatment or after dose increases, as noted in the 2022 SURPASS-5 Randomized Clinical Trial 5. The 2024 review of tirzepatide in type 2 diabetes also highlights its efficacy and safety profile, including the management of gastrointestinal side effects like diarrhea 2. Given the most recent and highest quality evidence, the management of Mounjaro-related diarrhea should prioritize hydration, dietary modifications, and, if necessary, medical intervention to minimize its impact on the patient's quality of life while maintaining the benefits of tirzepatide in managing type 2 diabetes 3.