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%).
Diarrhea is a common adverse reaction associated with the use of MOUNJARO (tirzepatide). The frequency of diarrhea in patients treated with MOUNJARO was higher than in those treated with placebo, with reported frequencies of 12%, 13%, and 17% for the 5 mg, 10 mg, and 15 mg doses, respectively, compared to 9% for placebo 1.
- The majority of reports of diarrhea occurred during dose escalation and decreased over time.
- Gastrointestinal adverse reactions, including diarrhea, may lead to dehydration, which if severe could cause acute kidney injury 1.
From the Research
Diarrhea is a common side effect of Mounjaro (tirzepatide), affecting approximately 39-49% of patients, with the highest incidence at the 15mg dose 2. To manage Mounjaro-related diarrhea, start by staying well-hydrated with water and electrolyte solutions.
- Over-the-counter medications like loperamide (Imodium) can help control symptoms; take 2mg after each loose stool, not exceeding 8mg per day.
- Dietary modifications are also important - avoid spicy foods, caffeine, high-fat meals, and artificial sweeteners while increasing soluble fiber intake gradually. Most patients find that diarrhea improves within 4-8 weeks as the body adjusts to the medication. If diarrhea is severe (more than 6 loose stools per day), contains blood, or is accompanied by fever or severe abdominal pain, contact your healthcare provider immediately. They may recommend temporarily pausing your dose or slowing down the titration schedule. Mounjaro causes diarrhea because it slows gastric emptying and alters gut hormone signaling, which affects intestinal motility and fluid secretion, as reported in a systematic review with meta-analysis including 5 databases 2. For most patients, this side effect is temporary and manageable with these interventions, with the incidence of severe hypoglycemia, fatal adverse events, acute pancreatitis, cholelithiasis, and cholecystitis being extremely low (≤ 1%) across all doses of tirzepatide 2. The safety profile of tirzepatide is consistent with that of GLP-1 receptor agonists, indicating a potential therapeutic use in patients with type 2 diabetes 3, 4, 5. However, the most recent and highest quality study 2 suggests that gastrointestinal adverse events, including diarrhea, are dose-dependent and more frequent with higher doses of tirzepatide.