Clinical Data & Patient Experiences
Last Updated: January 16, 2026 | Source: FDA Prescribing Information + Patient Discussion Analysis
The following adverse reactions were reported in placebo-controlled clinical trials and are listed in Zepbound's FDA-approved prescribing information.
| Adverse Reaction | Placebo | 5mg | 10mg | 15mg |
|---|---|---|---|---|
| Nausea | 8% | 25% | 29% | 28% |
| Diarrhea | 7% | 19% | 21% | 23% |
| Vomiting | 2% | 8% | 13% | 12% |
| Constipation | 5% | 17% | 15% | 11% |
| Dyspepsia | 2% | 9% | 10% | 10% |
| Fatigue | 2% | 6% | 7% | 7% |
| Abdominal Pain | 5% | 6% | 5% | 5% |
Source: FDA Prescribing Information for Zepbound (tirzepatide), Table 1
Analysis of 50,000+ posts from r/Zepbound, r/tirzepatide, r/GLP1 (2023-2026).
Note: Patient-reported data is anecdotal and may over-represent severe experiences. Not a substitute for clinical data.
Clinical: 12-18% depending on dose
Many describe nausea peaking 2-4 days post-injection, especially during dose increases. The 2.5mg→5mg transition is frequently challenging.
"Days 2-4 after my shot were rough at 5mg. Couldn't even think about food."
— r/Zepbound user
Common triggers: High-fat meals, eating past fullness, large portions
Relief strategies: Ondansetron, ginger, small frequent meals, avoiding trigger foods
Clinical: 6-7%
Unlike nausea, constipation often worsens over time. Reduced food intake (800-1200 cal/day) plus slowed GI motility creates ongoing issues.
"Nobody warned me. By week 8 I was going once a week. Daily MiraLAX is now part of my routine."
— r/Zepbound user
Management: Daily MiraLAX, magnesium citrate, fiber supplements, prevention over reaction
Clinical: Listed as "eructation" 3.0-3.3%
FDA data understates this. The "sulfur burp" or "egg burp" phenomenon is extensively discussed—burps that taste and smell like sulfur/rotten eggs, often accompanied by diarrhea.
"The sulfur burps are NO JOKE. Like rotten eggs from hell. I learned to recognize the warning signs."
— r/Zepbound user
Triggers: Fatty foods, eggs, dairy, overeating
Relief: Pepto-Bismol, Gas-X, avoiding trigger foods, smaller meals
Clinical: Not in trials; added post-marketing
Frequently discussed in patient communities. Typically appears 3-6 months after starting, likely related to rapid weight loss and caloric restriction (telogen effluvium) rather than the medication directly.
"Month 4, my hair started falling out in clumps. Terrifying but my dermatologist said it's from the rapid weight loss."
— r/Zepbound user
Common approaches: Ensure adequate protein (60-80g/day), biotin, multivitamin; usually resolves as weight stabilizes
Clinical: Not prominently reported in trials
Many patients report significant fatigue, especially in the first weeks. Often related to dramatically reduced caloric intake.
"Week 2-3 I could barely function. Then I realized I was only eating 600 calories some days."
— r/Zepbound user
Management: Track calories (minimum 1000-1200), protein shakes, electrolytes, adequate sleep
Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider.
Sources: FDA Prescribing Information, r/Zepbound, r/tirzepatide community discussions
