Research

Hormonal

Incretin-based anti-obesity medications (GLP-1 and GIP/GLP-1 receptor agonists) cause gastrointestinal adverse effects (nausea, diarrhea, constipation) in 65–84% of patients, primarily through delayed gastric emptying and central appetite signaling activation.

If you start a GLP-1 or GIP medication, expect stomach issues like nausea or diarrhea in the first few weeks. This is very common (affecting up to 84% of users). To manage it, start with a low dose and increase slowly. Eat small, low-fat meals, stay hydrated, and avoid spicy or fatty foods. Most symptoms improve as your body adjusts.

GoodSupportsHIGH confidence
Clinical trial data on AOMs indicate that GI AEs are reported in 65–84% of patients treated with liraglutide, semaglutide or tirzepatide... These symptoms are primarily attributed to altered gastric motility and hormone-mediated changes in appetite signaling.
Tomasz Witaszek et al. · Biomedicines · 2025

Why this rating

Based on multiple randomized controlled trials (STEP, SURMOUNT programs) and meta-analyses cited.

Source

Gastrointestinal Symptoms in Obesity Therapy: Mechanisms, Epidemiology, and Management Strategies

Tomasz Witaszek et al. · Biomedicines · 2025

DOI 10.3390/biomedicines13102362

narrative_reviewCited 2×
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DOI resolved against Crossref · corpus check 2026-06-10

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