Evidence review
The most common GLP-1 side effects reported in trials, who should be cautious, and how titration and clinician oversight reduce them.
Published June 1, 2026 · GLP1 One Telehealth Editorial Team
The most common GLP-1 side effects in trials are gastrointestinal — nausea, vomiting, diarrhea, and constipation — usually mild to moderate and most frequent during dose escalation. Gradual titration and clinician oversight reduce them; some people should avoid GLP-1s, so a licensed clinician should assess eligibility.
Educational use only. This article is for educational purposes only and does not provide medical advice. Compounded semaglutide and compounded tirzepatide are not FDA-approved finished drug products and should only be prescribed when clinically appropriate by a licensed healthcare provider.
Across STEP and SURMOUNT, gastrointestinal effects were the leading adverse events and generally eased after titration. Discontinuation due to side effects was relatively low but real, and varied between agents.
Slow titration, hydration, dietary adjustments, and accessible clinician support reduce the burden. Verify a program offers real oversight — see our provider checklist.
Gastrointestinal symptoms — nausea, vomiting, diarrhea, constipation — usually mild to moderate and most common during dose escalation.
People with certain conditions should not take GLP-1s; a licensed clinician should evaluate eligibility.