Research

Hormonal

GLP-1 receptor agonists (GLP-1 RAs) induce significant gastrointestinal adverse events (nausea, vomiting, diarrhea, constipation) by slowing gastric emptying and increasing gastric accommodation, with incidence rates ranging from 18% to 52% depending on the specific agent and dose.

If you are prescribed a GLP-1 drug like semaglutide or liraglutide, expect a high chance of nausea or vomiting, especially when starting. The paper advises starting at the lowest dose and increasing slowly. Crucially, you must adjust your diet: eat smaller meals, reduce fat, and avoid raw fiber. If you continue to have side effects, ask your doctor about dose de-escalation. Do not assume the sickness is what causes the weight loss; the drug works directly, but the side effects are a common hurdle to manage.

GoodSupportsHIGH confidence
The most common reported adverse effects (AEs) with these incretin RAs are gastrointestinal symptoms that include nausea, vomiting, diarrhea, and constipation... In the SUSTAIN 10 trial with SQ semaglutide, 52% patients reported gastrointestinal AEs compared to 35% in the placebo group... Oral semaglutide (approved for treatment of T2DM), 25mg and 50mg per day, was associated with nausea in 27% and vomiting in 18% of patients.
Michael Camilleri et al. · The American Journal of Gastroenterology · 2023

Why this rating

Based on multiple randomized controlled trials (SUSTAIN, PIONEER, SURMOUNT) and meta-analyses cited in the review.

Source

Effects of GLP-1 and Other Gut Hormone Receptors on the Gastrointestinal Tract and Implications in Clinical Practice

Michael Camilleri et al. · The American Journal of Gastroenterology · 2023

DOI 10.14309/ajg.0000000000002519

narrative_reviewCited 30×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →