Sulfur burps
Clinical reviewer: Jacob Moore, MD · Last checked September 24, 2026
What are sulfur burps?
Sulfur burps is an informal name for belching that smells unpleasant. The medical term for belching is eructation, and belching itself is a normal process that releases air from the stomach. GLP-1 medication labels list eructation as a side effect, reported more often on the drug than on placebo in trials.
What is belching, and what is it called medically?
Belching is the act of bringing up air from the stomach, and it is a normal process whose purpose is to release that air [1]. The term sulfur burps is an informal, unofficial name for belching that smells unpleasant; the medical term for belching itself is eructation. These sources do not explain what causes the smell, so none is described here.
How often does it happen on GLP-1 medications?
Trial data list eructation as a side effect at higher rates on GLP-1 medications than on placebo: 7% versus under 1% on Wegovy 2.4 mg [2], and 4-5% versus 1% on Zepbound [3]. In an analysis of FDA adverse event reports (FAERS) covering 5,442 semaglutide gastrointestinal cases, eructation was the strongest of 45 disproportionality signals found, ranging from 1.01 for hypoaesthesia oral up to 42.03 for eructation [4].
Frequently asked questions
What is the medical term for a sulfur burp?+−
The medical term is eructation, which simply means belching. Belching is a normal process for releasing air from the stomach; these sources don't identify what causes any particular smell.
Does everyone on a GLP-1 medication get sulfur burps?+−
No. Trial data show it affecting a minority: about 7% on Wegovy 2.4 mg versus under 1% on placebo, and 4-5% on Zepbound versus 1% on placebo.
Related terms
Sources
- MedlinePlus — Belching
- WEGOVY (semaglutide) injection, solution; tablet — Full Prescribing Information
- ZEPBOUND (tirzepatide) — FDA Prescribing Information
- Shu Y et al. Gastrointestinal adverse events associated with semaglutide, A pharmacovigilance study based on FDA adverse event reporting system. Front Public Health, 2022.
This entry is for education and is not medical advice. Talk with a licensed clinician about your own situation before starting, stopping, or changing any treatment.
