Definition
Hydrogen sulfide is a gas that smells like rotten eggs. Gut bacteria make it from sulfur in food, and it is the likely source of the sulfur burp smell. The GLP-1 labels list burping as a side effect but do not mention sulfur burps by name.
In the gut, hydrogen sulfide comes mostly from bacteria breaking down sulfur-containing substances from food. The colon lining can use small amounts as fuel, while larger amounts can irritate it. People notice the gas when it comes up as a burp or passes as gas with that rotten-egg odor.
GLP-1 medicines slow the stomach (see gastric emptying), so food and gas linger longer. The labels report more burping, called eructation: 7% of adults on Wegovy 2.4 mg vs less than 1% on placebo, and 4% to 5% on Zepbound vs 1%. They do not break out sulfur burps, so the link to hydrogen sulfide is an explanation, not a label finding. Sulfur burps together with vomiting or diarrhea deserve more attention; see the answers below.
At GLP-1 SOS, sulfur burps are one of the reasons we made GLP-1 SOS Daily Gut Relief: ginger, peppermint, a 19-strain probiotic blend and digestive enzymes, 2 capsules with dinner, to support digestive comfort.*
*GLP-1 SOS Daily Gut Relief supports regular bowel movements and digestive comfort. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
In the Lab
- Why do I get sulfur burps on a GLP-1?
- Sulfur burps with diarrhea or vomiting: is it normal?
- Gas and burping on a GLP-1: normal or a problem?
- Is bloating normal on a GLP-1?
From the people behind the Lab
You do not have to figure this out alone.
GLP-1 SOS is the daily companion made for life on a GLP-1. Plain answers like this one, a support team that replies to real questions from real people, and daily formulas like GLP-1 SOS Daily Gut Relief, designed around the side effects that come with the medication. The GLP-1 Lab is our free education arm: no login, no paywall, no hype. Side effects are part of the road. Suffering through them is not.
Sources (4)
- Hydrogen Sulfide, ToxFAQs. Agency for Toxic Substances and Disease Registry (ATSDR), CDC.
- Production of hydrogen sulfide by the intestinal microbiota and epithelial cells and consequences for the colonic and rectal mucosa. American Journal of Physiology: Gastrointestinal and Liver Physiology, 2021.
- Wegovy (semaglutide) injection and tablets, Prescribing Information. Novo Nordisk / FDA, revised June 2026.
- Zepbound (tirzepatide) injection, Prescribing Information. Eli Lilly, revised August 2026.
Reviewed by the GLP-1 SOS editorial team · Education, not medical advice · Talk to your prescriber about your dose and your symptoms.
