Ozempic and Mounjaro Sulfur Burps: Causes, Label Data and Red Flags
Why Ozempic, Wegovy and Mounjaro cause sulfur (rotten-egg) burps: slowed stomach emptying, label rates for burping, when it eases, red flags and user stories.
Anonymous user report. Not medical advice. Peptides discussed are not FDA-approved for the uses described. Editorial process →
Short answer
Sulfur burps are burps that taste or smell like rotten eggs. They are a common complaint on GLP-1 drugs such as Ozempic and Wegovy (semaglutide) and Mounjaro and Zepbound (tirzepatide). These drugs slow how fast the stomach empties, so food, especially protein and other sulfur-rich foods, sits longer and more gas forms. Burping (eructation in label language) is a listed side effect on all four labels, and it is usually worst in the first weeks and after dose increases. Not medical advice. Peptide Confessions does not publish dosing, timing, injection or sourcing guidance. Facts checked October 23, 2026.
Burping on the labels
Labels count burping, not the smell, so "sulfur burps" as such are not measured. From the US prescribing information on DailyMed (Ozempic, Wegovy, Mounjaro, Zepbound) and the Canadian Wegovy monograph:
| Drug | Burping in trials | Placebo |
|---|---|---|
| Ozempic (semaglutide, diabetes) | 2.7% on the lower dose, 1.1% on the higher dose | 0% |
| Wegovy (semaglutide, weight loss) | 7% (US label); 7.4% (Canadian monograph) | Under 1%; 0.4% in Canada |
| Mounjaro (tirzepatide, diabetes) | 2.5% to 3.3% across doses | 0.4% |
| Zepbound (tirzepatide, weight loss) | 4% to 5% across doses | 1% |
Why GLP-1 drugs cause rotten-egg burps
GLP-1 drugs act as a brake on the stomach. Slower emptying helps people feel full, but food stays in the stomach longer. Endocrinologists quoted by Medscape in April 2026 explained that sulfur-rich foods such as protein, eggs and cruciferous vegetables then have more time to break down, and that longer contact with gut bacteria increases fermentation and hydrogen sulfide, the gas behind the rotten-egg smell. People who already have reflux, slow stomach emptying, IBS or small intestinal bacterial overgrowth may be more prone. Higher doses and faster dose increases bring more stomach side effects in general.
What real-world reports show
Burping is one of the strongest signals in adverse-event databases for both drugs. In US FDA reports for semaglutide from 2018 to 2022, eructation had the highest reporting odds ratio of 45 stomach-related signals (Shu 2022), and most stomach effects appeared early and eased over time. For tirzepatide, a 2025 analysis counted 500 burping reports (ROR 46.56), with a median onset of 23 days for side effects overall (Chen 2025). These databases count complaints, not rates. A 2026 Canadian review for dentists (Kofman & Ouanounou, Canadian Journal of Diabetes) lists belching and reflux among semaglutide's effects and notes knock-on mouth effects such as bad breath and dry mouth.
How long do sulfur burps last?
Labels say stomach side effects were most common during dose escalation and decreased over time, and the Canadian Wegovy monograph describes most stomach events as mild or moderate and short. Many users describe burps settling after the first weeks, then sometimes returning after a dose increase. In our archive, #190 says the rotten-egg burps of the first month on tirzepatide calmed down around week six.
What clinicians commonly suggest
- —Smaller, slower meals and stopping before feeling full, since the stomach empties more slowly.
- —Having the largest protein meals earlier in the day, rather than late at night.
- —Cutting back on the usual triggers: eggs, red meat, broccoli and other cruciferous vegetables, garlic, fizzy drinks, alcohol and very fatty meals.
- —Staying hydrated and taking a short walk after meals.
- —Asking a pharmacist or prescriber about over-the-counter options and about the treatment plan itself. Any change to the medicine is the prescriber's call.
When burps are a red flag
Burping on its own is usually harmless. Get medical help for severe or persistent stomach pain (especially pain spreading to the back, which can signal pancreatitis), repeated vomiting, being unable to keep fluids down, signs of dehydration, a swollen hard belly or no bowel movements, or pain in the upper right abdomen with fever or yellowing skin. The labels warn about pancreatitis, gallbladder disease and severe stomach problems, and say these drugs are not recommended in severe gastroparesis (see Ozempic and pancreatitis and Ozempic and gastroparesis). Persistent sulfur burps with bloating and diarrhoea can also point to bacterial overgrowth, which a clinician can test for. If you have a procedure needing anaesthesia, tell the team you take a GLP-1 drug.
What users report here
Burping comes up in several of our anonymous confessions (checked October 23, 2026). #190 describes a first month on tirzepatide of burps that "tasted like rotten eggs" that eased by about week six. #298 lists nausea, vomiting, constipation and burping in a rough first month on semaglutide. #774, who moved on from tirzepatide, noticed burps waking them at night only when dinner was after 8 pm. Stories, not rates. More on the tirzepatide hub and in Canada on Mounjaro side effects in Canada.
Related topics
data reports:
related peptides:
in Canada:
community guides:
More confessions from the archive
Community Q&A
- Why does Ozempic cause sulfur burps?
- Semaglutide slows stomach emptying, so food, especially protein and sulfur-rich foods, sits longer and ferments, producing hydrogen sulfide, which smells like rotten eggs.
- Does Mounjaro cause sulfur burps?
- Burping is on the Mounjaro label (2.5% to 3.3% vs 0.4% placebo) and the Zepbound label (4% to 5% vs 1%). Tirzepatide slows stomach emptying in the same way.
- Are sulfur burps worse on Wegovy than Ozempic?
- Burping was more common in the Wegovy weight-loss trials (7% vs under 1% placebo) than the Ozempic diabetes trials (1.1% to 2.7% vs 0%).
- How long do sulfur burps last on Ozempic or Mounjaro?
- Labels say stomach effects peak during dose increases and ease over time. Many users describe improvement after the first weeks.
- What foods trigger sulfur burps on GLP-1 drugs?
- Clinicians most often name eggs, red meat, cruciferous vegetables such as broccoli, garlic, fizzy drinks, alcohol and fatty meals.
- When should I worry about sulfur burps?
- Seek care for severe or persistent abdominal pain, repeated vomiting, dehydration, a swollen belly or fever with upper-right pain.
- Does this page give dosing advice?
- Peptide Confessions does not publish dosing, timing, injection or sourcing guidance.
Sources
Last reviewed November 11, 2026. Anonymous first-hand reports plus sourced context — educational only, not medical advice. Editorial policy & corrections.