GLP-1 drugs slow stomach emptying, which lets food sit longer and ferment. Gut bacteria break down sulfur-containing proteins and release hydrogen sulfide gas—the same compound that gives rotten eggs their smell. It's temporary, usually improving within 4-8 weeks.
What Are Sulfur Burps?
Sulfur burps are burps that smell like rotten eggs. The distinctive odor comes from hydrogen sulfide (Hâ‚‚S), a gas produced when bacteria in the digestive tract break down sulfur-containing compounds.
While sulfur burps aren't specifically listed in FDA prescribing information for semaglutide, the mechanism of the drug—particularly delayed gastric emptying—creates conditions that promote this symptom. In clinical trials:
| Medication | Burping Incidence |
|---|---|
| Ozempic 0.5 mg | 3% of patients |
| Ozempic 1 mg | 1% of patients |
| Wegovy (semaglutide) | 2.7% of patients |
| Mounjaro (tirzepatide) | Higher than placebo (not specified) |
Note: Clinical trials reported "burping" or "eructation"—not specifically sulfur burps. But the mechanism explains why many patients experience the sulfur odor.
The Science: How GLP-1s Cause Sulfur Burps
GLP-1 receptor agonists like semaglutide work by mimicking a natural hormone (GLP-1) that regulates blood sugar, reduces appetite, and—critically—slows gastric emptying.
🔬 The Step-by-Step Mechanism
- Delayed gastric emptying: GLP-1 drugs slow the movement of food from stomach to intestines
- Extended fermentation time: Food sits in the stomach longer than normal
- Bacterial breakdown: Gut bacteria have more time to ferment sulfur-containing proteins
- Hydrogen sulfide production: Bacteria release Hâ‚‚S gas as a byproduct
- Gas release: Accumulated gas escapes through belching (or flatulence)
Research shows that slowing gut transit decreases fecal sulfate—meaning more sulfate remains in the gut, available for bacterial metabolism and hydrogen sulfide production.
Additional Contributing Factors
- Microbiome changes: GLP-1 drugs may alter gut bacteria composition, potentially favoring species that produce hydrogen sulfide
- Dietary changes: Patients adjusting their diets may inadvertently increase sulfur-rich foods
- Existing conditions: GERD, small intestinal bacterial overgrowth (SIBO), or gastroparesis can worsen symptoms
High-Sulfur Foods to Watch
Hydrogen sulfide is generated when bacteria ferment sulfur-containing proteins and compounds. These foods are particularly high in sulfur:
| Food Category | Examples |
|---|---|
| Alliums | Garlic, onions, leeks, shallots |
| Cruciferous vegetables | Broccoli, cabbage, cauliflower, Brussels sprouts |
| Protein sources | Eggs, red meat, poultry, fish |
| Dairy | Cheese, milk, yogurt |
| Legumes | Beans, lentils |
| Preserved foods | Dried fruits, wine, beer |
This doesn't mean you should eliminate these foods—many are nutritious. But temporarily reducing intake while your body adjusts to GLP-1 medication may help.
How Long Do Sulfur Burps Last?
Like most GI side effects of GLP-1 drugs, sulfur burps are typically temporary:
If symptoms persist beyond 8-12 weeks, or are severe, consult your healthcare provider. They may recommend slowing titration, temporarily reducing the dose, or evaluating for other conditions.
Evidence-Based Relief Strategies
âś“ Dietary Modifications
- Reduce high-sulfur foods temporarily (eggs, garlic, onions, cruciferous vegetables)
- Eat smaller, more frequent meals to reduce fermentation time
- Avoid carbonated beverages which add gas to your digestive tract
- Limit gas-producing foods like beans, lentils, and high-fiber foods
- Stay hydrated—water helps move food through your digestive tract faster
- Eat slowly to reduce swallowed air
âś“ Over-the-Counter Options
- Bismuth subsalicylate (Pepto-Bismol) can bind sulfide. Note: Avoid if allergic to aspirin or taking blood thinners.
- Activated charcoal may absorb intestinal gases. Separate from other medications by 2+ hours.
- Ginger provides mild relief for nausea and digestive discomfort
- Peppermint tea may help, but avoid if you have GERD (can worsen symptoms)
- Simethicone (Gas-X) for general gas relief
âś“ Lifestyle Adjustments
- Walk after meals to promote gastric motility
- Don't lie down immediately after eating
- Avoid tight-fitting clothing around your abdomen
- Limit straws and chewing gum (increases swallowed air)
When to See a Doctor
⚠️ Seek Medical Attention For
- Severe persistent abdominal pain (especially if radiating to back)
- Persistent vomiting
- Jaundice (yellowing of skin or eyes)
- Fever
- Inability to pass stool or gas
- Abdominal distension
These could indicate serious complications such as pancreatitis, gallbladder disease, or intestinal obstruction.
For persistent sulfur burps that don't improve after 8-12 weeks despite dietary modifications, your healthcare provider may:
- Adjust your GLP-1 medication dosage
- Slow the titration schedule
- Refer you to a gastroenterologist
- Evaluate for conditions like SIBO, gastroparesis, or H. pylori infection
Different GLP-1 Drugs: Does It Matter?
Individual responses vary. If one GLP-1 drug causes intolerable sulfur burps, switching to a different one may help—though all GLP-1 agonists slow gastric emptying to some degree.
Tirzepatide (Mounjaro/Zepbound) is a dual GLP-1/GIP agonist, which may have different GI tolerability profiles for some patients. However, burping was still reported more commonly with tirzepatide than placebo in clinical trials.
The Bottom Line
Sulfur burps on GLP-1 medications are unpleasant but not dangerous. They result from a predictable mechanism: slowed gastric emptying leads to extended fermentation of sulfur-containing foods by gut bacteria, producing hydrogen sulfide gas.
The good news is that symptoms typically improve within 4-8 weeks as your body adjusts. In the meantime, dietary modifications—particularly reducing high-sulfur foods and eating smaller meals—can provide significant relief.
Never adjust your GLP-1 medication dosage without consulting your healthcare provider. If symptoms are severe or persistent, they can help determine whether dosage adjustment or further evaluation is needed.
Sources
- SingleCare. "Ozempic sulfur burps and diarrhea: Causes and treatment." SingleCare. September 2025.
- Fella Health. "Can Semaglutide Cause Sulfur Burps? Causes and Management." Fella Health. August 2025.
- Drugs.com. "Do GLP-1 drugs like Ozempic or Mounjaro cause sulfur burps?" Drugs.com. September 2025.
- Ro. "Ozempic Sulfur Burps and Diarrhea: Causes, Treatment." Ro. June 2025.
- Healthline. "Mounjaro Sulfur Burps: Possible Causes and Tips for Relief." Healthline. August 2025.
- Ro. "Wegovy Sulfur Burps: Why They Happen and How to Treat Them." Ro. September 2025.
- Blachier F, et al. "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.
- FDA. Ozempic (semaglutide) prescribing information. FDA.gov.
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