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Do GLP-1 drugs like Ozempic and Mounjaro cause sulfur burps?

Medically reviewed by Kristianne Hannemann, PharmD. Last updated on May 14, 2025.

Official Answer by Drugs.com

Yes, GLP-1 drugs such as Ozempic and Mounjaro cause sulfur burps in some individuals by slowing digestion, leading to food fermentation and hydrogen sulfide gas buildup. This gas produces the characteristic rotten-egg smell of sulfur burps. While uncomfortable, this side effect is typically temporary and manageable.

What Are GLP-1 Drugs and How Do They Work?

GLP-1 drugs, also known as GLP-1 receptor agonists, are a class of medications primarily used to treat type 2 diabetes and obesity. They mimic the action of a natural hormone called glucagon-like peptide-1 (GLP-1), which is released in the gut after eating. Common examples include semaglutide (Ozempic, Wegovy), liraglutide (Victoza, Saxenda), and tirzepatide (Mounjaro, Zepbound).

What Are Sulfur Burps?

Sulfur burps are burps that have a distinct foul, rotten egg smell. This odor is caused by the presence of hydrogen sulfide (H₂S) gas, which is produced when bacteria in the digestive tract break down certain foods or as a result of specific gastrointestinal conditions. Sulfur burps can occur naturally, but GLP-1 drugs make them more likely due to their effect on digestion.

Why Do GLP-1 Drugs Like Ozempic and Mounjaro Cause Sulfur Burps?

Eructation, or burping, is listed as a side effect in the FDA-approved package inserts for many GLP-1 drugs. GLP-1 drugs delay stomach emptying, causing food to stay in the stomach longer. This leads to fermentation and gas production, which can cause more burping. The gas that causes sulfur-smelling burps is hydrogen sulfide.

In one study, patients taking a GLP-1 drug were more likely to test positive for gases produced by bacteria in the gastrointestinal tract. This suggests that slowed digestion from GLP-1 drugs can lead to more fermentation and gas production in the GI tract. This excess gas typically comes out through belching or flatulence.

Which GLP-1 Drugs Are Most Likely to Cause Sulfur Burps?

Individual responses to different GLP-1 drugs vary. If one GLP-1 drug is causing side effects such as burping, it may be worth trying a different one. In clinical studies, burping was reported as a side effect with most GLP-1 drugs:

Mounjaro and Zepbound belong to a class of medications called dual GLP-1/GIP agonists. They’re generally more potent than GLP-1 agonists due to their mechanism of action. This means they might also cause more side effects, like burping. Similar to GLP-1 agonists, stomach-related side effects tend to be worse when first starting the medication and get better over time.

Related questions

Are Sulfur Burps a Sign the Medication Is Working?

No. Sulfur burps are a side effect of slowed digestion, not an indicator of treatment effectiveness of GLP-1 drugs for blood sugar control or weight loss. Some people may experience sulfur burps, while others do not, and the absence or presence of this symptom does not correlate with how well the drug is controlling blood sugar or supporting weight loss.

There are many possible causes of sulfur burps, which may not be related to the medication. Other causes of sulfur burps include dietary factors, digestive conditions like irritable bowel syndrome and gastroesophageal reflux disease, and lifestyle habits.

How to Reduce or Stop Sulfur Burps While Taking GLP-1 Drugs

Several strategies can help minimize how much you burp while taking a GLP-1 drug. These include:

Dietary Recommendations

Lifestyle Adjustments

Medical Solutions

When to Contact Your Doctor

If sulfur burps persist, worsen, or are accompanied by other severe symptoms (such as vomiting, severe abdominal pain, or diarrhea), speak with your healthcare provider. They may adjust your GLP-1 dosage or recommend alternative treatments.

Most of the time, burping and other stomach-related side effects improve over the first few weeks of taking a GLP-1 drug. If symptoms last longer than a few weeks after starting treatment, tell your healthcare provider.

Final Takeaway

While sulfur burps are unpleasant, rest assured they are generally temporary and manageable. GLP-1 drugs may cause more burping as a side effect due to slowed digestion. Consult your healthcare provider for persistent or bothersome symptoms.

References
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  10. Rizvi, A. A., et. al. 2022. The Emerging Role of Dual GLP-1 and GIP Receptor Agonists in Glycemic Management and Cardiovascular Risk Reduction. Diabetes, metabolic syndrome and obesity : targets and therapy, 15, 1023–1030. https://doi.org/10.2147/DMSO.S351982
  11. Saxenda [package insert]. Updated 2024. Novo Nordisk. Accessed on May 14, 2025 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3946d389-0926-4f77-a708-0acb8153b143
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