The short answer: Ozempic slows how fast your stomach empties, so food sits there longer and you burp more. Burping is on the FDA label: 2.7% of people on 0.5 mg and 1.1% on 1 mg reported it, compared with 0% on placebo. The rotten-egg smell is thought to come from hydrogen sulfide gas made by gut bacteria. That part is a proposed explanation. No published study has measured the gas in the burps of people taking semaglutide.

How common is burping on Ozempic?

The FDA-approved Ozempic label calls burping "eructation." It lists eructation among stomach and bowel reactions that occurred in fewer than 5% of patients in the placebo-controlled trials. The rates were 0% on placebo, 2.7% on Ozempic 0.5 mg, and 1.1% on Ozempic 1 mg.

Those numbers count all burping. The label does not have a category for "sulfur burps," and the trials did not record how burps smelled. So there is no trial rate for the rotten-egg kind.

Burping is more common at the higher semaglutide dose used for weight loss. The Wegovy label reports eructation in 7% of adults on semaglutide 2.4 mg, compared with less than 1% on placebo. That is a different dose and patient group, so the rate does not transfer directly to Ozempic.

Reports sent to the FDA after approval point the same way. A 2022 analysis of the FDA adverse event database looked at 5,442 stomach and bowel reports for semaglutide. Burping gave the strongest statistical signal of the 45 it found. A signal shows a reaction is reported more often than expected. It does not show how many users get it.

Why does Ozempic make you burp more?

The established part is the slower stomach. The Ozempic label states that semaglutide "causes a delay of early postprandial gastric emptying."

Two small trials measured this effect:

The two results differ, and both trials were small. Together they support a real delay, with its size still uncertain. A stomach that holds food for longer is also a stomach that holds swallowed air and gas for longer, and gas in the stomach leaves upward. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) lists gastroparesis, a condition of slow stomach emptying, among the conditions that can lead to more gas symptoms.

Our guide to Ozempic and gastroparesis explains the difference between an expected delay and a diagnosed emptying disorder.

Where does the sulfur smell come from?

The rotten-egg smell is the smell of hydrogen sulfide. Gut bacteria make this gas. A 2017 review of sulfur and the gut microbiome describes two main routes. Sulfate-reducing bacteria make hydrogen sulfide from sulfate. Other bacteria make it when they break down cysteine, a sulfur-containing amino acid found in protein.

The NIDDK says the odor of gas passed from the other end "may be due to sulfur." The proposed link to Ozempic is that food held longer in the stomach and upper gut gives bacteria more time to work on it, and some of that gas comes up as a burp.

Nobody has tested that link directly. Here is what is known and what is not:

  • Established: Ozempic delays stomach emptying, and burping is a labeled reaction.
  • Established: gut bacteria make hydrogen sulfide, and it smells like rotten eggs.
  • Proposed only: that slower emptying on Ozempic raises hydrogen sulfide in burps. No published study has measured it.
  • Unknown: why some people get sulfur burps and others on the same dose do not.

One more piece of research is early. A 2025 database study of adults with type 2 diabetes found more diagnoses of small intestinal bacterial overgrowth in the first year on GLP-1 drugs than on other diabetes drugs (hazard ratio 2.14). The absolute rates were very low, under 0.2 cases per 1,000 patient-years. The study did not look at burping.

When do sulfur burps start, and do they go away?

The Ozempic label says that most reports of nausea, vomiting, and diarrhea occurred during dose escalation. The label does not give timing for burping on its own.

The Wegovy label does group burping with other stomach reactions and says these "were most frequently reported during dosage escalation." The 2022 FDA database analysis also found that stomach and bowel reports clustered early in treatment, and that the risk appeared to fall over time.

This suggests burping is most likely in the weeks after you start or after a dose increase. No study has followed sulfur burps over time, so there is no verified number for how long they last.

What can help sulfur burps on Ozempic?

No trial has tested a treatment for sulfur burps in people taking semaglutide. The steps below come from general NIDDK advice on gas and from the label.

  • Swallow less air. The NIDDK suggests limiting gum, hard candy, fizzy drinks, and drinking through a straw. It also names eating quickly as a habit that adds swallowed air.
  • Look for trigger foods. The NIDDK says high-fat foods can cause more gas symptoms. Its list of gas-forming foods includes cruciferous vegetables, beans, and dairy products. Many people blame eggs, red meat, and protein shakes because they are rich in sulfur. That fits the biology, but no study has tested it for Ozempic burps. A food diary can show your own pattern.
  • Follow the dose steps. The label says to follow its dose escalation "to reduce the risk of gastrointestinal adverse reactions." If burps start after an increase, tell your prescriber.
  • Ask a pharmacist about simethicone. MedlinePlus says simethicone treats gas symptoms such as pressure, fullness, and bloating. It is not known to change the smell.
  • Know the limits of bismuth subsalicylate. Bismuth binds hydrogen sulfide. In a 1998 study of 10 healthy adults, it cut hydrogen sulfide release from stool samples by more than 95%. That study looked at the colon and did not look at burps. MedlinePlus lists its uses as diarrhea, heartburn, and upset stomach. It says to ask a doctor or pharmacist first if you take medication for diabetes or are allergic to aspirin.

Burps often come with other stomach symptoms. Our Ozempic nausea tips cover meal size and timing. If the burps bring acid or a burning feeling, see our guide to Ozempic and heartburn. Tirzepatide and other drugs in this class cause the same complaint, and our sister site glp1.md covers sulfur burps across all GLP-1 drugs.

When are sulfur burps a sign of something more serious?

Sulfur burps alone are not a known danger sign. Burps with other symptoms are the concern. The NIDDK lists "too much belching" as one symptom of gastroparesis, along with feeling full long after a meal, nausea, vomiting, bloating, and upper abdominal pain. The Ozempic label says the drug is not recommended in people with severe gastroparesis.

The NIDDK advises seeking medical care right away for any of these:

  • severe pain or cramping in your abdomen
  • vomiting for more than an hour
  • red blood in your vomit, or vomit that looks like coffee grounds
  • blood glucose levels that are too high or too low
  • feeling extremely weak or fainting
  • fever or difficulty breathing

Do not stop Ozempic on your own. Talk with your prescriber first.

The bottom line

Ozempic causes burping in a small share of people: 1.1% to 2.7% in the label's trials, compared with 0% on placebo. The cause that is well supported is slower stomach emptying. The sulfur smell most likely comes from hydrogen sulfide made by gut bacteria, but no study has confirmed that in people taking semaglutide. Severe pain, repeated vomiting, or blood in vomit needs medical care right away.

Last updated: October 2026. This article is for informational purposes only and does not constitute medical advice. Talk with your prescriber or pharmacist before you change your Ozempic dose or add an over-the-counter remedy for burping.