Burping and sulfur burps on GLP-1 medications

Eructation, not sulfur

Eructation is the medical word for belching or burping. It appears in section 6.1 of every label covered here, and the Wegovy® and Zepbound® Medication Guides list belching among the most common side effects ^[1][8].

We searched the full text of the Wegovy®, Ozempic®, Rybelsus®, Saxenda®, Mounjaro®, Zepbound® and Foundayo™ prescribing information, and the Mounjaro® and Zepbound® Medication Guides, for “sulfur” and “sulphur”. Neither word appears in relation to belching. The phrase “sulfur burps” comes from people describing their experience, not from the labels, which describe belching but not its smell or taste.

Belching rates against placebo

Each row comes from the label’s placebo-controlled trials. Ranges cover dose groups, and section 6.1 of each label warns that rates from different trials cannot be directly compared.

What the Wegovy label adds

In the Wegovy® adult weight trials, belching is one of a group of stomach reactions that occurred more often than on placebo, alongside indigestion, abdominal pain, bloating, gas, reflux, gastritis, hemorrhoids and hiccups. The label says these reactions were most frequently reported while the dose was being increased. In its trial of adolescents aged 12 and older, belching was reported by 4% on Wegovy® and none on placebo ^[1].

The neighbouring entries in the Wegovy® table give context: indigestion (dyspepsia) 9% against 3% on placebo, bloating (abdominal distension) 7% against 5%, gas (flatulence) 6% against 4%, and reflux 5% against 3% ^[1].

European and Canadian product information

European package leaflets list burping as common, meaning up to 1 in 10 people, for Ozempic®, Wegovy®, Mounjaro® and Saxenda®, and as uncommon, up to 1 in 100, for Rybelsus® tablets ^[10][11].

The Canadian monographs, revised in June 2026, give the figures by dose. For Zepbound®, belching was reported by 3.8%, 5.5% and 5.1% on 5, 10 and 15 mg against 0.6% on placebo; for Mounjaro® in its placebo-controlled diabetes pool, 3.0%, 2.5% and 3.3% against 0.4%, matching the US label ^[12].

Why it might happen

• What the labels say: nothing about a cause. They state that semaglutide and tirzepatide delay gastric emptying, but they do not connect that to belching, and we did not find that connection tested in the sources used here ^[1][5].
• What public health sources explain about belching in general: NIDDK describes it as releasing gas from the stomach through the mouth, and says some people belch a lot because they swallow too much air. Chewing gum, sucking hard candy, fizzy drinks, drinking through a straw, eating fast and talking while eating all increase swallowed air ^[13][14].
• About the smell: MedlinePlus says most gas has no odor and that the smell comes from bacteria in the large intestine releasing small amounts of sulfur-containing gases; NIDDK makes the same point about passed gas ^[13][15]. Neither source discusses the smell of belches, so this is background rather than an explanation of “sulfur burps”.

Other possible causes

NIDDK notes that some people get more gas symptoms after cruciferous vegetables such as broccoli and cauliflower, beans, peas and lentils, foods high in fibre, fructose or lactose, and sugar-free products sweetened with ingredients ending in “-ol”. Conditions such as celiac disease, irritable bowel syndrome, lactose intolerance and bacterial overgrowth in the small intestine can also cause gas symptoms ^[14].

Belching can also travel with other stomach problems. NIDDK lists “too much belching” among the symptoms of gastroparesis, together with early fullness, nausea, vomiting and upper abdominal pain ^[13]. If belching comes with those, it is worth describing the whole picture rather than the belching alone.

What general guidance says helps

• Swallow less air: NIDDK lists avoiding chewing gum and hard candy, skipping fizzy drinks and straws, not talking while eating, eating more slowly and sitting down to eat ^[14]. MedlinePlus adds drinking water and non-fizzy drinks ^[15].
• Meals: NIDDK says a doctor may suggest smaller, more frequent meals and eating less of the foods and drinks that seem to increase your symptoms. Noting which meals come before belching makes that conversation easier ^[14].
• Medicines and supplements: NIDDK says doctors may recommend over-the-counter medicines in some cases and asks you to talk with your doctor before using supplements or probiotics. The GLP-1 Medication Guides also ask you to tell your provider about every medicine and supplement you take ^[6][8][14].

What to write down

Belching is easier to discuss with specifics. Note the days it happens and how many days after your injection, whether it follows particular meals and what they were, and how you would describe the smell or taste in your own words. Record any nausea, bloating, heartburn or stomach pain on the same days, and whether your dose recently went up, since that is when the Wegovy® label says stomach reactions were most frequent.

A short run of notes shows whether belching is tied to meals, to a point in your dosing week or to dose changes, and whether it is fading. That is more useful to your clinician than a search-engine label for the symptom.

Wegovy®, Ozempic®, Rybelsus® and Saxenda® are registered trademarks of Novo Nordisk A/S. Mounjaro® and Zepbound® are registered trademarks and Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Novo Nordisk or Eli Lilly and Company.

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