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Sulfur burps on a GLP-1: what the labels call it and what helps

Updated Sep 30, 2026. Numbers in brackets link to the source each fact comes from.

The FDA labels do not use the words “sulfur burps.” They record burping as eructation, and the Zepbound medication guide translates it for patients as belching [1]. It was reported more often on every GLP-1 medicine than on placebo, but in far fewer people than nausea. What the labels do not say is anything about the smell, so the “sulfur” part is not something the FDA data can confirm or explain.

How often burping was reported

For the three weight-loss medicines, burping is a row in the side-effect table. Column order comes from each label’s header.

Medicine and trial group Placebo On the medicine
Zepbound 5, 10 and 15 mg, weight trials 1% 4%, 5%, 5% [2] [3]
Wegovy injection 2.4 mg, weight trials under 1% 7% [4] [5]
Foundayo 5.5, 9 and 17.2 mg, weight trials 1% 6%, 8%, 8% [6] [7]
Ozempic 0.5 and 1 mg, diabetes trials 0% 2.7%, 1.1% [8]
Mounjaro 5, 10 and 15 mg, diabetes trials 0.4% 3.0%, 2.5%, 3.3% [9]

What stands out is the placebo column: almost nobody on a dummy shot or pill reported burping, so nearly all of the figure on the drug side is the gap between the two groups. The Wegovy tablet trial had side effects similar in type and frequency to the injection table [10]. These trials enrolled different people, so the rows do not rank the drugs.

Heartburn and indigestion sit close by. On Zepbound, gastroesophageal reflux disease was reported by 4% to 5% of people, against 2% on placebo [11]. Full tables are on the pages for Zepbound, Wegovy, Foundayo, Ozempic and Mounjaro.

Why it might happen, and how long it lasts

The labels do not explain why burping happens on these drugs. They do say both tirzepatide and semaglutide slow how fast the stomach empties [13] [14]. For tirzepatide, the slowing is largest after the first dose and becomes smaller over time [13]. The Wegovy label lists burping among the gut reactions that were most often reported while the dose was being raised [12]. No label gives a number of weeks.

MedlinePlus lists heartburn and burping among the semaglutide side effects to tell your doctor about if they are severe or do not go away [15].

What helps, according to NIDDK

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) says some burping is normal; people typically belch up to 30 times a day [16]. It becomes a problem when it happens often, bothers you or gets in the way of daily life [17]. Its general advice for frequent belching focuses on swallowing less air:

  • Skip chewing gum and hard candy.
  • Avoid fizzy drinks and drinking through a straw.
  • Try not to talk while eating or drinking.
  • Eat more slowly, and sit down to eat when you can [19].
  • Eat smaller, more frequent meals, and cut back on the foods and drinks that make your gas worse [20].

NIDDK also says to talk with a doctor before trying supplements or probiotics for gas [21]. None of this advice is written for GLP-1 medicines.

About the smell

NIDDK says an unpleasant smell in passed gas (flatus) may be due to sulfur [18]. It does not say the same about burps, and none of the GLP-1 labels mentions the smell of belching.

One published review does name the problem. A 2025 review in the journal Obesity Pillars lists sulfur burps, meaning belching that smells of hydrogen sulfide, among the rare or poorly understood side effects of GLP-1 treatment that still need study [25]. It mentions possible causes, such as slower stomach emptying, bacterial overgrowth in the small intestine and sulfur in the diet, but says direct evidence is lacking [26].

When to call a doctor

NIDDK says to talk with a doctor if gas symptoms bother you [22]. Burping alone is not listed as a serious reaction, but the medication guides list warning signs that can come with upper stomach symptoms:

  • Gallbladder problems. Pain in your upper stomach, fever, yellow skin or eyes, or clay-colored stools [23].
  • Pancreatitis. Severe stomach pain that will not go away, with or without nausea or vomiting, sometimes reaching the back; stop the medicine and call right away [24].

Sources

  1. The most common side effects of ZEPBOUND include: nausea diarrhea vomiting constipation stomach (abdominal) pain indigestion injection site reactions feeling tired allergic reactions belching hair loss heartburn dailymed.nlm.nih.gov, read Sep 27, 2026.
  2. Adverse Reaction Placebo (N=958) % ZEPBOUND 5 mg (N=630) % ZEPBOUND 10 mg (N=948) % ZEPBOUND 15 mg (N=941) % dailymed.nlm.nih.gov, read Sep 27, 2026.
  3. Eructation 1 4 5 5 dailymed.nlm.nih.gov, read Sep 27, 2026.
  4. Placebo N=1,261 % WEGOVY Injection (2.4 mg Once Weekly) N=2,116 % dailymed.nlm.nih.gov, read Sep 27, 2026.
  5. Eructation <1 7 dailymed.nlm.nih.gov, read Sep 27, 2026.
  6. Adverse Reaction Placebo (N=1,576) % FOUNDAYO 5.5 mg once daily (N=1,051) % FOUNDAYO 9 mg once daily (N=1,055) % FOUNDAYO 17.2 mg once daily (N=1,049) % dailymed.nlm.nih.gov, read Sep 27, 2026.
  7. Eructation 1 6 8 8 dailymed.nlm.nih.gov, read Sep 27, 2026.
  8. In addition to the reactions in Table 1, the following gastrointestinal adverse reactions with a frequency of <5% were associated with OZEMPIC (frequencies listed, respectively, as: placebo; 0.5 mg; 1 mg): dyspepsia (1.9%, 3.5%, 2.7%), eructation (0%, 2.7%, 1.1%) dailymed.nlm.nih.gov, read Sep 27, 2026.
  9. The following gastrointestinal adverse reactions were reported more frequently in MOUNJARO-treated adult patients than placebo-treated patients (frequencies listed, respectively, as: placebo; 5 mg; 10 mg; 15 mg): eructation (0.4%, 3.0%, 2.5%, 3.3%) dailymed.nlm.nih.gov, read Sep 27, 2026.
  10. In the clinical trial with WEGOVY 25 mg tablets, the types and frequency of common adverse reactions were similar to those listed in Table 3. dailymed.nlm.nih.gov, read Sep 27, 2026.
  11. Gastroesophageal Reflux Disease 2 4 4 5 dailymed.nlm.nih.gov, read Sep 27, 2026.
  12. Other reactions that occurred at a higher incidence among WEGOVY injection-treated adult patients included dyspepsia, abdominal pain, abdominal distension, eructation, flatulence, gastroesophageal reflux disease, gastritis, hemorrhoids, and hiccups. These reactions were most frequently reported during dosage escalation. dailymed.nlm.nih.gov, read Sep 27, 2026.
  13. Tirzepatide delays gastric emptying. The delay is largest after the first dose and this effect diminishes over time. dailymed.nlm.nih.gov, read Sep 27, 2026.
  14. Semaglutide delays gastric emptying. dailymed.nlm.nih.gov, read Sep 27, 2026.
  15. Semaglutide injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away: nausea, vomiting, diarrhea stomach pain constipation heartburn, burping medlineplus.gov, read Sep 27, 2026.
  16. Belching, or burping, is a release of gas from your stomach through your mouth. People typically belch up to 30 times a day. niddk.nih.gov, read Sep 27, 2026.
  17. Gas symptoms may be a problem if they occur often, bother you, or affect your daily activities. niddk.nih.gov, read Sep 27, 2026.
  18. The odor may be due to sulfur in the flatus. niddk.nih.gov, read Sep 27, 2026.
  19. Swallowing less air may help ease gas symptoms, especially if you belch a lot. Your doctor may recommend you avoid chewing gum and sucking on hard candy avoid drinking fizzy drinks and drinking with a straw avoid talking while eating or drinking eat more slowly and, when you can, sit down to eat instead of eating on the run niddk.nih.gov, read Sep 27, 2026.
  20. For example, your doctor may recommend eating smaller, more frequent meals or consuming less of the foods and drinks that increase your gas symptoms. niddk.nih.gov, read Sep 27, 2026.
  21. For safety reasons, talk with your doctor before using supplements, probiotics, or any complementary or alternative medicines or medical practices. niddk.nih.gov, read Sep 27, 2026.
  22. You should talk with your doctor if gas symptoms bother you. niddk.nih.gov, read Sep 27, 2026.
  23. Gallbladder problems have happened in some people who use ZEPBOUND. Tell your healthcare provider right away if you get symptoms of gallbladder problems which may include: pain in your upper stomach (abdomen) fever yellowing of skin or eyes (jaundice) clay-colored stools dailymed.nlm.nih.gov, read Sep 27, 2026.
  24. Stop using WEGOVY and call your healthcare provider right away if you have severe pain in your stomach area (abdomen) that will not go away, with or without nausea or vomiting. Sometimes you may feel the pain from your abdomen to your back. dailymed.nlm.nih.gov, read Sep 27, 2026.
  25. Moreover, rare or poorly understood adverse effects such as, sulfur burps (eructation with hydrogen sulfide odor) warrant mechanistic investigation. pmc.ncbi.nlm.nih.gov, read Sep 28, 2026.
  26. Hypotheses include medication-induced delayed gastric emptying, small intestinal bacterial overgrowth, and dietary sulfur load, but direct evidence is lacking. pmc.ncbi.nlm.nih.gov, read Sep 28, 2026.

This page reports what official sources say; it is not medical advice. Medical disclaimer.