Mounjaro Sulphur Burps and Ozempic Burping, Rates and Remedies

Sulphur burps (sulfur burps in US spelling) are burping, or eructation, with an eggy smell. The US Mounjaro label reports burping in 2.5 to 3.3% of people versus 0.4% on placebo (Mounjaro label, section 6.1), and the Wegovy 2.4 mg label reports 7% versus under 1% (Wegovy label, Table 3). No label measures the smell, and the stomach slowing blamed for it is largest after the first dose and then fades (Mounjaro label, section 12.2).

Key facts

• In the Zepbound weight trials, burping affected 4 to 5% of people versus 1% on placebo, and wind and bloating 3 to 4% versus 2% (Zepbound label, Table 1).
• The UK SmPCs list burping, wind and bloating as common, meaning at least 1 in 100 but fewer than 1 in 10 people (Mounjaro, Ozempic and Wegovy SmPCs, section 4.8).
• After a first Mounjaro 5 mg dose, a paracetamol test dose peaked 50% lower and 1 hour later, and by week 4 there was no meaningful effect (Mounjaro label, section 12.3).
• Pepto-Bismol lists belching among its uses, and its label caps it at 8 doses in 24 hours and asks people on diabetes medicines or blood thinners to check first (Pepto-Bismol Drug Facts).
• Acute pancreatitis, listed as uncommon (up to 1 in 100 people), shows as severe stomach pain that will not go away, and it means you stop the injection and get urgent help (Mounjaro leaflet).

How common are sulphur burps on Mounjaro, Ozempic, Zepbound and Wegovy?

No US label mentions the smell (Mounjaro label, section 6.1), so the nearest figures are burping (eructation) rates, from 1.1% on Ozempic 1 mg to 8% on Foundayo 9 mg and 17.2 mg. The table sets each dose against placebo in the same trials, from the Mounjaro, Zepbound, Ozempic, Wegovy and Foundayo labels.

The Mounjaro and Ozempic figures come from type 2 diabetes trials and the rest from weight-loss trials, and the Wegovy label warns that rates from different drugs' trials "cannot be directly compared". Burping and bloating are missing for Wegovy 7.2 mg because its table lists only reactions seen in at least 2% and more often than on both 2.4 mg and placebo (Wegovy label, Table 4).

The UK Mounjaro, Ozempic and Wegovy SmPCs list burping, wind and bloating as common, meaning at least 1 in 100 but fewer than 1 in 10 people. The UK Mounjaro leaflet lists "Burping (eructation)" as common, which it defines as "may affect up to 1 in 10 people" (Mounjaro leaflet). In SURPASS-CVOT, an active-comparator trial with no placebo arm, 5.4% on tirzepatide reported burping (Mounjaro SmPC, section 4.8).

Why does Mounjaro cause sulphur burps?

The leading explanation is that tirzepatide slows stomach emptying, giving bacteria longer to make eggy-smelling gas, but only the slowing appears in the label (Mounjaro label, section 12.2). A PubMed search on 9 November 2026 found no published study of sulphur burps with tirzepatide, semaglutide, liraglutide or orforglipron (PubMed search). Eggy burps are also a listed symptom of an unrelated gut infection, giardiasis (NHS giardiasis page).

Semaglutide, the medicine in Ozempic, also causes "a delay of early postprandial gastric emptying" (Ozempic label, section 12.2). The usual suspect for the eggy smell is hydrogen sulphide, which a 1998 study called "one of the main malodorous compounds in human flatus" (Suarez and colleagues). Bacteria in the large intestine use meat protein to make it (Magee and colleagues).

When five healthy men ate diets with 0 g to 600 g of meat a day for 10 days each, the sulphide in their stool rose from 0.22 to 3.38 mmol/kg (Magee and colleagues). That meat study measured the large intestine, not the stomach.

When are sulphur burps worst, and how long do they last?

No label reports how long burping lasts or which day it peaks, but the stomach slowing blamed for it is largest after the first dose (Mounjaro label, section 12.2). After a first Mounjaro 5 mg dose, a paracetamol test dose peaked 50% lower, and at week 4 there was no meaningful effect (Mounjaro label, section 12.3). The Zepbound label reports a 55% drop after the first 5 mg dose and no meaningful effect at week 6 on 15 mg (Zepbound label, section 12.3).

In the Zepbound trials, most nausea, vomiting and diarrhoea came during dose escalation and decreased over time (Zepbound label, section 6.1). In Wegovy’s STEP UP trials, stomach side effects were most often reported in the first 20 weeks (Wegovy SmPC, section 4.8).

Tirzepatide reaches its peak blood level a median of 24 hours after each injection, within a range of 8 to 72 hours (Zepbound label, section 12.3). Semaglutide peaks 1 to 3 days after the dose (Ozempic label, section 12.3). Enter your dose and injection day in the GLP‑1 plotter to see where your estimated level peaks in the days after a shot.

To see whether bad days cluster after each shot, log any nausea, heartburn, diarrhoea or constipation that comes with the burps in Pensday, each with a severity. Its patterns view lines up each day’s worst severity for the past week under the estimated medication-level curve, with your last dose day marked. Pensday has no burping or bloating option, so record the burps in the shot log’s free text note, and the food log keeps what you ate that day. Symptom logging, the patterns view, the shot-log note and the food log are in the free tier, and AI food scanning is Pensday Plus.

How do you stop sulphur burps on Mounjaro or Ozempic?

Start with smaller meals eaten slowly and fewer fizzy drinks and less beer, which is the NHS advice for wind. No remedy has been tested against sulphur burps on these medicines (PubMed search). The table sorts each tip by its evidence from the NHS, the meat and bismuth studies, Pepto-Bismol Drug Facts and the Wegovy SmPC.

If stomach side effects make a new dose hard to take, the UK Wegovy SmPC says to consider "delaying dose escalation or lowering to the previous dose until symptoms have improved" (Wegovy SmPC, section 4.2). The US Wegovy label allows a delay of 4 weeks (Wegovy label, section 2.2), and the Zepbound label, which covers tirzepatide, the medicine in Mounjaro, allows a lower maintenance dose (Zepbound label, section 2.1). If the burps began after an Ozempic step-up, read about going back a dose in stepping up Ozempic.

Before moving your shot to bedtime, read when to inject Ozempic, morning or night. After a big dinner, use the steps in overeating on Ozempic.

Does Pepto-Bismol help sulphur burps on Mounjaro?

Pepto-Bismol’s US label lists "gas", "belching" and "fullness" from overindulgence among its uses (Pepto-Bismol Drug Facts), but no study has tested it for sulphur burps on Mounjaro (PubMed search). In 10 healthy people, bismuth subsalicylate 524 mg four times a day for 3 to 7 days cut the hydrogen sulphide released from stool by more than 95% (Suarez and colleagues). The study measured the colon, not burps, in people not taking GLP‑1 medicines.

The label sets the liquid’s dose at 30 mL (525 mg) every half hour as needed, with no more than 8 doses (240 mL) in 24 hours (Drug Facts). It contains salicylate, so skip it if you are allergic to aspirin or other salicylates. Ask a pharmacist or doctor first if you take any medicine for diabetes, blood thinning, gout or arthritis (Drug Facts).

It can darken your stool or tongue, which is harmless, but do not use it if you already have black or bloody stool, an ulcer or a bleeding problem. Stop and ask a doctor if your symptoms get worse or last more than 2 days (Drug Facts).

Why do sulphur burps come with diarrhoea or vomiting?

No study has looked at why eggy burps can come before diarrhoea or vomiting (PubMed search), but all three are side effects of the same medicines. In the Zepbound weight trials, 56% of people on each dose had a stomach or bowel side effect, against 30% on placebo (Zepbound label, section 6.1).

Diarrhoea, nausea and vomiting can dehydrate you and lead to kidney problems, so tell your doctor right away if they do not go away (Mounjaro Medication Guide). For what to eat and drink in the meantime, follow what to eat with GLP‑1 diarrhoea.

Eggy burps with smelly diarrhoea, wind and bloating are also symptoms of giardiasis, a gut infection (NHS giardiasis page). You can catch it from contaminated water, food or drinks, including water swallowed while swimming in lakes, rivers or pools. In the UK, ask for an urgent GP appointment or call 111 if diarrhoea lasts more than 7 days (NHS giardiasis page). Mention any recent travel abroad, since a GP may test a stool sample and antibiotics treat it.

For reflux, a separate common side effect (Mounjaro SmPC, section 4.8), follow the reflux steps in the GLP‑1 nausea guide.

When are sulphur burps a reason to get help?

Burping is listed among the common, non-serious side effects (Mounjaro leaflet), but stop Mounjaro, Zepbound or Ozempic and get help right away for severe stomach pain that will not go away (Zepbound Medication Guide). That pain, with or without vomiting and sometimes felt through to your back (Zepbound Medication Guide), can mean pancreatitis, which the UK leaflet lists as uncommon, affecting up to 1 in 100 people (Mounjaro leaflet).

Tell your doctor right away about these as well:

• pain in your upper stomach, fever, yellowing of your skin or eyes, or clay-coloured stools, which can mean gallbladder problems (Zepbound Medication Guide)
• vomiting or diarrhoea that does not go away, because fluid loss can lead to kidney problems (Mounjaro Medication Guide)
• severe constipation with stomach ache, bloating and vomiting, which the UK Wegovy leaflet lists as bowel obstruction (Wegovy leaflet)

For bloating that is severe, frequent or does not go away, the NHS says to see a GP (NHS bloating page). If the bloating comes with constipation, start with the steps in Mounjaro constipation relief.