Wegovy (Semaglutide 2.4 mg) Sulfur Burps: When to Call the Doctor

What the label lists for belching

Eructation (belching) appears in the Wegovy label's table of adverse reactions that occurred in at least 2% of adults and more often than on placebo: 7% on semaglutide 2.4 mg weekly versus under 1% on placebo, pooled from three placebo-controlled trials that treated 2,116 adults with Wegovy and 1,261 with placebo for up to 68 weeks [1]. It also appears in the label's list of most common adverse reactions, meaning 5% or more [1]. In the adolescent trial, eructation was reported by 4% of patients on Wegovy and 0% on placebo [1].

Other gut effects were more common than belching: nausea 44% vs 16%, diarrhea 30% vs 16%, vomiting 24% vs 6% and constipation 24% vs 11% in the same adult trials [1].

Symptoms the label flags

Persistent or severe abdominal pain. The label tells prescribers to observe for acute pancreatitis, which may include persistent or severe abdominal pain, sometimes radiating to the back, and which may or may not be accompanied by nausea or vomiting. It says Wegovy should be discontinued if pancreatitis is suspected [1]. Confirmed acute pancreatitis occurred in 4 Wegovy-treated adults (0.2 cases per 100 patient-years) versus 1 on placebo [1].

Gallbladder disease. The label reports more gallbladder disease on Wegovy: cholelithiasis in 1.6% vs 0.7% of adults and cholecystitis in 0.6% vs 0.2%, and says that if gallstones are suspected, gallbladder studies and clinical follow-up are indicated [1].

Severe gastrointestinal reactions. The label's warning covers 4.1% of Wegovy-treated adults versus 0.9% on placebo, says Wegovy is not recommended in patients with severe gastroparesis, and lists postmarketing reports of ileus, intestinal obstruction and severe constipation with fecal impaction [1].

Fluid loss and kidney injury. Acute kidney injury from volume depletion was reported at 0.4 vs 0.2 cases per 100 patient-years (7 vs 4 adults), more often in people with existing kidney problems and during dose increases, and often after gastrointestinal fluid loss. The label says to monitor renal function in patients reporting adverse reactions that could lead to volume depletion [1].

Serious allergic reactions. The label reports anaphylaxis and angioedema, and says to discontinue Wegovy and promptly seek medical advice if a hypersensitivity reaction is suspected [1].

Other symptoms the label names. Gastroesophageal reflux disease was reported in 5% vs 3% on placebo [1]. The boxed warning on thyroid C-cell tumors tells prescribers to counsel patients about a mass in the neck, trouble swallowing, shortness of breath and persistent hoarseness [1].

Does a lower dose, or a slower increase, change the burping?

The label gives 7% for 2.4 mg, and we found no eructation rate for 1.7 mg or 7.2 mg. Two label instructions do bear on tolerability. Doses increase every 4 weeks, and the label says that if a dose is not tolerated, consider delaying the escalation by 4 weeks [1]. For weight reduction the recommended maintenance dose is 2.4 mg weekly, with 1.7 mg as an alternative chosen on treatment response and tolerability; adults who tolerate 2.4 mg for at least 4 weeks and need more weight loss may increase to a maximum of 7.2 mg weekly [1].

Among adults who stopped Wegovy for any adverse reaction, the rate was 6.8% vs 3.2% on placebo; the leading reasons were nausea (1.8% vs 0.2%), vomiting (1.2% vs 0%) and diarrhea (0.7% vs 0.1%) [1]. Belching is not among the listed reasons for stopping.

Bismuth subsalicylate and hydrogen sulfide

Bismuth subsalicylate binds hydrogen sulfide, the gas behind a rotten-egg smell. In a 1998 study in Gastroenterology, 10 healthy volunteers took 524 mg four times a day for 3 to 7 days, and hydrogen sulfide release from their stool samples fell by more than 95% [2]. The study did not test burps or semaglutide. We found no study that tracked how long belching lasts on Wegovy, or that tested a low-sulfur diet or any over-the-counter remedy for belching during semaglutide treatment.