Wegovy (Semaglutide 2.4 mg) Sulfur Burps: The Biology of Why It Happens and How to Manage Them

Does Wegovy cause burping?

Yes. Eructation appears in the Wegovy adverse reaction table for the 2.4 mg weekly injection: 7% of 2,116 adults reported it, against fewer than 1% of 1,261 people on placebo, in three pooled trials lasting up to 68 weeks [1]. It is also on the label's list of the most common adverse reactions, meaning those seen in 5% or more of patients [1].

Where would a rotten-egg smell come from?

A rotten-egg odor is often attributed to hydrogen sulfide. Wegovy delays stomach emptying, but whether that delay causes sulfur-smelling burps has not been established, and we found no study that measured hydrogen sulfide, gas volume or odor in people taking Wegovy [1].

How burping compares with the other gut effects

Burping is among the less frequent of the label's common reactions for 2.4 mg. Nausea was reported by 44% vs 16% on placebo, diarrhea 30% vs 16%, vomiting 24% vs 6%, constipation 24% vs 11%, abdominal pain 20% vs 10%, dyspepsia 9% vs 3%, abdominal distension 7% vs 5%, flatulence 6% vs 4% and reflux 5% vs 3% [1]. Any GI reaction occurred in 73% vs 47% [1].

Overall, 6.8% on Wegovy and 3.2% on placebo stopped for adverse reactions, and the reasons the label lists are nausea (1.8% vs 0.2%), vomiting (1.2% vs 0%) and diarrhea (0.7% vs 0.1%); burping is not among them [1].

What the label does advise

The label's own lever on gut side effects is the titration schedule: 0.25 mg for weeks 1 to 4, 0.5 mg for weeks 5 to 8, 1 mg for weeks 9 to 12, 1.7 mg for weeks 13 to 16, then maintenance from week 17, with each step four weeks apart to reduce the risk of gastrointestinal adverse reactions [1]. If a dose is not tolerated, the label says to consider delaying escalation by four weeks [1]. The adult maintenance dose can be 2.4 mg or 1.7 mg, and the label says to consider treatment response and tolerability when selecting it [1].

That schedule is aimed at gastrointestinal adverse reactions as a group; the label gives no separate instruction for burping [1].

When burping is not the whole picture

The label separates ordinary gut side effects from severe ones. Severe GI adverse reactions occurred in 4.1% on Wegovy versus 0.9% on placebo [1]. Wegovy is not recommended in patients with severe gastroparesis, and postmarketing reports include ileus, intestinal obstruction and severe constipation with fecal impaction [1].

The label also warns about acute pancreatitis, which may show up as persistent or severe abdominal pain sometimes radiating to the back, with or without nausea or vomiting, and says Wegovy should be discontinued if pancreatitis is suspected [1].