Does Wegovy Cause Constipation?

How common is constipation on Wegovy?

The Wegovy label pooled three placebo-controlled trials of the 2.4 mg weekly injection in adults with obesity or overweight, running up to 68 weeks, with 2,116 people on Wegovy and 1,261 on placebo [1]. In that table, constipation was reported by 24% of people on Wegovy and 11% on placebo [1].

That placed constipation level with vomiting (24% vs 6%) and just behind nausea (44% vs 16%) and diarrhea (30% vs 16%). Abdominal pain was reported by 20% vs 10%, and any gastrointestinal reaction by 73% vs 47% [1].

Constipation was not one of the leading reasons people stopped treatment. Overall, 6.8% of people on Wegovy and 3.2% on placebo discontinued for adverse reactions, and the label names nausea (1.8% vs 0.2%), vomiting (1.2% vs 0%) and diarrhea (0.7% vs 0.1%) as the most common reasons for stopping [1].

Does a higher dose mean more constipation?

Not clearly. In two 72-week trials of the 7.2 mg weekly dose, with 1,311 people on 7.2 mg, 304 on 2.4 mg and 303 on placebo, constipation was reported by 20%, 19% and 8% respectively [1]. That is a small difference between the two active doses.

Other reactions did climb with dose over the same comparison. Dysesthesia, an altered skin sensation such as burning or pain from touch, was reported by 22% on 7.2 mg, 6% on 2.4 mg and 0% on placebo, and the label notes that 18% of those affected on 7.2 mg had not recovered by the end of the trial [1]. Constipation did not follow that pattern.

Do the Wegovy tablets cause it too?

The label's safety data for the 25 mg once-daily tablets come from a single 64-week trial in adults with obesity or overweight and no diabetes, and the label states that the types and frequencies of reactions were similar to the injection table [1]. In that trial, severe gastrointestinal reactions were reported by 2% on the tablets versus 0% on placebo, and 6.9% versus 5.9% discontinued for adverse reactions, with gastrointestinal reasons accounting for 3.4% versus 2% [1].

What the label says about why it happens

Semaglutide delays gastric emptying [1]. The label reports constipation as an adverse reaction with observed rates and does not state the specific reason it occurs [1].

When constipation is more than a common side effect

The label separates ordinary constipation from severe gastrointestinal reactions. Severe GI adverse reactions occurred in 4.1% of people on Wegovy injection versus 0.9% on placebo, and in 2% versus 0% for the tablets [1]. Those figures cover severe gastrointestinal reactions of any kind, not severe constipation specifically. After approval, the label lists ileus, intestinal obstruction and severe constipation including fecal impaction as reported events, and states that a frequency cannot be estimated from voluntary reports [1].

The labels also say semaglutide is not recommended in patients with severe gastroparesis, and they do not state that the drug causes gastroparesis [1].

Abdominal pain has a separate warning. The label describes acute pancreatitis as persistent or severe abdominal pain, sometimes radiating to the back, which may or may not come with nausea or vomiting, and says to discontinue Wegovy and start appropriate management if pancreatitis is suspected [1].

Fluid loss and the kidney warning

Vomiting and diarrhea are also listed Wegovy reactions, reported by 24% versus 6% and 30% versus 16% on Wegovy and placebo in the same pooled trials [1]. The label warns about acute kidney injury due to volume depletion, reported at 0.4 versus 0.2 cases per 100 patient-years (7 versus 4 adults), occurring more often in people with existing kidney impairment and during dose titration, and often after gastrointestinal fluid loss [1].