Constipation is one of Zepbound’s most common side effects. In the two main weight-loss trials, 11% to 17% of people on Zepbound reported it, depending on dose, against 5% on placebo [1]. Like nausea and diarrhea, it comes from a drug that slows your stomach down. Most of these effects eased with time, but a small share were severe, and knowing the warning signs matters more than any tip.
Constipation is common, and it was highest at the lowest dose
In the weight-loss trials, constipation was reported by 17% of people on 5 mg, 14% on 10 mg and 11% on 15 mg, against 5% on placebo [1]. The label counts “feces hard” under constipation. One detail stands out: the rate was highest at 5 mg, not 15 mg. The label doesn’t explain why.
Zepbound slows your stomach, which is why your gut changes
Zepbound slows how fast your stomach empties. That’s part of why you feel full sooner, and it’s also why digestion changes. The label says tirzepatide “delays gastric emptying,” and that the delay is largest after the first dose and shrinks over time [1]. How the drug works is explained on the Zepbound page.
Nausea and diarrhea are even more common than constipation
Nausea and diarrhea each affected roughly one in four people on Zepbound in the trials [1]. Vomiting was less common, at 8% to 13%. The label’s diarrhea figure includes “frequent bowel movements.”
| Side effect | Placebo | 5 mg | 10 mg | 15 mg |
|---|---|---|---|---|
| Nausea | 8% | 25% | 29% | 28% |
| Diarrhea | 8% | 19% | 21% | 23% |
| Vomiting | 2% | 8% | 11% | 13% |
| Constipation | 5% | 17% | 14% | 11% |
| Abdominal pain | 5% | 9% | 9% | 10% |
| Indigestion (dyspepsia) | 4% | 9% | 9% | 10% |
| Burping (eructation) | 1% | 4% | 5% | 5% |
| Acid reflux (GERD) | 2% | 4% | 4% | 5% |
| Gas (flatulence) | 2% | 3% | 3% | 4% |
| Bloating (abdominal distension) | 2% | 3% | 3% | 4% |
Studies 1 and 2, up to 72 weeks; placebo N=958, 5 mg N=630, 10 mg N=948, 15 mg N=941. Constipation includes “feces hard”; diarrhea includes “frequent bowel movements” [1].
Heartburn, burping, bloating and gas are less common
Reflux, burping, bloating and gas were each reported by about 3% to 10% of people on Zepbound, a few points above placebo [1]. Indigestion was the most common of the group, at 9% to 10%.
People often ask about “sulfur burps.” The label doesn’t use that term. Its word for burping is eructation, reported by 4% to 5% of people on Zepbound against 1% on placebo, and it doesn’t describe the smell.
Most stomach side effects ease after the dose stops rising
The label says “the majority of nausea, vomiting, and/or diarrhea events occurred during dose escalation and decreased over time” [1]. Each dose increase can bring them back for a while, so a rough stretch after a step up isn’t unusual. The dose range is covered in Zepbound dosage.
Tirzepatide stays in the body a long time. Its elimination half-life is about 5 to 6 days [1], which is why a weekly dose works and why side effects don’t switch off overnight. Claims that nausea lasts a set number of days aren’t backed by the label, so treat them with caution. The full list of side effects and how long they last is on Zepbound side effects.
Some stomach symptoms mean you should call right away
A small share of people have severe stomach reactions: 1.7% on 5 mg, 2.5% on 10 mg and 3.1% on 15 mg, against 1% on placebo [1]. The label says Zepbound “is not recommended in patients with severe gastroparesis.” The sleep apnea trials showed similar rates. After approval, reports came in of “ileus, intestinal obstruction, severe constipation including fecal impaction,” along with pancreatitis.
Fluid loss is the other risk. The label says most kidney-injury reports “occurred in patients who experienced gastrointestinal adverse reactions leading to dehydration such as nausea, vomiting, or diarrhea” [1].
| Symptom | Why it matters |
|---|---|
| Severe belly pain that won’t go away, sometimes reaching your back, with or without vomiting | Possible pancreatitis (label §5.5) |
| Vomiting or diarrhea that won’t stop, dizziness, or peeing much less than usual | Dehydration, which can lead to kidney injury (label §5.3) |
| Can’t pass stool or gas, with a swollen or painful belly | Possible blockage; reported after approval (label §6.2) |
| Pain in your upper stomach, fever, yellowing of skin or eyes, or clay-colored stools | Possible gallbladder problem (Medication Guide) |
Symptoms drawn from the Zepbound prescribing information and Medication Guide [1]. In an emergency, call 911.
Gallbladder problems are covered with the other serious side effects on Zepbound side effects.
The slow dose start is the built-in fix; the rest is up to your prescriber
Every Zepbound patient begins on 2.5 mg, per the label, a dose for getting started rather than staying on, and the dose rises gradually from there [1]. That gradual start is the label’s built-in way to soften stomach side effects. If a maintenance dose is hard to tolerate, the label tells prescribers to “consider a lower maintenance dosage.”
The Medication Guide adds one thing you can do: “It is important for you to drink fluids to help reduce your chance of dehydration. Tell your healthcare provider right away if you have nausea, vomiting, or diarrhea that does not go away” [1]. For constipation remedies, food changes or anti-nausea medicine, ask your prescriber what suits you. Don’t start or skip doses on your own.
- Tell your prescriber if constipation keeps going, gets worse, or comes with pain or swelling.
- Mention every other medicine you take; Zepbound’s slower digestion can affect pills taken by mouth.
- Ask before using any over-the-counter remedy, so it fits with your other treatment.
Few people stopped Zepbound because of stomach side effects
Stomach side effects led 1.9% of people on 5 mg, 3.3% on 10 mg and 4.3% on 15 mg to stop treatment, against 0.5% on placebo [1]. The label says most people who stopped for side effects did so in the first few months, because of stomach effects.
If you take compounded tirzepatide rather than Zepbound, these label numbers are the closest guide there is, but the product itself carries extra risks covered in is compounded tirzepatide safe and on the compounded tirzepatide page. What Zepbound costs is broken down in Zepbound cost. If you’re weighing Zepbound against Wegovy, the semaglutide side of the stomach question is on Wegovy nausea, where nausea was reported by 44% of people on the 2.4 mg dose [2].
Weighing programs on price? The brand Wegovy and Zepbound self-pay programs lineup sets 21 of them side by side, each with its true monthly cost.