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Zepbound (Tirzepatide) and Diarrhea: When to Call Your Doctor

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Published Updated Last reviewed
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At a glance

  • Diarrhea rate / 19% (5 mg), 21% (10 mg), 23% (15 mg) vs 8% placebo [1]
  • Any GI side effect / 56% on every Zepbound dose vs 30% placebo [1]
  • Severe GI reactions / 1.7% (5 mg), 2.5% (10 mg), 3.1% (15 mg) vs 1% placebo [1]
  • Stopped Zepbound for a GI reaction / 1.9%, 3.3%, 4.3% vs 0.5% placebo [1]
  • Most likely timing / during dose escalation; events decreased over time [1]
  • Kidney risk / acute kidney injury from volume depletion, mostly after GI reactions such as diarrhea [1]
  • Gallbladder / cholecystitis 0.7% vs 0.2%; cholelithiasis 1.1% vs 1% [1]
  • Pancreatitis / label says discontinue Zepbound if it is suspected [1]

How common is diarrhea on Zepbound?

Zepbound's diarrhea figures come from a pool of two placebo-controlled weight-management trials, SURMOUNT-1 and SURMOUNT-2, covering 958 people on placebo and 630, 948 and 941 people on 5, 10 and 15 mg, treated for up to 72 weeks [1]. Diarrhea — which the label counts together with frequent bowel movements — was reported by 19%, 21% and 23% of patients on 5, 10 and 15 mg respectively, against 8% on placebo [1].

At least one gastrointestinal adverse reaction occurred in 56% of patients on every Zepbound dose, versus 30% on placebo [1].

How severe does it get?

Severe gastrointestinal reactions were much less common than GI reactions overall, but they did occur: 1.7% of patients on 5 mg, 2.5% on 10 mg and 3.1% on 15 mg, versus 1% on placebo [1].

Permanent discontinuation for a GI adverse reaction occurred in 1.9%, 3.3% and 4.3% of patients on 5, 10 and 15 mg respectively, versus 0.5% on placebo; discontinuation for any adverse reaction was 4.8%, 6.3% and 6.7% versus 3.4% [1]. The label also states that Zepbound is not recommended in patients with severe gastroparesis [1].

What the label says to watch for

Dehydration and kidney injury. The label describes postmarketing reports of acute kidney injury, in some cases requiring hemodialysis, in patients treated with GLP-1 receptor agonists or Zepbound, and states that the majority of reported events occurred in patients who had gastrointestinal adverse reactions leading to dehydration such as nausea, vomiting or diarrhea [1]. The label instructs monitoring of renal function in patients reporting reactions that could lead to volume depletion, especially during dose initiation and escalation [1]. Zepbound needs no dose adjustment for renal or hepatic impairment [1].

Gallbladder disease. In the pooled weight trials, cholelithiasis was reported in 1.1% of Zepbound-treated patients versus 1% on placebo, cholecystitis in 0.7% versus 0.2%, and cholecystectomy in 0.2% versus none [1]. The label says acute gallbladder events were associated with weight reduction, and that if cholecystitis is suspected, gallbladder studies and clinical follow-up are indicated [1].

Pancreatitis. Acute pancreatitis, including fatal and non-fatal hemorrhagic or necrotizing cases, has been observed in patients treated with GLP-1 receptor agonists or Zepbound [1]. The label describes the presentation as persistent or severe abdominal pain, sometimes radiating to the back, which may or may not be accompanied by nausea or vomiting, and says Zepbound should be discontinued if pancreatitis is suspected [1]. In the pooled weight trials, 0.2% of Zepbound-treated patients had adjudication-confirmed acute pancreatitis, the same rate as placebo [1].

Does the dose change the risk?

Diarrhea rates rose with dose, from 19% at 5 mg to 23% at 15 mg [1]. The label's titration schedule is built around tolerability: 2.5 mg once weekly for 4 weeks as an initiation dose that is not approved as a maintenance dose, then 5 mg, with further 2.5 mg increments only after at least 4 weeks on the current dose, following a schedule intended "to reduce the risk of gastrointestinal adverse reactions" [1]. If a maintenance dose is not tolerated, the label says to consider a lower maintenance dose [1].

Does it improve over time?

The label states that the majority of nausea, vomiting and/or diarrhea events occurred during dose escalation and decreased over time [1].

What about other medicines you take?

Zepbound delays gastric emptying and can affect absorption of oral medicines [1]. The label advises caution with oral medicines and monitoring of drugs that depend on threshold concentrations for efficacy and those with a narrow therapeutic index, naming warfarin as an example [1].

If you use compounded tirzepatide

Those figures come from trials of Zepbound. Compounded tirzepatide is not FDA approved and is not reviewed for safety, effectiveness or quality before marketing; as of 2026-05-31, FDA had received more than 730 adverse event reports for compounded tirzepatide [2].

Frequently asked questions

How long does diarrhea from Zepbound last?
The label says the majority of nausea, vomiting and diarrhea events occurred during dose escalation and decreased over time; it gives no duration for an individual case [1].
Which symptoms does the label flag as serious?
Persistent or severe abdominal pain, especially pain that spreads to the back, with or without nausea or vomiting, is how the label describes pancreatitis, and it says Zepbound should be discontinued if pancreatitis is suspected [1]. Dehydration from vomiting or diarrhea is the label's kidney-injury scenario, and gallbladder studies and clinical follow-up are indicated if cholecystitis is suspected [1].
Does Zepbound cause more diarrhea than Mounjaro?
They cannot be ranked from these figures. The label says adverse reaction rates from one drug's trials cannot be directly compared with another drug's, and Zepbound's 19% to 23% come from trials in adults with obesity or overweight [1].
How often does diarrhea lead to stopping Zepbound?
The label reports stopping for gastrointestinal reactions as a group, not for diarrhea alone: these led to discontinuation in 1.9% of patients on 5 mg, 3.3% on 10 mg and 4.3% on 15 mg, versus 0.5% on placebo [1].

References

  1. U.S. National Library of Medicine, DailyMed. Zepbound injection (tirzepatide) prescribing information. Zepbound injection (tirzepatide) label
  2. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss | FDA. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss | FDA
Evidence overview for Zepbound (Tirzepatide) and Diarrhea: When to Call Your Doctor