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Does a GLP-1 cause diarrhea?

Yes. Wegovy, Mounjaro and Zepbound list diarrhea as a side effect. Product labels report study rates; the separate FDA table counts voluntary reports. These are different kinds of evidence.

What the product trials found

These are separate trials, so their rates cannot rank the medicines.

Wegovy

The 2.4 mg weekly shot, in the weight trials

Wegovy: Diarrhea. Percent of people who reported it, by trial arm.
Dose / groupRate
Placebo1,261 people16%
2.4 mg2,116 people30%
Study group and source

2,116 adults with obesity or overweight took the 2.4 mg shot across three placebo-controlled trials. 1,261 took placebo. The average age was 48 and 71% were women.

Up to 68 weeks, then 7 weeks off the drug

Everything reported by 2 in 100 people or more, and more often than on placebo

Read the product label
All Wegovy side effects

Mounjaro

The two placebo-controlled diabetes trials in adults

Mounjaro: Diarrhea. Percent of people who reported it, by trial arm.
Dose / groupRate
Placebo235 people9%
5 mg237 people12%
10 mg240 people13%
15 mg241 people17%
Study group and source

718 adults with type 2 diabetes took Mounjaro across SURPASS-1 and SURPASS-5. The average age was 58 and people had had diabetes for about 9 years.

An average of 36.6 weeks on the drug

Everything reported by 5 in 100 people or more, and more often than on placebo. Low blood sugar is counted separately.

Read the product label
All Mounjaro side effects

Zepbound

The two placebo-controlled weight trials, dose by dose

Zepbound: Diarrhea. Percent of people who reported it, by trial arm.
Dose / groupRate
Placebo958 people8%
5 mg630 people19%
10 mg948 people21%
15 mg941 people23%

Groups diarrhea and frequent bowel movements

Study group and source

2,519 adults with obesity or overweight took Zepbound across two trials. The average age was 47 and the average BMI 37.4. A quarter also had type 2 diabetes.

Up to 72 weeks, then 4 weeks off the drug

Everything reported by 2 in 100 people or more, and more often than on placebo

Read the product label
All Zepbound side effects

Medically reviewed by Jennifer Montecillo, MD · non-practicing medical reviewer

Information checked 2026-09-07

How these findings apply

A report can describe a suspected reaction without proving what caused it. Report shares cannot show how common diarrhea is among all people taking a medicine.

Ozempic and Wegovy contain semaglutide; Mounjaro and Zepbound contain tirzepatide. Sharing an ingredient does not make their doses or trial reaction rates the same.

Compound summary coverage

Compounds that list it

7 of 42

Only in a combined category

1

No reaction list in this guide

16

Best available source

FDA label

Which compound summaries list diarrhea

The table checks the reaction entries in each compound summary. Some name diarrhea; others include it in a broader group or have no matching entry. A missing entry is not proof that the full label omits the reaction.

◆ Diarrhea across 42 compoundsguide or source for every row
Every compound covered on this site, showing whether it lists diarrhea and at what frequency its own cited source states.
CompoundHow it appearsFrequency reportedSource type
TirzepatideZepbound, MounjaroDiarrheaVery common (≥10%)FDA labelRead source
SemaglutideWegovy, Ozempic, RybelsusDiarrheaVery common (≥10%)FDA labelRead source
LiraglutideVictoza, SaxendaDiarrheaReported in Victoza trials (≥5%)FDA labelRead source
RetatrutideDiarrheaReported in trials (dose-dependent)Human trialRead source
CagrilintideStomach and gut events overall (nausea, constipation, diarrhea)counted inside a grouped figure, not on its ownReported in 41–63% across trial doses (vs 32% placebo)Human trialRead source
SurvodutideNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—Human trial
BPC-157No reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
TesamorelinEgrifta SV, Egrifta WRNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—FDA label
PT-141VyleesiNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—FDA label
CJC-1295Not listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
IpamorelinNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—Human trial
TB-500No reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
GHK-CuNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
SermorelinNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
MOTS-cNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
AOD-9604Not listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
NAD+Not listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
EpitalonNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
Kisspeptin-10No reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
DSIPNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
HexarelinNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
IGF-1 LR3No reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
PEG-MGFNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
LL-37Not listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
KPVNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
Thymosin alpha-1Not listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
SS-31ForzinityNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—FDA label
SemaxNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
SelankNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
Melanotan IINot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
MazdutideDiarrheaReported by 39.4% on 9 mg weekly (vs 6.5% on placebo)Human trialRead source
PinealonNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—limited human data
AHK-CuNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
VK2735Not listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—Human trial
ZenagamtideNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—Human trial
PemvidutideDiarrheaIn RECLAIM, the sponsor reported 20% with pemvidutide versus 10% with placeboHuman trialRead source
BrenipatideNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
EloralintideNot listed in this summaryThis short reaction list does not include the symptom. Check the full product label or study for more detail.—Human trial
EnicepatideNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
MacupatideNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
MariTideNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work
PetrelintideNo reaction list in this guideThis guide has no reaction entries. That does not establish that no human safety evidence exists.—no human dose shown to work

These tables summarize selected reaction entries. A missing entry does not mean the full label or all published studies omit it. A summary does not replace the full prescribing information. A pharmacist or clinician can review the complete label alongside the rest of a person’s medicines.

What people reported to the FDA

The first table summarizes labels and published trials. This table shows reports filed with the FDA after the medicines went on sale. Each percentage is the share of reports for that product that mention this symptom—not the share of patients who experienced it.

Each GLP-1 brand in the FDA snapshot, and what share of its reports names this symptom.
ProductShare of its own reportsAll reports
Ozempicsemaglutide9.0% of Ozempic reports66,161 reports
Rybelsussemaglutide7.9% of Rybelsus reports7,379 reports
Victozaliraglutide7.1% of Victoza reports44,086 reports
Trulicitydulaglutide6.9% of Trulicity reports88,332 reports
Mounjarotirzepatide6.3% of Mounjaro reports93,975 reports
Zepboundtirzepatide6.2% of Zepbound reports70,141 reports
Saxendaliraglutide5.5% of Saxenda reports10,040 reports
Wegovysemaglutide5.5% of Wegovy reports21,044 reports

A row reading “below” is not a zero. The snapshot keeps each product’s 25 most-reported terms, so a term missing from that list was either never reported or reported outside the stored list. The cutoff provides an upper bound, not an exact count. Read from FDA on 2026-08-17.

Reports are not rates and a report is not proof the drug did it. How to read this data, and the questions it answers on its own.

3Read deeperWhy it happens, when it appears, and what the evidence shows

Diarrhea and other bowel changes

The labels describe effects on stomach emptying and list several gut reactions. That does not fully explain why one person develops diarrhea.

A new bowel symptom can have other causes too. Its timing, other medicines and any signs of dehydration matter when a clinician assesses it.

Constipation is also reported

Constipation, Stomach and gut events overall (nausea, constipation, diarrhea) and Stomach and gut events overall (nausea, vomiting, constipation) is also listed for Tirzepatide (very common (≥10%)), Semaglutide (very common (≥10%)), Liraglutide (reported in Saxenda trials (≥5%)), Retatrutide (reported in trials), Cagrilintide (reported in 41–63% across trial doses (vs 32% placebo)), Survodutide (reported in 75% of survodutide recipients (vs 42% placebo)), VK2735 (treatment-related event in 37 of 175 participants in the phase 2 safety population) and Pemvidutide (in RECLAIM, the sponsor reported 26% with pemvidutide versus 6% with placebo). Each result links to its original source.

Both diarrhea and constipation appear in these product labels. Their rates can differ. A group’s reaction list does not predict which symptom one person will have.

When diarrhea was reported

Mounjaro and Zepbound label studies found that nausea, vomiting and diarrhea occurred mostly during dose increases and became less frequent over time. That does not establish a fixed duration for diarrhea.

The FDA snapshot here counts reports mentioning the term. It does not provide an episode-by-episode timeline, even though the wider reporting system can receive follow-up information.

What the evidence shows

Read each finding with the limits of the source that measured it.

What the evidence shows
The claimWhat the evidence shows
Diarrhea is a documented side effect.The product labels list it. The table also shows which compound summaries name it or include it within a broader group.
A report share is the chance I will get diarrhea.No. The denominator is reports, not everyone who used the medicine. Study rates and report shares must stay separate.
More reports mean one brand is less safe.Report counts alone cannot establish that. Use the product’s study findings and any relevant direct comparisons.
Diarrhea means the dose should change.Tolerability matters to dose decisions. A reaction table cannot decide what is right for an individual; the prescriber needs the symptom history.

When diarrhea needs medical attention

Persistent diarrhea can cause fluid loss. Seek prompt medical help if you cannot stay hydrated or have severe or lasting belly pain.

Acute pancreatitis

Urgent

Signs: Severe pain high in the abdomen that will not let up and may bore through to the back, often with nausea or vomiting that does not settle. People describe it as different from ordinary post-dose nausea, in that it does not come and go with meals.

The prescribing information lists this as a reaction that needs medical assessment. Call a clinician without waiting for the next appointment, or emergency services if the pain is severe.

Acute kidney injury from dehydration

Prompt

Signs: Vomiting or diarrhea bad enough that you cannot keep fluids down, passing much less urine than usual, dizziness when you stand up, or unusual weakness.

The label links the risk to dehydration, so ongoing fluid loss is worth reporting early. A clinician can check kidney function.

These warnings can help you recognize a concern. A clinician can assess your symptoms alongside your health history and other medicines.

EmergencySome symptoms should not wait for an appointment. Call emergency services (911 in the US) if they are severe, getting worse fast, or involve trouble breathing, chest pain, fainting or confusion.

Common questions

Is diarrhea listed on the Ozempic and Wegovy labels?

The semaglutide summary below is not a complete search of both product labels. Use each brand’s side-effect guide for its own label and study group.

Do not transfer a rate between Ozempic and Wegovy just because both contain semaglutide.

How long does it last?

The tables here do not measure how long each episode lasted. The pattern during dose increases is described above; it is not a personal timetable.

Why does the same drug cause both diarrhea and constipation?

Both reactions are listed. A label table records what happened in a study; it does not fully explain why one person developed one symptom rather than the other.

Does it mean the medicine is working?

Diarrhea does not measure treatment benefit. Do not use discomfort alone to judge progress or to decide on a dose change.

Why does the report-stream table have no dashed rows?

A numbered row means the stored FDA snapshot contains that term. A dash means the term was not in the stored list, not that nobody reported it.

Where a cutoff is shown, it is an upper bound based on the stored list, not an exact missing count. These are report counts, not rates of illness.

Want the full picture for one compound? Open its guide for uses, dosage information, side effects and serious warnings.

Every tirzepatide reaction, not only diarrhea

9 common and 6 serious tirzepatide reactions, in full past diarrhea.

The full semaglutide profile behind its diarrhea entry

Frequencies as the semaglutide source states them, read directly rather than via diarrhea.

Which pages list constipation, beyond the diarrhea question

Named constipation entries, grouped figures and absences kept distinct, apart from diarrhea.

The nausea question, alongside diarrhea

One reaction, nausea, read down every page instead of out of diarrhea alone.

Look up the medicines mentioned in the diarrhea guide

Explore approval status and published research related to diarrhea.

How long diarrhea lasts, and why nobody says

No source cited on this site states how long any of these reactions lasts, with diarrhea as one example

What else mazdutide lists besides diarrhea

No boxed warning applies to mazdutide, on the mazdutide page rather than on diarrhea.

The full pemvidutide profile behind its diarrhea entry

Frequencies as the pemvidutide source states them, read directly rather than via diarrhea.

Every cagrilintide reaction, not only diarrhea

4 common and 0 serious cagrilintide reactions, in full past diarrhea.

Every symptom in this section is listed on the symptom questions index.

13primary sources, each with the day we read it — open the documents used on this page