Sources last read
Zepbound side effects, as its own label reports them
Nausea tops Zepbound’s label table at 25, 29 and 28 in every 100 people on 5, 10 and 15 mg, against 8 on placebo.
Source: Read from the Zepbound label, revision 04/2026
What matters first
Medically reviewed by Jennifer Montecillo, MD · non-practicing medical reviewerReviewed 2026-08-12every number here is sourced
The two placebo-controlled weight trials, dose by dose
Read the placebo column first. Nearly everything below happens to some people on a dummy injection too, and the gap between the columns is the part the drug is answerable for.
Trial armsPlacebo: n = 958Zepbound 5 mg: n = 630Zepbound 10 mg: n = 948Zepbound 15 mg: n = 941
| Side effect | Placebo | Zepbound 5 mg | Zepbound 10 mg | Zepbound 15 mg |
|---|---|---|---|---|
| Nausea | 8% | 25% | 29% | 28% |
| DiarrheaGroups diarrhea and frequent bowel movements | 8% | 19% | 21% | 23% |
| Vomiting | 2% | 8% | 11% | 13% |
| ConstipationGroups constipation and hard stools | 5% | 17% | 14% | 11% |
| Belly pain | 5% | 9% | 9% | 10% |
| Indigestion | 4% | 9% | 9% | 10% |
| Reactions where you injectGroups bruising, redness, itching, pain and rash at the injection site | 2% | 6% | 8% | 8% |
| Tiredness | 3% | 5% | 6% | 7% |
| Allergic reactions | 3% | 5% | 5% | 5% |
| Burping | 1% | 4% | 5% | 5% |
| Hair loss | 1% | 5% | 4% | 5% |
| Acid reflux | 2% | 4% | 4% | 5% |
| Wind | 2% | 3% | 3% | 4% |
| Bloating | 2% | 3% | 3% | 4% |
| Dizziness | 2% | 4% | 5% | 4% |
| Low blood pressureGroups low blood pressure and blood pressure drops on standing | 0% | 1% | 1% | 2% |
The boxed warning: thyroid tumors in rodents
Zepbound opens with a boxed warning about thyroid C-cell tumors found in rats. It is not known whether tirzepatide does the same in people. The label rules the drug out where medullary thyroid cancer runs in the family, and where someone has the inherited condition MEN 2.
What does the label tell prescribers to watch for?
These sit above the table in the label, in the section reserved for the problems that are rare but matter most.
| Warning | What this label says about it |
|---|---|
| Pancreatitis | The label says to stop if it is suspected. |
| Gallbladder disease | Reported more often than on placebo in the weight trials. |
| Severe stomach and gut problems | Reported by 1.7, 2.5 and 3.1 in every 100 people on 5, 10 and 15 mg, against 1 on placebo. This is one of the few places the label shows a clean rise with the dose. |
| Low blood sugar | Mainly where Zepbound is taken alongside insulin or a sulfonylurea. |
| Kidney injury | Usually following fluid loss. |
| Serious allergic reactions | The label lists these separately from the milder ones in the table. |
| Diabetic eye disease | Relevant to the quarter of the trial population who had type 2 diabetes. |
| Breathing in stomach contents under anesthetic | The label tells anesthetists not to assume the stomach is empty. |
What have people actually reported about Zepbound?
70,141 reports naming Zepbound have reached the FDA’s public database. A report is not proof the drug caused anything, and there is no way to know how many people took it.
| Most reported | Reports | Share of Zepbound reports |
|---|---|---|
| Wrong dose given | 12,768 reports | 18% of Zepbound reports |
| Nausea | 7,913 reports | 11% of Zepbound reports |
| Injection site pain | 4,792 reports | 6.8% of Zepbound reports |
| Drug ineffective | 4,602 reports | 6.6% of Zepbound reports |
| Extra dose given | 4,527 reports | 6.5% of Zepbound reports |
| Diarrhea | 4,360 reports | 6.2% of Zepbound reports |
| Vomiting | 3,496 reports | 5.0% of Zepbound reports |
| Constipation | 3,026 reports | 4.3% of Zepbound reports |
| Accidental underdose | 2,612 reports | 3.7% of Zepbound reports |
| Fatigue | 2,444 reports | 3.5% of Zepbound reports |
The single most reported item for Zepbound is not a side effect at all. It is a dosing error — the wrong dose going in.
Nausea sits second. Below it are more dosing entries: an extra dose given, and an accidental underdose. Zepbound is drawn from a vial with a syringe far more often than the semaglutide pens are, and the report pile shows what that costs.
4Interpret the page
The side effects do not simply rise with the dose
Nausea peaks at 10 mg, not at 15. Constipation runs the other way entirely: 17 in 100 at 5 mg, falling to 11 at 15 mg.
In this table, only vomiting and diarrhea climb cleanly with each step. That matters when you are working out whether a dose rise is what changed how you feel. For most of these rows, the label’s own numbers say it need not be.
The one effect that does rise steadily is stopping altogether: 4.8, then 6.3, then 6.7 in every 100 people.
The sleep apnea trials did not produce a separate table
467 adults with moderate to severe sleep apnea and obesity took part in two more trials, one in people using a breathing machine and one in people who were not.
The label reports no separate percentages for them. It says what was seen on 10 mg and 15 mg looked like the weight trials above. That is the honest state of the published data, and it is why this page has one table rather than two.
Why do Zepbound and Mounjaro report different numbers for the same drug?
Both are tirzepatide. The percentages differ because the trials behind them differ, not because one product is gentler than the other.
Each label opens its table with the same warning: rates from one drug’s trials cannot be set against another’s. That holds here even though the drug substance is identical. The two sets of trials enrolled different people. They ran to different doses. And they used different cut-offs for what got printed at all.
Where to read next
Two pages carry the parts this one leaves out.
- The Zepbound dose schedule has the step pattern these percentages are attached to.
- Side effects of tirzepatide itself covers the drug across every product built on it.
Questions readers ask
Is Zepbound safer than Ozempic?
What not to do when taking Zepbound?
Are there any long-term side effects from Zepbound?
How much weight can you lose on Zepbound in 3 months?
- ZEPBOUND (tirzepatide) injection — DailyMed SPL, sections 5 and 6.1retrieved 2026-08-12FDA label