This is one label's record. The class-wide picture — how Zepbound's figures sit next to Wegovy's, and why the discontinuation rates tell a different story from the nausea rates — is on our GLP-1 side effects page. This page reads the ZEPBOUND prescribing information (Eli Lilly, NDA 217806, SPL effective 28 August 2026) end to end, as published through openFDA and read on 23 September 2026, and reports what it counts.
Nothing here tells anyone what to do about a symptom. Where the label tells patients to do something, that is reported as what the label says, and the decision sits with the prescriber.
The counted reactions, with placebo subtracted
The label's Table 1 pools two placebo-controlled weight trials: Study 1 (SURMOUNT-1, adults without diabetes) and Study 2 (SURMOUNT-2, adults with type 2 diabetes). In total 2,519 people received Zepbound for up to 72 weeks. The last column is our arithmetic, not the label's: the 15 mg rate minus the placebo rate, which is the share of people for whom the drug, rather than ordinary life, plausibly explains the report.
| Reaction | Placebo | 5 mg | 10 mg | 15 mg | Excess at 15 mg |
|---|---|---|---|---|---|
| Nausea | 8% | 25% | 29% | 28% | +20 |
| Diarrhoea | 8% | 19% | 21% | 23% | +15 |
| Vomiting | 2% | 8% | 11% | 13% | +11 |
| Constipation | 5% | 17% | 14% | 11% | +6 |
| Abdominal pain | 5% | 9% | 9% | 10% | +5 |
| Indigestion (dyspepsia) | 4% | 9% | 9% | 10% | +6 |
| Injection-site reactions | 2% | 6% | 8% | 8% | +6 |
| Fatigue | 3% | 5% | 6% | 7% | +4 |
| Hypersensitivity reactions | 3% | 5% | 5% | 5% | +2 |
| Burping (eructation) | 1% | 4% | 5% | 5% | +4 |
| Hair loss | 1% | 5% | 4% | 5% | +4 |
| Reflux | 2% | 4% | 4% | 5% | +3 |
| Flatulence | 2% | 3% | 3% | 4% | +2 |
| Abdominal distension | 2% | 3% | 3% | 4% | +2 |
| Dizziness | 2% | 4% | 5% | 4% | +2 |
| Low blood pressure | 0% | 1% | 1% | 2% | +2 |
Placebo is not zero, and for several rows it is most of the number. Eight in every hundred people injecting nothing reported nausea. A reader trying to decide whether a symptom is the drug is working against that background.
The number that does not move, and the one that does
The label adds a figure the table cannot show: the share reporting any gastrointestinal reaction was 56% on 5 mg, 56% on 10 mg and 56% on 15 mg, against 30% on placebo. Tripling the dose did not change how many people had a stomach complaint at all.
What did change was how many stopped because of one: 1.9% at 5 mg, 3.3% at 10 mg, 4.3% at 15 mg, against 0.5% on placebo. The count of people affected is flat; the count of people affected badly enough to quit more than doubles. On this label the dose effect is carried by severity, not by frequency — which is why a single "nausea percentage" is the least informative number on the page.
Overall, 4.8%, 6.3% and 6.7% of patients on the three doses permanently stopped for any adverse reaction, against 3.4% on placebo. The label says most who stopped did so "during the first few months of treatment due to gastrointestinal adverse reactions", and that most nausea, vomiting and diarrhoea "occurred during dose escalation and decreased over time". It gives no duration for an individual episode.
One more population, a less flattering one. Study 3 (SURMOUNT-3) started people on an intensive lifestyle programme before they received anything. After that lead-in, 10% of Zepbound patients and 2% on placebo stopped because of adverse reactions — a higher rate than in the pooled trials. The label reports it and does not comment. People who had already lost weight on diet alone before starting were, in that trial, more likely to stop than the pooled figures suggest.
The one reaction that falls with dose, constipation, is discussed on our GLP-1 side effects page; the label offers no explanation for it and neither will we.
The antibody effect
Section 6 reports something the headline table flattens. Among Zepbound patients in the pooled trials:
| Developed anti-tirzepatide antibodies | Did not | |
|---|---|---|
| Injection-site reactions | 11.3% | 1% |
| Hypersensitivity reactions | 6.2% | 3% |
Injection-site reactions were about eleven times as common in people whose immune system made antibodies to the drug. Most hypersensitivity reactions in the trials were skin reactions such as rash and itching; immediate reactions within a day of an injection occurred in 2.1% on Zepbound against 0.4% on placebo. The label does not say what share of patients develop antibodies in this section, and does not suggest any action based on antibody status — nobody is routinely tested for them.
Blood sugar, blood pressure, heart rate
- Low blood sugar. In the diabetes trial (Study 2), a reading below 54 mg/dL was reported in 4.2% on Zepbound against 1.3% on placebo. In Study 1, which excluded diabetes and did not systematically capture it, 0.3% against none. The label's warning is chiefly about use alongside insulin or a sulfonylurea.
- Low blood pressure. 1.6% against 0.1%, and 2.2% in people already taking blood-pressure medicines against 1.2% in those who were not. Some episodes were linked to stomach upset and dehydration.
- Heart rate. A mean increase of 1 to 3 beats per minute, against none on placebo.
- Kidney injury. 0.5% against 0.2%. The postmarketing section adds acute kidney failure or worsening chronic kidney failure, "sometimes requiring hemodialysis".
The contraception warning
Of everything in this label, this is the sentence most likely to matter to a reader and least likely to have been mentioned to them. Section 7 advises patients using oral hormonal contraceptives to switch to a non-oral method, or add a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase. The reason given is delayed stomach emptying, which can reduce how much of an oral medicine is absorbed. The label states that hormonal contraceptives not taken by mouth should not be affected.
Two things follow from the label's own wording. The window reopens at every dose step, not only at the start. And because the Zepbound label's section 8 carries its own pregnancy guidance, this is not a footnote; our pregnancy page sets out what the labels say about conception and discontinuation. Whether any of it applies to a particular person's contraception is a question for their prescriber or pharmacist.
The sleep-apnoea population
Zepbound is also approved for moderate to severe obstructive sleep apnoea in adults with obesity, based on Studies 5 and 6 (SURMOUNT-OSA; 467 adults). The label says the side effects in those trials were similar to the weight trials, with one figure that is not: adjudication-confirmed acute pancreatitis at 0.84 patients per 100 years of exposure on Zepbound and 0 on placebo. In the weight trials the same figure was 0.14 against 0.15. The OSA trials are small, and a rate built on a few cases moves a long way; the label reports it without interpretation, and so do we. The full pancreatitis record, across the class, is on our pancreatitis page.
The warnings, and where each is covered
The label's Warnings and Precautions list nine items plus a boxed warning. We do not restate the ones that already have their own page.
- Thyroid C-cell tumours (boxed warning, from rat studies) — thyroid cancer page.
- Severe gastrointestinal reactions, and the label's statement that Zepbound is not recommended in severe gastroparesis.
- Acute kidney injury from dehydration — above.
- Acute gallbladder disease — cholelithiasis 1.1% against 1%, cholecystitis 0.7% against 0.2%; gallbladder page.
- Acute pancreatitis — pancreatitis page.
- Hypersensitivity, including anaphylaxis and angioedema after approval.
- Hypoglycaemia — above.
- Diabetic retinopathy complications in people with type 2 diabetes.
- Pulmonary aspiration during anaesthesia or deep sedation — the label tells patients to inform their healthcare providers of planned procedures; our surgery page covers the guidance.
- Never share a KwikPen, even with a new needle.
Hair loss (4–5% against 1%, and 7.1% of women against 0.5% of men) is on our hair loss page. How these rates change as the dose climbs, across the class, is on our dose and side effects page.
What this page cannot tell you
- What any one person will experience. These are group rates from trials with lifestyle support and regular visits.
- How Zepbound compares with another drug. The label warns that rates from one programme cannot be compared with another's; the Mounjaro comparison shows how far that goes even for the same molecule.
- How rare harms behave outside trials. The postmarketing list — pancreatitis sometimes resulting in death, bowel obstruction, severe constipation, anaphylaxis, kidney failure — is, in the label's words, from "a population of uncertain size", so it carries no rate.
Anyone experiencing a side effect, or weighing one, should take it to the person who prescribed the medicine. Our tirzepatide review covers the trial record beyond safety.
Sources
- ZEPBOUND (tirzepatide) injection, prescribing information, Eli Lilly and Company, NDA 217806, SPL effective 2026-08-28 — read 2026-09-23 via openFDA: boxed warning, sections 1, 5, 6.1, 6.2 and 7.
- SURMOUNT-1 NCT04184622 and SURMOUNT-2 NCT04657003, as pooled in the label's Table 1.