ProvaFacts on this page come from FDA labels and official sources, listed at the end. It's general information, not medical advice: your prescriber comes first.
In the FDA label, most Zepbound side effects get a little more common from 5 mg to 15 mg. Nausea went from 25% to 28% and vomiting from 8% to 13%. Constipation went the other way, and the label says most nausea, vomiting and diarrhea happened while the dose was going up, then eased over time.
Zepbound side effects at 5, 10 and 15 mg
These are the label's numbers from its two main weight loss trials, 72 weeks each. Every row is a side effect reported in at least 2% of people on Zepbound and more often than on placebo.
| 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% |
| Injection site reactions | 2% | 6% | 8% | 8% |
| Fatigue | 3% | 5% | 6% | 7% |
| Allergic (hypersensitivity) reactions | 3% | 5% | 5% | 5% |
| Burping (eructation) | 1% | 4% | 5% | 5% |
| Hair loss | 1% | 5% | 4% | 5% |
| Reflux (GERD) | 2% | 4% | 4% | 5% |
| Gas (flatulence) | 2% | 3% | 3% | 4% |
| Bloating (abdominal distension) | 2% | 3% | 3% | 4% |
| Dizziness | 2% | 4% | 5% | 4% |
| Low blood pressure (hypotension) | 0% | 1% | 1% | 2% |
The fatigue row counts "asthenia, fatigue, lethargy, malaise." Diarrhea includes frequent bowel movements, and constipation includes hard stools.
Looking at stomach side effects as one group, the share is flat: 56% at 5 mg, 56% at 10 mg and 56% at 15 mg, against 30% on placebo. What changes with the dose is which ones: vomiting and diarrhea go up, constipation goes down.
What about 2.5, 7.5 and 12.5 mg?
The label has no separate numbers for them. People in the trials were assigned a final dose of 5, 10 or 15 mg and reached it through "an escalation period of up to 20 weeks," so the 2.5, 7.5 and 12.5 mg weeks are inside those columns. The steps themselves, and the earliest week each one can start, are in the Zepbound dosage chart.
Are side effects worse after a dose increase?
That's when most of them happened. The label says: "The majority of nausea, vomiting, and/or diarrhea events occurred during dose escalation and decreased over time." And the dosing section gives that as the reason for the slow ladder: follow the escalation schedule "to reduce the risk of gastrointestinal adverse reactions," with at least 4 weeks on each dose before the next.
The label doesn't put a number of days on how long a flare after moving up a dose lasts. For the doctor's side of it, it says: "If patients do not tolerate a maintenance dosage, consider a lower maintenance dosage." Whether to stay on a step, go up or go back is your prescriber's decision. It helps to bring them a few weeks of notes on what you felt and when.
If you use birth control pills by mouth, the Medication Guide says they "may not work as well while using ZEPBOUND," and your healthcare provider may recommend another type "for 4 weeks after you start ZEPBOUND and for 4 weeks after each increase in your dose."
Constipation, hair loss, headache
Constipation is the one row that drops as the dose rises: 17% at 5 mg, 14% at 10 mg, 11% at 15 mg.
The label ties hair loss to the weight loss itself ("associated with weight reduction"). It was reported more often in women than in men on Zepbound, 7.1% against 0.5%, and nobody on Zepbound stopped the trials because of it.
Headache is a common search after a dose increase, but it isn't in the label's table of common side effects. If yours keeps coming back after shot day, write it down and bring the pattern to your prescriber. The Zepbound shot day tips cover the timing of the drug after each shot.
How many people stopped, by dose
Across both trials, 4.8% of people on 5 mg, 6.3% on 10 mg and 6.7% on 15 mg stopped Zepbound for good because of side effects, against 3.4% on placebo. Most did it "during the first few months of treatment due to gastrointestinal adverse reactions." Stopping because of stomach side effects alone came to 1.9%, 3.3% and 4.3%, against 0.5% on placebo.
Severe stomach side effects followed the same order: 1.7% at 5 mg, 2.5% at 10 mg, 3.1% at 15 mg, and 1% on placebo.
When to call your healthcare provider
The Medication Guide links nausea, vomiting and diarrhea to dehydration: they "may cause a loss of fluids (dehydration) which may cause kidney problems. 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."
It also says: "Tell your healthcare provider if you have stomach problems that are severe or will not go away."
For pancreatitis: "Stop using ZEPBOUND and call your healthcare provider right away if you have severe pain in your stomach area (abdomen) that will not go away, with or without nausea or vomiting. Sometimes you may feel the pain from your abdomen to your back."
For gallbladder problems, it says to tell your healthcare provider right away if you get symptoms, which may include:
- pain in your upper stomach (abdomen)
- fever
- yellowing of skin or eyes (jaundice)
- clay-colored stools
And for a serious allergic reaction: "Stop using ZEPBOUND and get medical help right away if you have any symptoms of a serious allergic reaction including:"
- swelling of your face, lips, tongue or throat
- problems breathing or swallowing
- severe rash or itching
- fainting or feeling dizzy
- very rapid heartbeat
Redness or itching where you inject is a different, local reaction. The Zepbound injection sites guide covers it.
Keeping track from one dose to the next
The trial numbers are averages over 72 weeks. Your own pattern is easier to see if you write down the dose, the shot date and how you felt in the days after. The printable shot log has room for all of it.
Sources
- Zepbound (tirzepatide) prescribing information, Eli Lilly, revised 08/2026Checked October 31, 2026
- Zepbound label and Medication Guide, DailyMed (National Library of Medicine)Checked October 31, 2026