Tirzepatide side effects at each dose
How often each side effect was reported at 5, 10 and 15 mg in the Zepbound trials, when they tend to happen, and which ones need a doctor.
Key facts
- The most common are digestive: nausea in 25–29% of people at 5 to 15 mg, against 8% on placebo.
- They are most frequent in the weeks after each dose increase, which is why the dose rises slowly.
- Severe, persistent stomach pain, especially spreading to the back, needs urgent care: it can be pancreatitis.
- Tirzepatide is not used by anyone with a personal or family history of medullary thyroid cancer or MEN 2.
Side effects by dose
Share of adults reporting each side effect in the two main Zepbound weight trials1:
| Side effect | Placebo | 5 mg | 10 mg | 15 mg |
|---|---|---|---|---|
| Nausea | 8% | 25% | 29% | 28% |
| Diarrhoea | 8% | 19% | 21% | 23% |
| Vomiting | 2% | 8% | 11% | 13% |
| Constipation | 5% | 17% | 14% | 11% |
| Abdominal pain | 5% | 9% | 9% | 10% |
| Indigestion | 4% | 9% | 9% | 10% |
| Injection-site reactions | 2% | 6% | 8% | 8% |
| Fatigue | 3% | 5% | 6% | 7% |
| Allergic reactions | 3% | 5% | 5% | 5% |
| Burping | 1% | 4% | 5% | 5% |
| Hair loss | 1% | 5% | 4% | 5% |
| Reflux | 2% | 4% | 4% | 5% |
| Dizziness | 2% | 4% | 5% | 4% |
Women reported hair loss far more often than men; see side effects in women.
When side effects happen
The label ties the slow escalation, 2.5 mg at a time with at least 4 weeks on each dose, to reducing stomach side effects. They are most common after starting and after each increase, and usually ease as the body adjusts. Vomiting and diarrhoea that go on can dehydrate you, which is how a common side effect turns into kidney injury, so drink fluids and tell your prescriber if they persist.
Warning signs that need a doctor
- Severe stomach pain that does not go away, with or without vomiting, sometimes spreading to the back: possible pancreatitis. Stop and seek care.
- Pain in the upper right abdomen, fever, yellow skin or eyes: possible gallbladder problems.
- Swelling of the face, lips or throat, trouble breathing or a severe rash: allergic reaction. Seek urgent help.
- Little or no urine, or vomiting and diarrhoea you cannot keep up with: dehydration and kidney strain.
- Before surgery or sedation, tell the team you take tirzepatide: food can stay in the stomach longer.
The boxed warning
Frequently asked questions
What is the most common side effect of tirzepatide?
Nausea, reported by 25% to 29% of people at 5 to 15 mg in the Zepbound trials, against 8% on placebo.
Do side effects get worse at higher doses?
Vomiting and diarrhoea were somewhat more common at 15 mg than at 5 mg; nausea was similar from 5 to 15 mg. They peak after each dose increase.
How long do tirzepatide side effects last?
They are most common in the weeks after starting and after each increase, and usually ease as the body adjusts. Persistent symptoms should be reported.
When should I stop tirzepatide and call a doctor?
For severe, lasting stomach pain, signs of an allergic reaction, or vomiting and diarrhoea you cannot keep up with fluids.