Ask before you push throughThis page describes what the FDA label and the trials report on average. Severe or persistent vomiting, diarrhea or abdominal pain is a reason to contact a prescriber, not to wait.
When do Zepbound side effects start?
They can start with the first 2.5 mg dose and tend to cluster after each increase. In SURMOUNT-1 the most common side effects were gastrointestinal, mostly mild to moderate, and “occurring primarily during dose escalation”.[2] The label's pooled data say the same: most nausea, vomiting and diarrhea came during escalation and decreased over time.[1]
| Weeks | Dose | What changes |
|---|---|---|
| 1–4 | 2.5 mg | First doses ever |
| 5–8 | 5 mg | Increase from 2.5 mg in week 5 |
| 9–12 | 7.5 mg | Increase from 5 mg in week 9 |
| 13–16 | 10 mg | Increase from 7.5 mg in week 13 |
| 17–20 | 12.5 mg | Increase from 10 mg in week 17 |
| 21 onward | 15 mg | Increase from 12.5 mg in week 21 |
Each row after the first is a new increase. Someone who stops at 5 or 10 mg has fewer increase weeks than someone who climbs to 15 mg.[1]
How long the dose-increase period lasts
In the Zepbound trials, escalation took up to 20 weeks.[1] On the fastest schedule the last increase is in week 21, so the period when stomach side effects are most likely runs through roughly the first 5 months. The label lets the dose stay lower if a higher one is not tolerated: “If patients do not tolerate a maintenance dosage, consider a lower maintenance dosage.”[1] The schedule itself is on the tirzepatide dosage chart.
How bad and how often
About 56% of people on each Zepbound dose had at least one gastrointestinal side effect, against 30% on placebo, but few stopped because of it.[1]
| Placebo | 5 mg | 10 mg | 15 mg | |
|---|---|---|---|---|
| Nausea | 8% | 25% | 29% | 28% |
| Stopped because of GI effects | 0.5% | 1.9% | 3.3% | 4.3% |
| Severe GI reactions | 1% | 1.7% | 2.5% | 3.1% |
The head-to-head SURMOUNT-5 trial found the same pattern for both tirzepatide and semaglutide: gastrointestinal events were the most common, mostly mild to moderate, and occurred primarily during dose escalation.[3]
Zepbound side effects long-term
Some label warnings are not tied to the dose-increase weeks and can appear at any time, so “long-term” here means for as long as the medicine is taken. The label lists acute gallbladder disease, acute pancreatitis, kidney injury from dehydration, serious allergic reactions and, in people with diabetes, low blood sugar with insulin or sulfonylureas.[1] Hair loss in the trials was associated with weight reduction.[1] The longest label data come from trials of up to 72 weeks and a withdrawal trial that ran to 88 weeks.[1][4] The thyroid C-cell tumor warning is based on rat studies; whether tirzepatide causes these tumors in humans is unknown.[1] Full rates are on Zepbound side effects.
How long Zepbound stays in the body after stopping
About half of the drug leaves the body every 5 to 6 days, so effects tied to the drug fade over several weeks after the last dose.[1] Using a 5-day half-life:
| Remaining | Days | About |
|---|---|---|
| 50% | 5 | 0.7 weeks |
| 25% | 10 | 1.4 weeks |
| 10% | 17 | 2.4 weeks |
| 5% | 22 | 3.1 weeks |
| 1% | 33 | 4.7 weeks |
The label also notes that slowed stomach emptying, which affects birth control pills, is largest after the first dose and diminishes over time.[1] Day-by-day decay is on tirzepatide half-life.
Warning signs the label lists
Four situations in the label call for prompt action rather than waiting for side effects to pass.
- Suspected pancreatitis: the label says to discontinue Zepbound.[1]
- Suspected gallbladder inflammation: gallbladder studies and follow-up are indicated.[1]
- Signs of a serious allergic reaction: prompt medical attention.[1]
- Planned surgery or sedation: tell the care team, because of a risk of pulmonary aspiration.[1]
Related
- Side effects in femalesHair loss, birth control, pregnancy
- Missed doseRestart questions after a gap
- Dosage for weight lossWhat each dose achieved
Frequently asked questions
How long do Zepbound side effects last?
Stomach side effects were most common during dose increases, which lasted up to 20 weeks in the trials, and decreased over time after that.[1]
When do Zepbound side effects start?
What are the long-term side effects of Zepbound?
Warnings not tied to dose increases include gallbladder disease, pancreatitis, kidney injury from dehydration and serious allergic reactions. The thyroid tumor warning comes from rat studies; human risk is unknown.[1]
Do Zepbound side effects go away after stopping?
The drug clears over weeks: with a half-life of about 5 to 6 days, around 2% of the last dose is left after 4 weeks.[1]
Sources
- Zepbound (tirzepatide) injection: prescribing information, Medication Guide and Instructions for Use
- Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1)
- Aronne LJ et al. Tirzepatide as compared with semaglutide for the treatment of obesity (SURMOUNT-5)
- Aronne LJ et al. Continued treatment with tirzepatide for maintenance of weight reduction (SURMOUNT-4)