In SURMOUNT-1, Zepbound averaged about 2.5% body-weight loss by week 4, 8.5% by week 12 and about 22.5% by week 72. The dose is raised in steps, so the effect builds over months; individual results vary widely. The label reports steady blood levels after 4 weeks of weekly doses.
When Zepbound reaches its full dose
- Weeks 1–4: 2.5 mg/week — Starting dose only; not approved for maintenance.
- Weeks 5–8: 5 mg/week — First maintenance option.
- Weeks 9–12: 7.5 mg/week
- Weeks 13–16: 10 mg/week — Second maintenance option.
- Weeks 17–20: 12.5 mg/week
- Week 21+: 15 mg/week — Third maintenance option and the maximum.
Expected weight-loss curve
Mean body-weight change across 72 weeks on Zepbound from the SURMOUNT-1 trial. Curve smoothed from published endpoints; individual results vary significantly.
Trial participants also received lifestyle counseling. Real-world results depend on dose adherence, side-effect tolerance, and lifestyle factors.
When to reassess
The Zepbound label sets no time point for judging whether it is working. Ask your prescriber when they plan to review your response, and do not change the dose on your own.
Why GLP-1 medicines work gradually, and what the first weeks usually feel like, is covered once for the whole class in how long GLP-1 medications take to work.
Common questions
How long does Zepbound stay in the body?
Zepbound has a half-life of about five days and is taken once weekly. The label reports steady blood levels after 4 weeks of weekly doses.
When should I talk to my prescriber if Zepbound isn't working?
The Zepbound label sets no time point for judging response. Ask your prescriber when they plan to review it, and do not change the dose on your own.