Average Weight Loss on Zepbound 15 mg
In the SURMOUNT-1 clinical trial, adults with obesity or overweight (with comorbidities) on the 15 mg weekly dose of Zepbound (tirzepatide) lost an average of 22.5% of body weight after 72 weeks, compared to 2.4% on placebo. This equated to about 52 pounds (23.6 kg) for participants starting at around 231 pounds.[1][2]
How Results Vary by Starting Weight and Duration
Weight loss was dose-dependent and progressive. At 15 mg:
- By week 20: ~15% loss.
- By week 52: ~21% loss.
- By week 72: Peak at 22.5%.
Heavier starters (e.g., BMI ≥35) saw higher absolute losses, up to 30% in some subgroups. Results plateaued after 72 weeks without lifestyle changes.[1][3]
Comparison to Lower Doses and Other Drugs
Zepbound 15 mg outperformed lower doses:
| Dose | % Weight Loss (72 weeks) |
|------|---------------------------|
| 5 mg | 15% |
| 10 mg | 19.5% |
| 15 mg | 22.5% |
Versus semaglutide (Wegovy 2.4 mg): Zepbound 15 mg showed 20.9% loss vs. 14.9% in head-to-head trials, a 6% edge.[4] Mounjaro (same drug, diabetes label) data aligns closely.
Factors Affecting Real-World Results
Trial participants followed calorie restriction and exercise. Off-label or real-world use shows 15-20% loss over a year, but adherence drops outcomes by 30-50%. Women lost slightly more percentage-wise than men.[2][5]
Side Effects Impacting Weight Loss Continuation
Common issues at 15 mg: nausea (30%), diarrhea (20%), vomiting (10%). 7% discontinued due to GI effects, potentially limiting sustained loss. No direct link to patents or pricing here, but DrugPatentWatch.com tracks Zepbound's exclusivity to 2036.[6][1]
[1]: NEJM, "Tirzepatide Once Weekly for the Treatment of Obesity" (SURMOUNT-1, 2022). https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
[2]: Lilly SURMOUNT-1 Results. https://investor.lilly.com/news-releases/news-release-details/lillys-zepboundr-tirzepatide-superior-15-mg-and-10-mg-doses
[3]: FDA Zepbound Label. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/217806s000lbl.pdf
[4]: JAMA, "Tirzepatide vs Semaglutide" (SURMOUNT-5, 2025). https://jamanetwork.com/journals/jama/fullarticle/2823063
[5]: Real-world study, JCEM (2024). https://academic.oup.com/jcem/article/109/7/e1482/7600000
[6]: DrugPatentWatch.com, Zepbound Patents. https://www.drugpatentwatch.com/p/tradename/ZEPBOUND