Tirzepatide SURMOUNT-CN: 17.5% Weight Loss in Chinese Adults With Obesity (JAMA Phase 3) | Research

The takeaway

JAMA-published phase 3 trial shows tirzepatide 15 mg achieved 17.5% weight loss in Chinese adults with obesity, with 85.8% of participants losing at least 5% of body weight over 52 weeks.

-17.5% body weight
with tirzepatide 15 mg in Chinese adults over 52 weeks, published in JAMA as the SURMOUNT-CN phase 3 trial

What the researchers found

Tirzepatide 15 mg: -17.5% body weight at 52 weeks (vs -2.3% placebo, P<0.001). 10 mg: -13.6%. 85.8% achieved ≥5% weight loss with 15 mg. 95.7% trial completion. GI side effects mostly mild-moderate with <5% discontinuation.

Why it matters

China has the world's largest population affected by obesity. This JAMA trial establishes tirzepatide as highly effective in Chinese adults, supporting regulatory approval and addressing the growing obesity epidemic in Asia where BMI thresholds differ from Western populations.

The numbers in context

Phase 3 trial at 29 centers in China, September 2021 to December 2022, in adults with BMI above obesity/overweight thresholds.

How the study worked

Randomized, double-blind, placebo-controlled phase 3 trial (SURMOUNT-CN). 210 Chinese adults (BMI ≥28 or ≥24 with comorbidities), randomized 1:1:1 to tirzepatide 10 mg, 15 mg, or placebo weekly for 52 weeks at 29 Chinese centers. ITT analysis. ClinicalTrials.gov NCT05024032.

Who was studied

Chinese adults aged ≥18 with obesity or overweight with comorbidities across 29 centers

What this study cannot tell us

52-week duration does not capture long-term weight maintenance or regain after stopping treatment. Moderate sample size (210 participants). Asian-specific BMI cutoffs (≥24/28) differ from Western definitions (≥25/30). Cost and access in China's healthcare system not addressed. Excludes diabetes patients.

How to read the evidence

Strong evidence: JAMA-published randomized, double-blind, placebo-controlled phase 3 trial with 95.7% completion rate and robust statistical significance.

When this study was published

Published in 2024 in JAMA. Conducted September 2021-December 2022. Landmark trial for tirzepatide in Chinese/Asian populations.

The bigger picture

SURMOUNT-CN extends the global evidence for tirzepatide to Chinese/Asian populations, confirming that GLP-1/GIP dual agonism is effective across ethnic groups. As Asian obesity rates climb — often with different metabolic risk profiles at lower BMIs — having proven treatments specifically validated in these populations is critical for global obesity management.

Questions still open

Do Chinese patients maintain weight loss beyond 52 weeks with continued tirzepatide treatment?
How does tirzepatide's effectiveness in Chinese adults compare to semaglutide in the same population?
Will tirzepatide be accessible and affordable through China's healthcare system?

Common questions

How much weight can tirzepatide help Chinese patients lose?

In this JAMA trial, tirzepatide 15 mg produced 17.5% average weight loss (about 16 kg/35 lbs) over one year. Nearly 86% of participants lost at least 5% of their body weight. These results are similar to tirzepatide trials in other populations.

What side effects did Chinese patients experience?

The most common side effects were gastrointestinal — nausea, diarrhea, and decreased appetite. Most were mild to moderate, and fewer than 5% of participants stopped treatment due to side effects. The overall safety profile was consistent with other tirzepatide trials.

Read the original research

Tirzepatide for Weight Reduction in Chinese Adults With Obesity: The SURMOUNT-CN Randomized Clinical Trial.

JAMA, 332(7), 551-560

View on PubMed ↗Publisher’s paper ↗

Citation

Zhao, Lin; Cheng, Zhifeng; Lu, Yibing; Liu, Ming; Chen, Hong; Zhang, Min; Wang, Rui; Yuan, Yuan; Li, Xiaoying. (2024). Tirzepatide for Weight Reduction in Chinese Adults With Obesity: The SURMOUNT-CN Randomized Clinical Trial.. JAMA, 332(7), 551-560. https://doi.org/10.1001/jama.2024.9217