Summary of Key Points
Pfizer’s GLP-1 weight loss drug, Enogluceptin, outperformed the current market leader, Novo Nordisk’s Semaglutide, in a head-to-head study (direct comparison) with significantly better weight reduction results (20% weight loss vs 9.5%). This marks a shift in the domestic GLP-1 weight loss drug market from a phase of “availability” to one of “efficacy competition.” The news also highlights the severity of obesity in China (over 30% of adults are overweight, and 16% are obese), as well as the challenges associated with existing GLP-1 drugs, such as plateaus in effectiveness, weight rebound, and side effects. It outlines two main directions for future research and development: combining multiple targets or optimizing a single target.
Detailed Analysis
1. How much better is Pfizer’s new drug compared to Semaglutide?
This study was a direct comparison: both drugs were administered once a week at a dose of 2.4mg, and 163 obese patients (BMI≥30) from 17 hospitals in China were divided into two groups. After 20 weeks, the results were clear:
- The Enogluceptin group achieved an average weight loss of 12.8%, compared to 9.5% for the Semaglutide group (a difference of 35%).
- The reduction in waist circumference was also greater with Enogluceptin.
- The proportion of patients who lost at least 10% of their body weight was 74% with Enogluceptin, compared to only 40% with Semaglutide (almost twice as many).
Experts note that these results need to be confirmed by larger-scale phase III trials before a definitive conclusion can be drawn.
2. How dominant has Semaglutide been in the past?
Since its launch in China in 2021, Semaglutide has almost monopolized the GLP-1 weight loss drug market:
- Sales in hospitals exceeded 4.1 billion yuan in 2024;
- Sales in the first three quarters of 2025 were 3.4 billion yuan (a year-on-year increase of 6.6%).
- It accounted for 99.95% of the domestic hospital-based GLP-1 market—meaning that nearly all GLP-1 weight loss drugs prescribed by hospitals are Semaglutide. The introduction of Pfizer’s new drug could potentially change this dominant position.
3. How do GLP-1 weight loss drugs work?
In simple terms, the human body produces a hormone called GLP-1, which sends signals to the brain indicating fullness and slows down gastric emptying, making one feel fuller with smaller portions. GLP-1 weight loss drugs mimic this mechanism, making the body believe it has eaten enough, resulting in less food intake and weight loss. This approach is more sustainable than dieting or exercise, making them a “new hope” for obesity treatment.
4. What are the current challenges with existing GLP-1 drugs?
Despite their effectiveness, there are three major issues:
- Plateaus: Weight loss stops after prolonged use.
- Weight rebound: Weight returns after stopping the drug.
- Side effects: Nausea and vomiting may occur with higher doses, deterring many patients from using the drugs long-term.
These issues undermine confidence in the long-term efficacy of these treatments and are key challenges for the industry to overcome.
5. Where is the future of GLP-1 drugs heading?
There are two main research directions:
- Combining multiple targets: Integrating GLP-1 with other weight loss-related factors (such as GIP) to enhance effectiveness.
- Optimizing a single target: Improving the signaling pathway of GLP-1 (e.g., enhancing the cAMP-dependent mechanism) to potentially reduce side effects while maintaining efficacy.
However, more research is needed to verify the safety and durability of these new approaches, especially for long-term use.
Overall, the GLP-1 weight loss drug market is moving towards competition, offering patients more effective and tolerable options in the future. However, overcoming the long-term usage challenges remains a critical task for the industry.