Request ConsultationLilly EloraTZP combines eloralintide and tirzepatide to target amylin GIP and GLP 1 pathways for deeper weight loss. Explore its Phase 2b results, safety challenges, Phase 3 plans, and potential impact on the next generation of obesity treatments.
The obesity drug market is entering a new phase. GLP-1-based medicines have already transformed obesity treatment, but pharmaceutical companies are now looking beyond single-pathway therapies. The next major competition is focused on combining complementary biological mechanisms to achieve greater weight loss, improve metabolic health, and potentially provide broader benefits for people living with obesity and type 2 diabetes.
Eli Lilly is pushing this strategy with EloraTZP, an investigational combination of eloralintide and tirzepatide. Eloralintide is a selective amylin receptor agonist, while tirzpatide is a dual GIP and GLP-1 receptor agonist and the active ingredient in Zepbound.
On September 30, 2026, Lilly announced results from a 48-week Phase 2b study in 367 adults with obesity or overweight and type 2 diabetes. The highest-dose EloraTZP combination produced an average weight loss of 23.3%, equivalent to about 54.1 pounds, compared with 14.8% and 34.4 pounds with tirzepatide 15 mg alone. The highest-dose combination also reduced A1C by 2.9 percentage points compared with 2.4 percentage points with tirzepatide 15 mg alone.
These findings have created excitement around the possibility of a new generation of obesity medicines. However, EloraTZP remains investigational. The results do not yet establish that it has definitively beaten Zepbound in a Phase 3 head-to-head trial. Instead, it demonstrates that adding an amylin-based mechanism to tirzepatide produced greater weight loss than tirzepatide 15 mg alone in Lilly’s Phase 2b study.
What is EloraTZP?
EloraTZP is Lilly’s investigational combination of eloralintide and tirzepatide.
Eloralintide is a once-weekly selective amylin receptor agonist designed to preferentially activate the amylin 1 receptor. Amylin is a hormone naturally released after eating and contributes to appetite regulation and satiety, or the feeling of fullness. Eloralintide is designed to activate this pathway and potentially reduce appetite and food intake.Tirzepatide works through two different metabolic pathways. It activates the GIP and GLP-1 receptors, providing dual incretin activity.
EloraTZP therefore brings together three complementary metabolic pathways: Amylin, GIP, and GLP-1
These hormones are naturally involved in regulating hunger, satiety, and blood sugar after food intake; the combination therefore represents a multi-pathway approach to obesity rather than simply increasing activity through a single receptor.
Lilly plans to advance ELoraTZP into phase 3 as a co-formulated medicine, potentially creating a more streamlined treatment approach for patients.
Why Add Amylin to Tirzepatide?
Obesity is a complex metabolic disease involving multiple biological systems. Appetite, hunger, satiety, glucose metabolism, energy balance, and body-weight regulation are influenced by several hormones and signaling pathways.
GLP-1-based therapies have demonstrated that targeting one important pathway can produce substantial weight loss. Tirzepatide expanded this concept by targeting both GIP and GLP-
The addition of amylin represents another step in this evolution.
Amylin has a different biological role from GIP and GLP-1. It is naturally released after meals and contributes to the body’s satiety signals. Activating the amylin pathways alongside incretin pathways could therefore provide complementary effects.
This creates a potential progression in obesity pharmacology:
GLP-1-GIP/GLP-1-Amylin + GIP/GLP-1
The strategy could allow future therapies to produce greater weight loss without relying exclusively on stronger activity through one pathway.
How Did EloraTZP Perform?
The phase 2b trial evaluated EloraTZP in 367 adults with obesity or overweight and type 2 diabetes over 48 weeks. Participants received different doses of tirzepatide, tirzepatide, their combinations, or placebo.
- The strongest result came from the combination of tirzepatide 9 mg and tirzepatide 15 mg.
- Participants receiving this combination lost an average of:
- 23.3% of body weight - this represents approximately 54.6 pounds
- Participants receiving tirzepatide 15 mg alone lost:
- 14.8% of body weight - approximately 34.4 pounds
- The difference between the two treatments was 8.5 percentage points.
Key Phase 2b Results
- Eloralintide 9 mg + tirzepatide 15 mg: 23.3 % average weight loss
- Tirzepatide 15 mg: 14.8 % average weight loss
- Difference: 8.5 percentage points
- Highest combination weight loss: 54.1 pounds
- Tirzepatide comparator: 34.4 pounds
- Highest combination A1C reduction: 2.9 percentage points
- Tirzepatide 15 mg A1C reduction: 2.4 percentage points
- Study duration: 48 weeks
- Participants: 367 adults
- Next development stage: Phase 3 planned for Q4 2026
The study also showed increasing weight loss across different combination doses. Eloralintide 3 mg plus tirzepatide 5 mg produced 13.2% average weight loss, while eloralintide 6 mg plus tirzepatide 5 mg produced 19.4%. The 6 mg plus 10 mg combination produced 19.9%, and the highest combination reached 23.3%.
This dose-related pattern provides additional support for continued clinical development.
ElorzaTZP and Blood Sugar Control
The potential impact of EloraTZP goes beyond weight loss
Because the Phase 2b study involved adults with type 2 diabetes, A1C reduction was an important measure of metabolic performance.
The highest-dose EloraTZP combination reduced A1C by an average of 2.9 percentage points, compared with 2.4 percentage points with tirzepatide 15 mg alone.
Eloralintide alone produced an A1C reduction of up to 1.4 percentage points, while the combination generated stronger reductions.
This is significant because obesity and type 2 diabetes frequently occur together. A treatment capable of addressing both body weight and blood glucose could have a broader role in cardiovascular disease management.
However, Phase 2b results cannot establish whether the treatment will reduce long-term cardiovascular events or other complications. Those questions require larger and longer clinical studies.
The Tolerability Challenge
Higher efficacy can also create treatment-management challenges
The most common adverse events reported in the Phase 2b study were gastrointestinal-related and generally mild or moderate. They occurred primarily during dose escalation and were more frequent in the combination groups than with eloralinitide or tirzepatide alone.
Treatment discontinuation due to adverse events ranged from 10.8% to 27.0% across EloraTZP groups, compared with 2.9% with tirzepatide 15 mg. This is an important consideration because obesity treatment is generally long term.
A medicine must not only produce substantial weight loss but also provide an acceptable treatment experience that patients can maintain over time.
The future success of EloraTZP will therefore depend on balancing:
- Greater weight loss
- Blood-sugar improvement
- Gastrointestinal tolerability
- Dose escalation
- Long-term safety
- Patient adherence
- Treatment convenience
Lilly plans to use an optimized escalation schedule as it moves the co-formulated product into Phase 3.
From Separate Injections to a Co-Formulated Medicine
In the Phase 2b study, eloralinitide and tirzepatide were administered as separate injections.
Lilly plans to advance a co-formulated EloraTZP product into Phase 3 by the end of 2026.
Co-formulation could become an important part of the product’s future commercial strategy.
A successful formulation is also a major development challenge. The final product must deliver appropriate doses of both components consistently while maintaining stability, quality, safety, and convenient administration.
However, pharmaceutical formulation is also a major development challenge. The final product must deliver appropriate doses of both components consistently while maintaining stability, quality, safety, and convenient administration.
Therefore, pharmaceutical formulation is also a major development challenge. The final product must deliver appropriate doses of both components consistently while maintaining stability, quality, safety, and convenient administration.
Therefore, EloraTZP’s future will depend not only on clinical efficacy but also on formulation, manufacturing, scalability, and patient usability.
Pharmaceutical formulation is also a major development challenge. The final product must deliver appropriate doses of both components consistently administration.
Therefore, EloraTZP’s future will depend not only on clinical efficacy but also on formulation, manufacturing, scalability, and patient usability.
How EloraTZP Could Reshape the Obesity Drug Market
The obesity drug market is moving toward therapies capable of producing substantial and sustained weight reduction.
EloraTZP could influence this market in several ways.
- Moving Beyond Single-Pathway Therapies: The combination demonstrates the potential of simultaneously targeting several biological pathways rather than relying on one mechanism.
- Creating New Product Differentiation: As more GLP-1 and GLP/GLP-1 medicines enter the market, companies need new ways to differentiate their products. Amylin provides another mechanism for developing next-generation therapies.
- Reshaping the Efficacy Benchmark: If Phase 3 confirms the 23.3% results, weight-loss levels above 20% could become an increasingly important benchmark for advanced obesity treatments.
- Expanding Cardiometabolic Treatment: The combination’s effects on both weight and A1C could strengthen the role of obesity medicines within broader cardiometabolic treatment strategies.
- Increasing Competition: Successful Combination therapies could encourage pharmaceutical companies to explore amylin and additional metabolic pathways, accelerating innovation across the obesity drug pipeline.
- Lilly’s Broader Obesity Pipeline: EloraTZp is only one part of Lilly’s next-generation cardiometabolic strategy.
The company is also developing retatruditde an investigational triple hormone receptor agonist targeting GIP, GLP-1, and glucagon.
In the phase 3 TRIUMPH-2 study, Lilly reported that adults with obesity
The company is also developing retatrutide, an investigational triple hormone receptor agonist targeting GIP, GLP-1, and glucagon.
In the phase 3 TRIUMP-2 study, Lilly reported that adults with obesity or overweight and type 2 diabetes receiving retatrutide achieved up to 20.8% average weight loss at 8 weeks, along with A1C improvements.
This creates an interesting strategic contrast.
EloraTZP: Amylin+GIP+GLP-1
Retatrutide: GIP+GLP+Glucagon
Both approaches target three metabolic pathways, but through different biologicals mechanisms.
This suggests that Lilly is exploring multiple routes towards deeper weight loss rather than depending on a single future product.
Amyline Could Become the Next Major Obesity Target
Amylin is emerging as an important target in obesity drug development.
The hormone is naturally released after food intake and contributes to satiety and appetite regulation. Selective amylin receptor agonists aim to reproduce these effects through pharmacological activation.
Lilly is developing eloralinitide both as a standalone treatment and as part of the EloraTZP combination. Eloralinitide has already progressed into Phase 3 development as a standalone therapy for obesity and related conditions.
This creates two potential opportunities:
- Eloralinitide as a Standalone obesity medicine
- Eloralinitide combines with tirzepatide as a multi-pathway therapy
If the clinical program succeeds, amylin could become one of the major mechanisms shaping the next generation of obesity medicines.
Challenges to Commercial Adoption
Despite the strong Phase 2b findings, EloraTZP faces several challenges.
- Phase 3 validation: The most important question is whether the Phase 2b results can be replicated in larger and more diverse patient populations.
- Long -Term Safety: Obesity is a chronic disease, meaning patients may use treatment for years. Long-term safety will therefore be essential.
- Tolerability: The higher discontinuation rates observed in some combination groups will require careful evaluation during Phase 3.
- Treatment Cost: Advanced specialty medicine can be expensive. Pricing, insurance coverage, reimbursement, and healthcare access could strongly influence adoption.
- Patient Adherence: Greater weight loss will have limited real-world value of patient discontinue therapy because of side effects, treatment burden, cost, or, other factors.
- Manufacturing Scale: If EloraTZP demonstrates strong Phase 3 results, Lilly will need to manufacture the product at a scale capable of serving a large global obesity population.
- Competitive Pressure: The market is rapidly expanding beyond traditional injectable GLP-1 medicine. Oral therapies, amylin agonists, dual agonists, triple agonists, and other metabolic approaches could compete for the same patient populations.
The Strategic Battle for the Next GLP-1 Revolution
The obesity drug race is no longer simply about developing another GLP-1 medicine.
The industry is moving toward multi-hormone pharmacology
The potential evolution can be summarized as:
GLP-1-GIP/GLP-1-Multi-pathway metabolic therapies
EloraTZP represents an important step in this transition.
Its significance is not only the 23.3% weight-loss result. The significance is the strategy behind it: Lilly is testing whether an established GIP/GLP-1 foundation can be enhanced by adding a separate satiety pathway.
If successful, this could become a blueprint for future obesity medicines.
Pharmaceutical companies may increasingly compete by combining complementary mechanisms instead of simply creating stronger versions of existing therapies.
That could fundamentally change obesity drug discovery and development.
What Could the Future of obesity Treatment Look Like?
The next generation of obesity treatment could become more individualized.
Some patients may achieve sufficient weight reduction with a single mechanism. Others may benefit from combinations that target several metabolic pathways.
Future treatment decisions could potentially consider:
- Degree of obesity
- Type 2 disbetes status
- Cardiovascular risk
- Weight-loss target
- Metabolic response
- Treatment tolerance
- Long-term maintenance
- Individual response to different mechanisms
- This could shift obesity treatment toward a more patient-specific approach.
Combination therapies could also become important for long-term weight management. Sustaining significant weight reduction remains a major challenge in chronic obesity treatment.
If multi-pathways medicine can deliver deeper and durable weight loss with manageable tolerability, it could become an important part of long-term obesity care.
The Future horizon of EloraTZP
Lilly plans to initiate Phase 3 studies of EloraTZP in the fourth quarter of 2026, advancing a co-formulated version with an optimized dose-escalation schedule.
The transition from Phase 2b to Phase 3 will be critical.
Several questions will determine whether EloraTZP becomes a major obesity medicine:
- Can the 23.3% average weight-loss result be reproduced?
- Can gastrointestinal adverse events be effectively managed?
- Can patients remain on treatment for the long term?
- Will the co-formulation improve convenience?
- Will the combination demonstrate broader metabolic benefits?
- Can Lilly manufacture the treatment at a global scale?
- The answer will determine whether EloraTZP becomes another promising investigational therapy or a major new treatment platform.
Conclusion
Lilly’s EloraTZP results represent an important development in the evolution of obesity medicine.
The combination of eloralinitide and tirzepatide produced up to 23.3% average weight loss at 48 weeks, compared with 14.8% with tirzepatide 15 mg alone, while also delivering greater A1C reduction in adults with obesity or overweight and type 2 diabetes.
The finding should not yet be described as a definitive victory over Zepbound. EloraTZP remains investigational, and its strongest evidence currently comes from a Phase 2b study. Larger Phase 3 trials will be needed to determine whether the treatment offers an acceptable long-term safety and tolerability profile.
Nevertheless, the result highlights where the obesity drug market may be heading.
The next revolution could involve where the obesity drug market may be heading.
The Next revolution could involve amylin, GIP, GLP-1, glucagon, and other metabolic pathways working together.
With EloraTZP moving toward Phase 3 and other multi-pathway medicines progressing across the industry, obesity treatment is entering a new competitive era.
The future may therefore not be about replacing GLP-1.
About the Authors
Aditi Shivarkar
Aditi, Vice President at Precedence Research, brings over 15 years of expertise at the intersection of technology, innovation, and strategic market intelligence. A visionary leader, she excels in transforming complex data into actionable insights that empower businesses to thrive in dynamic markets. Her leadership combines analytical precision with forward-thinking strategy, driving measurable growth, competitive advantage, and lasting impact across industries.
Aman Singh
Aman Singh with over 13 years of progressive expertise at the intersection of technology, innovation, and strategic market intelligence, Aman Singh stands as a leading authority in global research and consulting. Renowned for his ability to decode complex technological transformations, he provides forward-looking insights that drive strategic decision-making. At Precedence Research, Aman leads a global team of analysts, fostering a culture of research excellence, analytical precision, and visionary thinking.
Piyush Pawar
Piyush Pawar brings over a decade of experience as Senior Manager, Sales & Business Growth, acting as the essential liaison between clients and our research authors. He translates sophisticated insights into practical strategies, ensuring client objectives are met with precision. Piyush’s expertise in market dynamics, relationship management, and strategic execution enables organizations to leverage intelligence effectively, achieving operational excellence, innovation, and sustained growth.