Eloralintide vs Semaglutide
Semaglutide (NN9535) is the most-published GLP-1 receptor agonist and an approved prescription medicine. Eloralintide (LY3841136) is Lilly's investigational once-weekly selective amylin receptor agonist, now in the ENLIGHTEN Phase 3 programme. They act on different hormone systems, so this page compares them as research compounds rather than as rivals.
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| Eloralintide | Semaglutide | |
|---|---|---|
| Development code | LY3841136 | NN9535 |
| Receptor target | Amylin receptors (selective) | GLP-1 receptor (selective) |
| Hormone it mimics | Amylin, released with insulin | GLP-1, a gut incretin |
| Administration in trials | Once weekly subcutaneous | Once weekly subcutaneous |
| Development stage | Investigational, ENLIGHTEN Phase 3 | Approved medicine in many territories |
| Headline trial result | Phase 2: 9.5% to 20.1% at 48 weeks | STEP 1: 14.9% at 68 weeks |
| Peptx availability | Waitlist, UK single vials | Stocked in several vial sizes |
- Development code
- LY3841136NN9535
- Receptor target
- Amylin receptors (selective)GLP-1 receptor (selective)
- Hormone it mimics
- Amylin, released with insulinGLP-1, a gut incretin
- Administration in trials
- Once weekly subcutaneousOnce weekly subcutaneous
- Development stage
- Investigational, ENLIGHTEN Phase 3Approved medicine in many territories
- Headline trial result
- Phase 2: 9.5% to 20.1% at 48 weeksSTEP 1: 14.9% at 68 weeks
- Peptx availability
- Waitlist, UK single vialsStocked in several vial sizes
Two different hormone systems
Semaglutide mimics GLP-1, the gut incretin that slows gastric emptying and signals satiety through receptors in the brain and pancreas. It is the reference compound for GLP-1 receptor research, with more than a decade of published data behind it.
Eloralintide mimics amylin, the hormone released alongside insulin from pancreatic beta cells. Amylin acts mainly in the hindbrain on satiety and meal size, through receptors built from the calcitonin receptor and a receptor activity-modifying protein. Eloralintide is designed to be selective for those amylin receptors.
What the trials show
In Lilly's Phase 2 trial, published in The Lancet in November 2025, eloralintide produced mean weight reductions of 9.5% to 20.1% at 48 weeks across its dose arms, against 0.4% with placebo, in 263 adults with obesity or overweight and without type 2 diabetes. Gastrointestinal effects were mostly mild to moderate and more frequent at higher doses.
Semaglutide's STEP 1 trial reported 14.9% mean weight reduction at 68 weeks against 2.4% with placebo. The trials differ in length, population and design, so the numbers are not a head-to-head result.
Why researchers look at them together
Because they work through separate receptor systems, amylin and GLP-1 agonists are studied in combination. The best-known pairing is cagrilintide with semaglutide (CagriSema). Lilly's ENLIGHTEN-6 study tests eloralintide in participants already treated with a weekly incretin, and its combination with tirzepatide reported a 48-week Phase 2b in September 2026.
Bottom line for research labs
Semaglutide is the default reference for GLP-1 receptor research, with the deepest published record. Eloralintide is the newer tool for amylin receptor work and for studying how amylin and incretin pathways combine. They answer different research questions.