Brenipatide vs Tirzepatide
Brenipatide (LY3537031) and Tirzepatide (LY3298176) are both dual agonists of the GIP and GLP-1 receptors. Tirzepatide is approved for type 2 diabetes and weight management and has a large phase 3 record. Brenipatide is investigational, has a longer reported half-life, and is being tested mainly in addiction, mood disorders, schizophrenia and asthma. This page compares them as research compounds.
Not yet stocked
Register interest
Brenipatide is not currently supplied by Peptx. Leave an email address and we will notify you once verified reference material is available. No purchase, no obligation, and the address is used for this notice only.
| Brenipatide | Tirzepatide | |
|---|---|---|
| Development code | LY3537031 | LY3298176 |
| Receptor targets | GIP and GLP-1 (dual) | GIP and GLP-1 (dual) |
| Molecule | Synthetic peptide with a C20 fatty diacid | Synthetic peptide with a C20 fatty diacid |
| Reported half-life | 9 to 12 days (phase 1) | About 5 days |
| Main trial focus | Alcohol, opioid and smoking studies, mood disorders, schizophrenia, asthma | Type 2 diabetes, obesity and related conditions |
| Published efficacy data | None yet | SURMOUNT-1: 15.0% to 20.9% at 72 weeks (placebo 3.1%) |
| Status | Phase 3 (alcohol use disorder, major depressive disorder) | Approved in the UK, EU and US |
| Peptx availability | Not stocked, waitlist on this page | UK single vials and Factory Direct kits |
- Development code
- LY3537031LY3298176
- Receptor targets
- GIP and GLP-1 (dual)GIP and GLP-1 (dual)
- Molecule
- Synthetic peptide with a C20 fatty diacidSynthetic peptide with a C20 fatty diacid
- Reported half-life
- 9 to 12 days (phase 1)About 5 days
- Main trial focus
- Alcohol, opioid and smoking studies, mood disorders, schizophrenia, asthmaType 2 diabetes, obesity and related conditions
- Published efficacy data
- None yetSURMOUNT-1: 15.0% to 20.9% at 72 weeks (placebo 3.1%)
- Status
- Phase 3 (alcohol use disorder, major depressive disorder)Approved in the UK, EU and US
- Peptx availability
- Not stocked, waitlist on this pageUK single vials and Factory Direct kits
Same receptors, different goals
Both molecules activate the receptors for GIP and GLP-1, the two incretin hormones released from the gut after a meal. Both are synthetic peptides carrying a fatty acid that binds albumin in the blood, which slows clearance. The FDA substance register describes brenipatide with several non-natural amino acids that resist enzyme breakdown.
The clearest measured difference is duration. Phase 1 data presented at Psych Congress 2026 reported a half-life of 9 to 12 days for brenipatide, against about 5 days for tirzepatide. A longer half-life means steadier exposure between doses, which matters in trials that run for a year or more.
Why the trial programmes look so different
Tirzepatide was developed for type 2 diabetes and obesity, and its SURPASS and SURMOUNT trials enrolled tens of thousands of people. Brenipatide's nine registered trials are mostly elsewhere: alcohol use disorder and major depressive disorder in phase 3, and smoking relapse, opioid use disorder, bipolar disorder, schizophrenia and asthma in phase 2.
The idea behind the addiction trials comes from GLP-1 receptors in brain reward areas. In small human trials, exenatide and semaglutide improved some drinking measures but not others. The contribution of GIP receptor activity to these effects is less studied, and no trial compares brenipatide with tirzepatide.
Where weight data will come from
Tirzepatide's SURMOUNT-1 trial, published in the New England Journal of Medicine in 2022, reported body weight reductions of 15.0%, 19.5% and 20.9% at 72 weeks across its three arms, against 3.1% on placebo. Brenipatide has no published weight data. Its phase 1b study in people with overweight or obesity measures body weight change at 29 weeks, and the primary measure in its schizophrenia trial is body weight change at 52 weeks in participants with a BMI of 25 or more.
Bottom line for research labs
Brenipatide and Tirzepatide share a receptor profile but not a purpose. Tirzepatide is the established dual-agonist reference with years of trial data. Brenipatide is a longer-lasting member of the same class whose trials ask a different question: whether incretin signalling changes addiction, mood and inflammation outcomes. Until its trials report, tirzepatide remains the dual agonist with evidence behind it.