Mechanism Comparison
| Property | Retatrutide (LY3437943) | Cagrilintide (AM833) |
|---|---|---|
| Class | Triple GLP-1+GIP+GCGR agonist | Long-acting amylin analog |
| Primary receptor | GLP-1R, GIPR, GCGR | AMY1R, AMY2R, AMY3R (calcitonin) |
| Administration | SC injection, weekly | SC injection, weekly |
| Weight loss mechanism | Appetite + energy expenditure + fat oxidation | Appetite + gastric emptying + satiety signals |
| Half-life | ~6 days | ~7–8 days |
Efficacy Data
Phase 2 data for Cagrilintide as a monotherapy showed approximately 10.8% weight reduction at 26 weeks in the 4.5 mg arm — meaningful but below the efficacy of Retatrutide monotherapy at equivalent timepoints.
The most significant Cagrilintide research involves its combination with Semaglutide (CagriSema), which produced up to 15.6% weight loss at 32 weeks in Phase 2 — demonstrating that amylin and GLP-1 receptor pathways are highly complementary.
Retatrutide's Phase 2 data at 48 weeks showed up to 22.8% body weight reduction — currently the highest of any single research compound in the GLP-1 class.
Different Mechanisms, Complementary Research Value
Retatrutide and Cagrilintide act through entirely different receptor systems. Retatrutide works through incretin and glucagon pathways (gut-brain-liver axis), while Cagrilintide works through the amylin system (pancreatic-brain axis). This makes them research tools for different aspects of metabolic regulation:
- Retatrutide research: incretin amplification, GIP co-activation, glucagon suppression, fat oxidation, energy expenditure
- Cagrilintide research: amylin receptor pharmacology, pancreatic beta-cell signalling, post-prandial glycaemic control, gastric emptying rate
CagriSema: The Combination Context
Novo Nordisk's CagriSema (Cagrilintide 2.4 mg + Semaglutide 2.4 mg in a fixed-dose combination) is currently in Phase 3 REDEFINE trials. Its development illustrates that amylin and GLP-1 agonism are additive in effect — a combination research approach that Retatrutide's triple mechanism does not replicate (since Retatrutide does not touch the amylin system at all).
Researchers interested in the full spectrum of metabolic peptide pharmacology may study both compound classes in parallel.
Availability from QSC
QSC supplies both Retatrutide (10 mg vials) and Cagrilintide (5 mg vials) for research use. Both are available with ≥99% HPLC purity, Janoshik COA, and domestic shipping from US, EU, UK, AU, CA, and Asia warehouses.
Source Research-Grade Retatrutide
QSC Retatrutide (RT10) — 10 mg vials, ≥99% HPLC purity, Janoshik COA on every batch. Domestic US, EU, UK, AU, CA, and Asia warehouses.
View Retatrutide at QSC →