Retatrutide — The Core
The triple GLP-1/GIP/Glucagon agonist at the center of the Clav stack. Phase 2: −28.7% body weight at 48 weeks.
Mechanism of Action
GLP-1R Appetite Suppression
GLP-1 receptor activation in the hypothalamus suppresses appetite, slows gastric emptying, and extends satiety. This is the shared mechanism with semaglutide — the foundation of all GLP peptides.
GcgR Fat Oxidation
Glucagon receptor engagement drives hepatic beta-oxidation and brown adipose thermogenesis — active fat burning mechanisms absent in semaglutide and tirzepatide. This is why Retatrutide's Phase 2 data (−28.7%) far exceeds dual agonists.
GIPR Insulin Sensitization
GIP receptor agonism enhances peripheral insulin sensitivity and synergistically potentiates GLP-1 receptor signaling — explaining the additive benefit of dual and triple agonists over GLP-1 alone.
Products in This Layer
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GLP-3 R 15mg
Retatrutide (GLP-3 R) 15mg — the standard Clav stack supply. Clavicular's primary fat loss compound. Triple GLP-1/GIP/Glucagon receptor agonist. Phase 2 data: −28.7% body weight at 48 weeks. Most popular vial size. >98% purity.
CAS: 2381609-35-2
GLP-3 R 10mg
Retatrutide (GLP-3 R) 10mg — starter supply for triple GLP-1/GIP/Glucagon receptor agonist research. The entry-level Clav stack compound. Phase 2: −28.7% body weight at 48 weeks. >98% purity, HPLC tested, lyophilized.
CAS: 2381609-35-2
Retatrutide: The Triple-Agonist Core
Retatrutide is the most potent GLP peptide in clinical research. Unlike semaglutide (GLP-1 only) or tirzepatide (GLP-1 + GIP), Retatrutide activates three receptors simultaneously:
- GLP-1R — appetite suppression, satiety, insulin secretion
- GIPR — enhanced insulin sensitivity, adipocyte metabolism
- GcgR — hepatic fat oxidation, brown adipose thermogenesis
Phase 2 Trial Results
| Dose | 24-week loss | 48-week loss |
| 4mg/week | −17.5% | — | ||||
| 8mg/week | −24.2% | −28.7% | The 48-week trajectory had not plateaued — suggesting continued loss with longer protocols. vs Semaglutide and Tirzepatide | Compound | Receptors | Best Phase Result |
| Semaglutide | GLP-1 | −14.9% (STEP-1) |
| Tirzepatide | GLP-1 + GIP | −20.9% (SURMOUNT-1) |
| Retatrutide | GLP-1 + GIP + GcgR | −28.7% (Phase 2) |
Why the Clav Stack Uses Retatrutide
Clavicular chose Retatrutide specifically for the glucagon receptor engagement — the third mechanism that sets it apart. The data-driven argument: if you're going to run a GLP protocol for looksmaxxing, run the one with the most receptor coverage.
Frequently Asked Questions
What is Retatrutide?
Retatrutide (GLP-3 R) is a triple GLP-1/GIP/Glucagon receptor agonist — the most advanced GLP compound in clinical research. Phase 2 trial showed −28.7% body weight reduction at 48 weeks, the highest result ever recorded for a GLP compound.
How is Retatrutide different from tirzepatide?
Tirzepatide activates GLP-1 and GIP receptors. Retatrutide adds the Glucagon receptor — which drives hepatic fat oxidation and brown adipose thermogenesis, raising resting metabolic rate. This is the mechanism behind Retatrutide's ~8 percentage point advantage over tirzepatide in fat loss data.
What vial size should I buy?
GLP-3 R 15mg is the standard Clav stack supply. The 30mg is the best value per mg for extended protocols. The 60mg is for bulk/long-term research.
Related Research Articles
What Is the Clavicular Peptide Stack? Every Compound Explained
The complete breakdown of Clavicular's viral looksmaxxing peptide protocol — Retatrutide, BPC-157, GHK-CU, and SNAP-8.
Retatrutide vs Tirzepatide vs Semaglutide: Why Clav Chose Triple-Agonist
Data comparison of all three GLP generations. Why the Clavicular stack uses Retatrutide over tirzepatide and semaglutide.
Why BPC-157 Is Non-Negotiable When Running Retatrutide
The gut science behind running BPC-157 alongside every GLP protocol. What GLP peptides do to your GI tract and how BPC-157 addresses it.
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