Carl read the papersWhat it actually is
Retatrutide (Eli Lilly’s “triple-G”) hits three metabolic receptors at once — GLP-1 and GIP (like tirzepatide) plus glucagon, which adds an energy-expenditure and fat-burning angle on top of appetite suppression.
In phase-2 trials it produced the largest average weight loss of any incretin drug so far (~24% at the top dose). It’s still investigational — not yet approved — but it’s the most-hyped fat-loss peptide in the community right now.
How it’s thought to work
- Triple agonism — GLP-1 + GIP + glucagon receptors together.
- Appetite + satiety — strong hunger reduction like the GLP-class.
- Glucagon angle — adds energy expenditure / fat mobilisation the others don’t.
- Weekly kinetics — long half-life, once-weekly dosing.
What the research says
Phase-2 human trials show record weight loss (~24%); phase-3 ongoing. Strong, recent human data — but not yet approved, so it’s investigational.
- Largest average weight loss of any incretin so far.
- Metabolic / fatty-liver and diabetes research.
- The community’s current ‘most wanted’ fat-loss peptide.
Reported protocols
These are the doses the peptide community actually reports running (Reddit & forums), alongside published research — logged for education, not as a recommendation to use.
| Parameter | Commonly reported range |
|---|---|
| Community dose | Start 1–2 mg/week, titrate to 4–12 mg (microdose 0.5–1 mg common) |
| Frequency | Once weekly |
| Route | Subcutaneous |
| Titration | Even slower than tirz — glucagon can bump heart rate; hold steps 4+ weeks |
| Community tip | Watch resting heart rate & hydration; titrate gently, don’t chase the top dose |
Common use cases
| Goal | Community protocol notes |
|---|---|
| Aggressive fat loss | 1–2 → 4–12 mg/wk, slow titration |
| With MOTS-c (Recomp) | metabolic support on a hard cut |
| (Caution) | monitor heart rate & glucose |
Mixing it (reconstitution)
Freeze-dried peptides must be reconstituted with bacteriostatic water before they can be measured. Carl’s calculator turns “mg in the vial + ml of water + target dose” into “units on the syringe” — and tells you how long the vial lasts.
→ Open the Reconstitution Calculator
Injection & handling
SubQ once weekly (rotate sites). Titrate VERY slowly — 1–2 mg to start, up to 4–12 mg — because the glucagon action can raise heart rate; watch resting HR and hydration. Unapproved/grey-market; store per source guidance.
Stacks it appears in
- The Recomp — Retatrutide + MOTS-c — aggressive cut with metabolic support.
- The Deep Cut — Retatrutide + Tesamorelin — fat loss plus visceral-fat and GH support to protect muscle.
