For informational and research purposes only. Not medical advice. Content is aggregated from public sources. Always consult a qualified healthcare provider.

Retatrutide

GLP-1

Also known as: LY3437943, Triple G, GIP/GLP-1/Glucagon Receptor Agonist

Retatrutide is an investigational compound. It is not FDA-approved. This profile is for research and educational purposes only.

Overview

Retatrutide is an investigational triple agonist targeting GIP, GLP-1, and glucagon receptors simultaneously. Phase 2 trials showed weight reductions exceeding 24% over 48 weeks — among the highest reported for any peptide compound in clinical study.

Research Summary

In a Phase 2 Eli Lilly trial (NEJM, 2023), retatrutide produced dose-dependent weight loss of up to 24.2% body weight over 48 weeks. The triple receptor mechanism appears to enhance energy expenditure via glucagon signaling while simultaneously reducing appetite via GLP-1 and GIP pathways. Metabolic markers including fasting glucose, triglycerides, and blood pressure all improved significantly.

Dosing Range

low

2mg

moderate

4mg

high

8mg

Units: mg · Frequency: once weekly

Dosing ranges are aggregated from preclinical research and community protocols. Not medical dosing guidance.

Administration Routes

Subcutaneous injection (weekly)

Reconstitution Notes

Typically supplied as a lyophilized powder. Reconstitute with bacteriostatic water. Store at 2–8°C after reconstitution. Do not freeze reconstituted solution.
Step-by-step reconstitution guide →

Reported Side Effects

  • Nausea (most common, dose-dependent)
  • Vomiting
  • Diarrhea
  • Decreased appetite
  • Injection site reactions
  • Constipation

Research Papers

Retatrutide Phase 2 Obesity Trial (NEJM 2023)
New England Journal of Medicine2023

Community Experiences

Aggregated from public forums. Anecdotal — not clinical evidence.

r/Peptides

Community threads on retatrutide protocols, sourcing, and results.

View original thread

Overview

Retatrutide (LY3437943) is a triple receptor agonist developed by Eli Lilly targeting GIP (glucose-dependent insulinotropic polypeptide), GLP-1, and glucagon receptors simultaneously. It represents a significant advancement beyond dual agonists like tirzepatide.

Mechanism

The triple mechanism differentiates retatrutide from existing GLP-1 drugs:

  • GLP-1: Reduces appetite, slows gastric emptying
  • GIP: Enhances insulin sensitivity, additive appetite suppression
  • Glucagon: Increases energy expenditure, drives additional fat oxidation

The glucagon component is what distinguishes retatrutide — it pushes thermogenesis beyond what GLP-1/GIP alone can achieve.

Clinical Data

Phase 2 results published in the New England Journal of Medicine (2023) showed:

  • 24.2% mean weight loss at the highest dose (12mg) over 48 weeks
  • Dose-dependent response across 1mg, 2mg, 4mg, 8mg, and 12mg cohorts
  • Improvements in cardiometabolic markers across all doses

Phase 3 trials are ongoing as of 2024.

Research Notes

All published human data comes from industry-sponsored trials. Retatrutide has not been independently approved or widely studied outside Lilly's clinical program. Community protocols are extrapolated from Phase 2 dosing schedules.

Want to calculate your dose? Use the dosing calculator →