Retatrutide — Vendor Pricing & Purity Guide
Research Overview
Retatrutide (LY-3437943) is a triple-agonist peptide developed by Eli Lilly that simultaneously activates GLP-1, GIP, and glucagon receptors. Often called "Triple G," it represents the next evolution beyond dual-agonist tirzepatide by adding glucagon receptor activation to the GLP-1/GIP backbone. This third mechanism targets fat metabolism directly, as glucagon promotes hepatic fat oxidation and energy expenditure.
The triple-agonist approach produced the most dramatic weight loss results in clinical trial history. In Phase II trials, retatrutide achieved 24.2% mean body weight reduction at the highest dose — and notably, patients had not yet plateaued at the 48-week endpoint, suggesting even greater weight loss with continued treatment. This exceeds both semaglutide and tirzepatide results.
Retatrutide is currently in Phase III clinical trials with results expected in 2025-2026. If approved, it would represent the third generation of incretin-based obesity therapeutics: GLP-1 only (semaglutide) → GLP-1/GIP (tirzepatide) → GLP-1/GIP/glucagon (retatrutide). Research-grade retatrutide is available from peptide vendors, though supply may be limited.
Key Research Findings
- •Phase II trial: 24.2% mean body weight reduction at 12 mg dose over 48 weeks — the highest weight loss from any clinical-stage drug
- •First triple-agonist (GLP-1/GIP/glucagon) to reach advanced clinical trials
- •Patients had not plateaued at 48 weeks, suggesting even greater weight loss with continued treatment
- •100% of subjects at the highest dose lost at least 5% body weight; 83% lost at least 15%
- •Glucagon receptor activation adds direct fat oxidation and energy expenditure to the incretin appetite suppression mechanism
- •Phase III trials ongoing for obesity, type 2 diabetes, and NASH
Research Dosage Protocols
Retatrutide is in Phase III clinical trials and not yet FDA-approved. In Phase II trials, the dose titration schedule reached up to 12 mg subcutaneously once weekly.
Research-grade retatrutide is supplied as lyophilized powder. Availability from research vendors may be limited as the compound is newer and more complex to synthesize.
Side effects in clinical trials were primarily gastrointestinal (nausea, diarrhea, vomiting) consistent with GLP-1 agonist class effects, plus increased heart rate attributed to the glucagon receptor component.
For research reference only. Not medical advice. Not for human consumption.
Published Research (1 studies)
- [1]Triple-hormone-receptor agonist retatrutide for obesity (Phase II)— Jastreboff et al., NEJM 2023PMID: 37351564
Links go to PubMed (NIH National Library of Medicine). PeptideVerdict is not affiliated with these studies.
Price Comparison (16 products from 7 vendors)
| Vendor | Price | Stock |
|---|---|---|
| Paradigm Peptides | $450.00 $9.00/mg 50mg lyophilized | In Stock |
| Polaris Peptides | $320.00 $9.14/mg 35mg lyophilized | In Stock |
| Paradigm Peptides | $300.00 $10.00/mg 30mg lyophilized | In Stock |
| Paradigm Peptides | $200.00 $10.00/mg 20mg lyophilized | In Stock |
| Paradigm Peptides | $100.00 $10.00/mg 10mg lyophilized | In Stock |
| Polaris Peptides | $160.00 $10.67/mg 15mg lyophilized | In Stock |
| Peptide Partners | $273.00 $11.38/mg 24mg | In Stock |
| Polaris Peptides | $140.00 $11.67/mg 12mg lyophilized | In Stock |
| Polaris Peptides | $120.00 $12.00/mg 10mg lyophilized | In Stock |
| Particle Peptides | $139.99 $14.00/mg 10mg lyophilized | In Stock |
| Polaris Peptides | $70.00 $14.00/mg 5mg lyophilized | In Stock |
| Astro Peptides | $200.00 $20.00/mg 10mg lyophilized | Out |
| NextChems | $120.00 $24.00/mg 5mg vial | In Stock |
| Astro Peptides | $1280.00 $128.00/mg 10mg lyophilized | In Stock |
| Astro Peptides | $2240.00 $224.00/mg 10mg lyophilized | In Stock |
| Skye Peptides | $109.00 lyophilized | In Stock |
Frequently Asked Questions
What is retatrutide?
Retatrutide is a triple-agonist peptide (GLP-1/GIP/glucagon) in Phase III clinical trials. It produced 24.2% weight loss in Phase II — the most of any clinical-stage obesity drug — by combining appetite suppression with direct fat oxidation.
How does retatrutide compare to tirzepatide and semaglutide?
Retatrutide (triple agonist) > tirzepatide (dual agonist) > semaglutide (single agonist) in terms of weight loss efficacy in trials. Each generation adds an additional receptor target. Retatrutide is not yet approved; the others are.
Where can I buy retatrutide for research?
Research-grade retatrutide is available from select peptide vendors. Compare pricing in the table above. Availability may be limited.