Retatrutide
GLP-1 / GIP / glucagon triple agonist. Retatrutide is investigational and not approved for any use.
Also called:retaGLP-3LY3437943
Medically reviewed by Juan Pablo Frías, MD · · DisclosureUpdated Strongest evidence: Human RCT evidence, 4 of 4
Key facts
How we verify- Class
- GLP-1 / GIP / glucagon triple agonist
- Also called
- reta, GLP-3
- Vial sizes sold
- 5 mg, 10 mg, 12 mg, 15 mg, 20 mg, 24 mg, 30 mg, 36 mg, 40 mg, 50 mg, 60 mg
- Community-reported sizes
- Half-life
- approximately 6 days
- subcutaneous, in people · Lancet 2022, PMID 36354040
- FDA status
- Not approved
- Investigational · phase 3
- WADA
- Prohibited (S0)
- In and out of competition
Everything on Retatrutide
Retatrutide guides
01DosageDoses used in published trials, the titration pattern and a units chart.02Side effectsWhat labels and studies report, and what is unknown.03CalculatorVial, water and dose to syringe units.04ResultsStudy outcomes and when they were measured.05PricePrice per mg and per week from dated listings. No vendor links.06Legal statusFDA, compounding and WADA status with dates.07How to injectSites, syringe types and hygiene, step by step.08Half-lifeWhat is measured, by route, and what is not.09StoragePowder and mixed vials: temperature and shelf life.1010 mg vialConcentration and unit tables for the 10 mg size.11For weight lossWhat research says about Retatrutide for weight loss.
Vial and dose sizes
Evidence at a glance
Human and animal counts are PubMed records from our evidence ledger (search counts, not studies we reviewed). The grade is the strongest design among the studies we summarised for that goal: a human randomized trial outweighs any number of animal studies.
| Condition | Human studies | Animal studies | Studies we summarised | Evidence grade |
|---|---|---|---|---|
| Weight loss | 71 | 7 | 13 | Human RCT evidence, 4 of 4The New England journal of medicine 2026, PMID 42814954 |
Grades follow our evidence scale. Summarised studies come from our evidence file, each quote checked against the abstract or label.
Compared with
RetatrutidevsTirzepatideGLP-1 / GIP / glucagon triple agonist next to GLP-1 / GIP dual agonist: evidence, dosing and legal status side by side.FDA approved (Mounjaro, Zepbound)Read the comparison →RetatrutidevsSemaglutideGLP-1 / GIP / glucagon triple agonist next to GLP-1 agonist: evidence, dosing and legal status side by side.FDA approved (Ozempic, Wegovy, Rybelsus)Read the comparison →RetatrutidevsCagrilintideGLP-1 / GIP / glucagon triple agonist next to amylin analog: evidence, dosing and legal status side by side.Investigational (CagriSema component)Read the comparison →RetatrutidevsMOTS-cGLP-1 / GIP / glucagon triple agonist next to mitochondrial-derived peptide: evidence, dosing and legal status side by side.PCAC voted 7–5 for 503A (Jul 2026)Read the comparison →
Common stacks
Retatrutide is often sold pre-mixed or combined with other peptides. No controlled study has tested these combinations; the pages below cover the math and what each part has been studied for.
Common questions
Is Retatrutide FDA approved?
No. Retatrutide is investigational (investigational · phase 3) and not approved for any use.
Is Retatrutide banned in sport?
Yes. Prohibited by WADA (S0), so it is prohibited at all times for tested athletes.
How much water goes in a 10 mg vial?
That choice only changes the concentration. With 2 mL, the vial is 5 mg/mL. The calculator converts any amount to syringe units. It does the math only and does not suggest a dose.
Sources
- 1Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial (Jastreboff AM et al.)New England Journal of Medicine · 2023PMID 37366315Accessed 2 Oct 2026
- 2Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity (TRIUMPH-1; Jastreboff AM et al.)New England Journal of Medicine · 2026PMID 42814954Accessed 2 Oct 2026
- 3A Phase 2 Study of Once-Weekly LY3437943 Compared With Placebo in Participants Who Have Obesity or Are Overweight With Weight-Related Comorbidities (NCT04881760; arms and posted results)ClinicalTrials.gov (U.S. National Library of Medicine) · 2021clinicaltrials.govAccessed 2 Oct 2026
- 4Warning letter to NuScience Peptides LLC (ref. 733652), 24 Aug 2026, one of five letters to research-peptide sellers issued that dayU.S. Food and Drug Administration · 2026fda.govAccessed 2 Oct 2026
- 5US search volume and year-over-year trend, Google Keyword Planner export (Jun–Aug 2026 vs 2025)Peptigraph research · 2026peptigraph.com/methodology/Accessed 1 Oct 2026
- 6World Anti-Doping Code International Standard Prohibited List 2026World Anti-Doping Agency · 2026wada-ama.orgAccessed 2 Oct 2026
- 7United States: No FDA-approved product found: Drugs@FDA (openFDA) search for active ingredient "retatrutide" returned no matches on 2 Oct 2026.U.S. Food and Drug Administration · 2026api.fda.govAccessed 2 Oct 2026
- 8World Anti-Doping Code: Prohibited List 2026World Anti-Doping Agency · 2026wada-ama.orgAccessed 2 Oct 2026
- 9Retatrutide phase 3 TRIUMPH-1 results publishedNEJM (PubMed 42814954) · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
- 10FDA warning letters to five research-peptide sellersFDA warning letter (NuScience Peptides; 1 of 5) · 2026fda.govAccessed 2 Oct 2026
- 11Eli Lilly sues six retatrutide sellersEli Lilly (press release) · 2026investor.lilly.comAccessed 2 Oct 2026
- 12Seven FDA warning letters to online sellers of GLP-1 productsFDA warning letter (Gram Peptides; 1 of 7) · 2026fda.govAccessed 2 Oct 2026
- 13LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial.Lancet (London, England) · 2022PMID 36354040Accessed 2 Oct 2026
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