Retatrutide
Investigational triple-agonist peptide (GLP-1/GIP/glucagon) developed by Eli Lilly, researched for metabolic regulation, weight management, and glucose control.
Also known as LY3437943, LY-3437943
Peptigrity has 1432 lab tests of retatrutide on file from 305 shops and 27 labs; the newest is from . Average HPLC purity is 99.68% across the 1428 results that report it, and 98.3% of results are at or above 99%. 1424 results compare the measured amount with the label (median 109.5% of label); 323 report endotoxin. 29 shops publish prices: $0.128 to $21.00 per mg, median $6.50. Peptigrity publishes measurements, not dosing advice.
From Peptigrity records · figures updated · Cite these figures
Lab test results
| Tested | Shop | Lab | Purity | Measured vs label | Endotoxin | Record |
|---|---|---|---|---|---|---|
| Shop withheld | Janoshik Labs | — | not reported | Reported | 10-2026-H08 | |
| SH Labz Peptides | Janoshik Labs | 99.91% | 16.21 / 15 mg 108% of label | — | SH-RT15-112026 | |
| Shop withheld | Freedom Diagnostics | 99.81% | 32.27 / 30 mg 108% of label | — | RT-30-001 | |
| Shop withheld | Uzorak | 99.74% | 54.13 / 60 mg 90% of label | Reported | rt60 | |
| Shop withheld | Uzorak | 99.60% | 10.03 / 10 mg 100% of label | — | XX150926 | |
| Shop withheld | liquilabs | 99.70% | 9.47 / 10 mg 95% of label | Reported | RTX3-10-261005-02 | |
| Shop withheld | Freedom Diagnostics | 99.74% | 11.42 / 10 mg 114% of label | — | RT-10-004 | |
| SF Bay Area Peptides | Freedom Diagnostics | 99.86% | 24.89 / 20 mg 124% of label | — | 10565 | |
| Shop withheld | Uzorak | 98.49% | 66.9 / 60 mg 112% of label | — | RT60-20260929-01 | |
| Shop withheld | KMD Analytical | 99.99% | 19.75 / 20 mg 99% of label | — | SD-3XAG-20-01 | |
| Shop withheld | Janoshik Labs | 99.82% | 11.76 / 10 mg 118% of label | — | RT10-2026-09-B | |
| Shop withheld | — | 99.10% | 15.6 / 15 mg 104% of label | Pass | RT15-7741 |
Shops with a retatrutide test since
152 shops. A shop is listed when a third-party lab published a test of its retatrutide in the last six months; the newest result is shown, as the lab reported it. Ordered by date, nothing else. Only shops that have chosen to appear are listed; the count includes every shop.
| Shop | Newest test | Result | Retatrutide tests | Warehouse | Reviews |
|---|---|---|---|---|---|
| SH Labz PeptidesClaimedTests on file | Lot SH-RT15-112026 · Janoshik Labs | 99.91% | 3 | 🇦🇪 United Arab Emirates | No reviews yet |
| SF Bay Area PeptidesClaimedTests on file | Lot 10565 · Freedom Diagnostics | 99.86% | 1 | 🇺🇸 United States | No reviews yet |
| Purely PeptidesClaimedTests on file | Lot xbhwgh9 · Krause Analytical | 99.90% | 4 | 🇺🇸 United States | 1 · 5.0 |
| PeptuviaClaimedTests on file | View record · Freedom Diagnostics | 99.78% | 7 | 🇺🇸 United States · 🇫🇷 France · 🇦🇺 Australia · 🇬🇧 United Kingdom · 🇨🇦 Canada · 🇨🇳 China · 🇳🇱 Netherlands | 20 · 5.0 |
| Alchemy Gold ResearchClaimedTests on file | Lot 000001 · Janoshik Labs | 99.67% | 2 | 🇺🇸 United States | 3 · 5.0 |
| 10 Bottle ValueClaimedTests on file | Lot WC1 · Krause Analytical | 99.90% | 1 | 🇺🇸 United States | 4 · 5.0 |
| Offline PeptidesClaimedTests on file | Lot OP-RT50-0726 · Freedom Diagnostics | 99.96% | 1 | 🇺🇸 United States | No reviews yet |
Shops listing Retatrutide
Compare prices from 29 shops →What is Retatrutide?
Retatrutide, also designated LY3437943, is a 39-amino-acid investigational triple-receptor agonist activating GLP-1, GIP, and glucagon receptors. Developed by Eli Lilly and currently in the Phase 3 TRIUMPH program, retatrutide is not approved by the FDA or any other regulator for any indication and is supplied strictly for research use only. The lab test table and shop directory above show Peptigrity's independent verification data for retatrutide, updated continuously as new HPLC tests are submitted.
What is retatrutide and why does the triple-agonist mechanism matter?
Retatrutide is the first triple GLP-1 / GIP / glucagon receptor agonist to reach Phase 3 clinical trials, distinguishing it from semaglutide (single GLP-1 agonist) and tirzepatide (dual GLP-1/GIP). The glucagon component is the new variable — in human trials, it appears to drive direct energy expenditure and hepatic fat clearance, mechanisms unavailable to single or dual agonists. The full receptor pharmacology, signaling pathways, and TRIUMPH-program design are covered in our retatrutide triple-agonist science guide.
What does the Phase 3 evidence show?
Retatrutide now has peer-reviewed Phase 3 obesity data. In TRIUMPH-1 (New England Journal of Medicine, September 2026; 2,339 adults with obesity or overweight), 12 mg weekly reduced body weight by 25.0% at 80 weeks versus 3.9% on placebo. In TRIUMPH-2 (The Lancet, September 2026; 1,152 adults with type 2 diabetes and obesity or overweight), 12 mg reduced weight by 18.8% versus 5.1%. Both figures count everyone randomized, including people who stopped treatment.
Lilly's headline figures are higher because they use the efficacy estimand, which estimates the effect had everyone stayed on treatment: 28.3% versus 2.2% for TRIUMPH-1, and 20.8% versus 4.0% for TRIUMPH-2, where HbA1c also fell 1.5 percentage points on 12 mg versus 0.2 on placebo, from a baseline of 7.7%. Lilly also reports 30.3% at 104 weeks for TRIUMPH-1 participants with a BMI of 35 or more who continued on 12 mg. Two obesity readouts are still company topline, not yet peer-reviewed: TRIUMPH-3 (severe obesity with established cardiovascular disease; 22.6% at 80 weeks) and TRIUMPH-4 (obesity or overweight with knee osteoarthritis; 28.7% at 68 weeks, with reduced knee pain), both on the efficacy estimand. The first published Phase 3 trial, TRANSCEND-T2D-1 (The Lancet, June 2026), lowered HbA1c by 1.94 percentage points on 12 mg versus 0.81 on placebo, and body weight by 15.3% versus 2.6%, over 40 weeks in adults with type 2 diabetes. Before 2026, the only published obesity data came from Phase 2: 24.2% at 48 weeks on 12 mg, in a trial of 338 participants across all doses.
Sources: Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial, Jastreboff A.M. et al., N Engl J Med, 2023; Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity, Jastreboff A.M., Kaplan L.M., Davies M.J., Wilding J.P.H., et al., N Engl J Med, 2026; Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial, Bellido V., le Roux C.W., Ekinci E.I., Bjornstad P., Frias J.P., et al., Lancet, 2026; Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial, Bajaj H.S., Welch M., Shah P., et al., Lancet, 2026 · Evidence level: human RCT — published Phase 2 (obesity) and Phase 3 (TRIUMPH-1, TRIUMPH-2, TRANSCEND-T2D-1); TRIUMPH-3 and TRIUMPH-4 are company topline, not yet peer-reviewed; efficacy-estimand and 104-week figures as reported by Lilly
| Trial | Population | Participants | Length | Weight change, 12 mg vs placebo | Status |
|---|---|---|---|---|---|
| TRIUMPH-1 | Obesity or overweight | 2,339 | 80 weeks | −25.0% vs −3.9% (TR) · −28.3% vs −2.2% (efficacy) | Published, NEJM, Sep 2026 |
| TRIUMPH-2 | Type 2 diabetes with obesity or overweight | 1,152 | 80 weeks | −18.8% vs −5.1% (TR) · −20.8% vs −4.0% (efficacy) | Published, The Lancet, Sep 2026 |
| TRANSCEND-T2D-1 | Type 2 diabetes on diet and exercise alone | 537 | 40 weeks | −15.3% vs −2.6% (TR); HbA1c −1.94 vs −0.81 points | Published, The Lancet, Jun 2026 |
| TRIUMPH-3 | Severe obesity (BMI ≥35) with cardiovascular disease | 1,949 | 80 weeks | −22.6% vs −3.2% (efficacy) | Company topline, Jul 2026 |
| TRIUMPH-4 | Obesity or overweight with knee osteoarthritis | 445 | 68 weeks | −23.7% vs −4.6% (TR) · −28.7% vs −2.1% (efficacy) | Company topline, Dec 2025 |
TR = treatment-regimen estimand: everyone randomized counts, including people who stopped treatment. Efficacy = Lilly's estimate of the effect had everyone stayed on treatment.
How does retatrutide compare to semaglutide and tirzepatide?
Across separate Phase 3 trials, retatrutide has reported the largest average weight loss of the three, but no head-to-head result exists yet. Counting everyone randomized, retatrutide 12 mg reached 25.0% at 80 weeks in TRIUMPH-1, tirzepatide 15 mg 20.9% at 72 weeks in SURMOUNT-1, and semaglutide 2.4 mg 14.9% at 68 weeks in STEP 1. The trials ran separately and for different lengths, so the gap is indicative rather than a direct comparison. TRIUMPH-5, a direct retatrutide-versus-tirzepatide trial (NCT06662383), had not reported results as of October 2026.
Sources: Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity, Jastreboff A.M., Kaplan L.M., Davies M.J., Wilding J.P.H., et al., N Engl J Med, 2026; Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1), Jastreboff A.M. et al., N Engl J Med, 2022; Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1), Wilding J.P.H. et al., N Engl J Med, 2021
| Compound | Mechanism | Phase 3 weight loss | Regulatory status |
|---|---|---|---|
| Retatrutide | GLP-1 + GIP + glucagon (triple) | 25.0% — TRIUMPH-1, 80 wks, 12 mg | Investigational, no approvals |
| Tirzepatide | GLP-1 + GIP (dual) | 20.9% — SURMOUNT-1, 72 wks, 15 mg | FDA-approved |
| Semaglutide | GLP-1 (single) | 14.9% — STEP 1, 68 wks, 2.4 mg | FDA-approved (Ozempic/Wegovy) |
Each figure counts everyone randomized, whether or not they stayed on treatment (treatment-regimen estimand for Lilly's trials, treatment-policy for STEP 1). Lilly's higher headline numbers for retatrutide, 28.3% in TRIUMPH-1 and 28.7% in TRIUMPH-4, use the efficacy estimand and do not compare with these.
What are the documented side effects of retatrutide?
Retatrutide's most common side effects are dose-related gastrointestinal events — nausea, diarrhoea, constipation and vomiting — mostly mild to moderate in severity. In the published TRIUMPH-2 trial, nausea affected 28.0% of participants on 12 mg versus 8.0% on placebo. Retatrutide also raised the rate of dysesthesia, an abnormal skin sensation, in every Phase 3 trial reported so far: 4.5–7.3% across doses in TRIUMPH-2 versus 0.7% on placebo, and 20.9% on 12 mg in TRIUMPH-4 (company topline).
Stopping treatment for adverse events generally rose with dose and was highest in TRIUMPH-4 (company topline): 18.2% on 12 mg versus 4.0% on placebo. Our retatrutide side effects guide covers the Phase 2 safety findings and side-effect questions specific to research-grade vials, such as fill variance.
Sources: Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial, Jastreboff A.M. et al., N Engl J Med, 2023; Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity, Jastreboff A.M., Kaplan L.M., Davies M.J., Wilding J.P.H., et al., N Engl J Med, 2026; Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial, Bellido V., le Roux C.W., Ekinci E.I., Bjornstad P., Frias J.P., et al., Lancet, 2026; Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial, Bajaj H.S., Welch M., Shah P., et al., Lancet, 2026 · Evidence level: human RCT (Phase 2 and Phase 3); per-trial rates as reported by Lilly; TRIUMPH-3 and TRIUMPH-4 are company topline, not yet peer-reviewed
| Trial | Doses | Dysesthesia, retatrutide vs placebo | Stopped for adverse events, retatrutide vs placebo | Data |
|---|---|---|---|---|
| TRIUMPH-1 | 4 / 9 / 12 mg | 5.1% / 12.3% / 12.5% vs 0.9% | 4.1% / 6.9% / 11.3% vs 4.9% | Lilly-reported; trial published in NEJM |
| TRIUMPH-2 | 4 / 9 / 12 mg | 4.5% / 5.6% / 7.3% vs 0.7% | 3.8% / 11.6% / 7.7% vs 4.9% | Lilly-reported; trial published in The Lancet |
| TRANSCEND-T2D-1 | 4 / 9 / 12 mg | 4.5% / 2.3% / 4.4% vs 0.0% | 2.2% / 4.5% / 5.1% vs 0.0% | Lilly-reported; trial published in The Lancet |
| TRIUMPH-3 | 9 / 12 mg | 6.4% / 6.4% vs 1.3% | 9.8% / 13.5% vs 4.8% | Company topline |
| TRIUMPH-4 | 9 / 12 mg | 8.8% / 20.9% vs 0.7% | 12.2% / 18.2% vs 4.0% | Company topline |
What is the regulatory status of retatrutide?
Retatrutide is not approved for any indication, anywhere in the world, as of October 2026. Unlike semaglutide and tirzepatide, it was never on the FDA drug-shortage list and never had a legal compounding pathway — there is no pharmacy-compounded reference product, only research-grade material. Eli Lilly has said it plans to submit a Biologics License Application for retatrutide to the FDA in the first quarter of 2027. Retatrutide is sold strictly as a research-use-only compound by third-party laboratories, with no approved prescription pathway. Country-specific import rules apply — see our peptide regulatory status by country guide.
Source: Retatrutide TRIUMPH-2 results and planned FDA Biologics License Application (press release, 29 Sep 2026), via Eli Lilly and Company
Why does retatrutide vendor verification matter more than for older GLP-1s?
Retatrutide's narrower manufacturing base, higher market price, and absence of an FDA-approved reference product create wider purity variance and stronger economic incentive for underdosing than older GLP-1 compounds. The triple-agonist synthesis adds complexity that fewer laboratories have optimized at scale. Independent HPLC purity testing and mass spectrometry identity confirmation (expected molecular weight 4,731.4 Da) are the only meaningful purity signals a research-grade vendor can provide. Learn how to interpret these in our how-to-test-peptides hub and the reading peptide lab test results guide.
Source: Retatrutide — PubChem compound record (CID 171390338, MW 4,731.4 Da), PubChem (NIH), 2024
How does Peptigrity verify retatrutide vendors?
Peptigrity collects independent third-party Certificates of Analysis for retatrutide from shops' official channels and verifies each for authenticity before publishing. Because shops choose which COAs to publish, results reflect the batches shops have made public rather than every production batch — a selection bias we state openly. A community-funded Testing Grant to purchase and test vials anonymously is in development. The lab test table above this section shows the full cross-shop dataset, sortable by date, purity, and labeled-vs-tested quantity. Tests are sourced from named labs including Janoshik Analytical, Freedom Diagnostics, Chromate, Trust Pointe Analytics, and Krause Analytical. Our verification methodology — including the trust score weighting of reviews (50%) and lab purity (50%) — is documented in how we calculate trust scores.
Frequently asked questions
How can I verify a retatrutide vendor is selling real product?
The only reliable purity signal is an independent third-party HPLC certificate of analysis from a lab the vendor does not own or pay — not a vendor-published COA on vendor letterhead. Peptigrity publishes independent retatrutide test results from independent labs in the table above. For COA interpretation, see red flags in peptide certificates of analysis.
Is retatrutide legal to purchase?
Not for personal use: no regulator has approved retatrutide as of October 2026, so there is no legal route to buy it to take yourself. Lilly's September 2026 EASD announcement says it is legally available only to participants in Lilly's clinical trials. Shops sell it only as a research-use-only chemical for laboratory work, not for human consumption. In the US, FDA's personal importation guidance says that in most circumstances it is illegal for individuals to import drugs for personal use. Rules on import and possession vary by country.
Sources: Lilly to present new data on Foundayo, retatrutide, and eloraTZP at EASD 2026, Eli Lilly and Company, via PR Newswire; Personal Importation, via U.S. Food and Drug Administration
When will retatrutide be FDA-approved?
No FDA approval has been granted as of October 2026, and Lilly has not yet filed. Eli Lilly has reported Phase 3 results from TRIUMPH-1 to TRIUMPH-4 and TRANSCEND-T2D-1, three of them now peer-reviewed, and says it plans to submit a Biologics License Application to the FDA in the first quarter of 2027. Approval timing will depend on FDA's review of that filing. Track regulatory developments in FDA peptide regulation 2025–2026: the complete timeline.
Why is retatrutide more expensive than semaglutide or tirzepatide?
Three factors: synthesis complexity (triple-agonist modification requires additional steps), narrower manufacturing base (fewer labs have optimized production at scale), and demand outpacing supply since the Phase 2 publication. Expect prices to fall as additional manufacturers come online post-TRIUMPH approval. Current research-grade market range is broken down in how much do peptides cost.
Does Peptigrity recommend a retatrutide dose?
No. Retatrutide is not approved for human consumption and Peptigrity is an independent review platform, not a medical authority. The doses tested in Phase 3 (4 mg, 9 mg, 12 mg weekly) were administered under clinical supervision with full monitoring — translating these into a self-administration protocol is medical practice. Anyone considering use of investigational compounds should consult a licensed physician.
How does retatrutide compare to other triple agonists in development?
Retatrutide is currently the only Phase 3 triple agonist with reported weight-loss data. Among dual GLP-1/glucagon agonists, survodutide reported Phase 3 weight-loss results in 2026 and remains investigational, and mazdutide has been approved in China for weight management since June 2025.
This section is for educational and informational purposes only and does not constitute medical advice. Retatrutide is an investigational compound not approved by the FDA or any other regulator for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.
Retatrutide and other weight loss & metabolic peptides
| Compound | Mechanism | Avg purity | Tests | Shops |
|---|---|---|---|---|
| Retatrutide This page | GLP-1 / GIP / Glucagon triple-agonist | 99.7% | 1,432 | 424 |
| Tirzepatide | GLP-1 / GIP dual-agonist | 99.8% | 1,065 | 374 |
| MOTS-C | Mitochondrial-derived metabolic peptide | 99.4% | 612 | 482 |
| Semaglutide | GLP-1 receptor agonist | 99.7% | 455 | 298 |
| Cagrilintide | Long-acting amylin receptor agonist | 99.6% | 284 | 296 |
| 5-Amino-1MQ | NNMT inhibitor (small molecule) | 99.6% | 190 | 355 |
| AOD-9604 | Direct adipocyte lipolysis (GH 176–191 analog) | 99.3% | 150 | 295 |
| HGH Fragment 176–191 | HGH fragment for lipolysis | 99.0% | 62 | 143 |
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