Phase 1 through Phase 3 research across several metabolic outcomes.
Why this matters
Research depth describes how large and mature the overall record is. It does not tell you whether the results were positive.
Compound library
GIP / GLP-1 / glucagon triple receptor agonist
Retatrutide
Investigational
Retatrutide is an investigational once-weekly triple agonist being studied for obesity, type 2 diabetes, and related complications. Human trials show substantial group-level effects on weight and metabolic outcomes, but it is not an approved medicine.
Controlled human studyMechanistic rationaleRegistered trial — no resultsNo direct evidence located
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Publicly anonymous by default. Your account keeps reports editable and helps reduce duplicate submissions.Educational research record—not medical advice. Evidence reviewed through July 24, 2026. Peer-reviewed findings, regulatory labeling, sponsor-reported topline results, and unreported registered trials are labeled separately.
Research at a glance
Retatrutide in 60 seconds
Depth and confidence summarize the research record—not effectiveness, safety, or a recommendation.
Controlled trials are consistent, while long-term outcomes and full pivotal reporting remain incomplete.
Why this matters
Confidence describes how reliable and consistent the conclusions are. It can be high for one outcome and low for another.
Why this matters
The strongest evidence type shows what the best-supported conclusions are actually based on.
Why this matters
Human findings are more directly relevant than animal or laboratory results, but they still apply only to the populations and outcomes studied.
Route-specific record
What changes by administration method
Route studiedSubcutaneous injection in published trials
Schedules studiedOnce weekly in controlled human research
Amounts studied0.5–12 mg once weekly across published human trials; individual studies used selected arms and different escalation schemes
Why this matters
These are exposures used in cited research for a specific route and population—not a suggested amount.
Half-lifeApproximately 6 days in early human pharmacokinetic research
Why this matters
Half-life describes how long it takes the measured amount in the body to fall by half. It is not a dosing recommendation.
Route evidencePeer-reviewed Phase 1b, Phase 2, and Phase 3 evidence
Why this matters
Evidence can change by administration method. Findings from one route should not automatically be applied to another.
Evidence boundary: The 0.5 mg arm came from Phase 2 type 2 diabetes research; the obesity and later Phase 3 programs used different selected doses. This combined research span is not one recommended escalation protocol. Amounts shown describe cited research exposure—not a dosage recommendation.
Practical starting point
Why people research it
Common goals and questions—not recommendations or promises of benefit.
- Weight lossSupported by human studies
- Reduced appetite and feeling fullerMechanistically plausible
- Blood-sugar controlSupported by human studies
- Fatty-liver reductionEarly human evidence
- Heart and kidney outcomesCurrently being studied
The overview, studies, and source ledger below explain what supports each label—and where the evidence stops.
The short version
What is Retatrutide?
Retatrutide is an investigational once-weekly triple agonist being studied for obesity, type 2 diabetes, and related complications. Human trials show substantial group-level effects on weight and metabolic outcomes, but it is not an approved medicine.
Phase 3Current development stage
5Peer-reviewed sources
3Topline source releases
How it is designed to work
- GLP-1 receptor agonism
- GIP receptor agonism
- Glucagon receptor agonism
Studied research areas
Evidence checked through July 24, 2026
Includes Lilly’s July 23 TRIUMPH-2 and TRIUMPH-3 topline release. Sponsor-reported findings remain separated from the full peer-reviewed Phase 3 report in The Lancet.
What the evidence says
What we know—and what we’re still learning
What we know
A 537-participant, randomized, double-blind Phase 3 trial in type 2 diabetes was published in The Lancet in June 2026. Multiple larger obesity Phase 3 trials have positive topline results, but full peer-reviewed reports were not yet located at the cutoff.
Why this matters
This is the strongest supported conclusion in the current human evidence—not a summary of every claim made about the compound.
What we’re still learning
Long-term cardiovascular, renal, and rare-event safety; durability after discontinuation; and full peer-reviewed reporting from the pivotal obesity program.
Why this matters
Keeping the main uncertainty visible prevents an early or promising finding from looking more settled than it is.
The evidence story
How the research changed over time
Importance shows how much an item changes the evidence story. Quality shows how much confidence the design deserves. A strong negative study can score highly on both.
Why this matters
Importance and quality answer different questions. A rigorous study can be highly important even when it challenges a popular claim.
TRIUMPH-2 and TRIUMPH-3 Phase 3 topline results
On July 23, 2026, Lilly reported up to 20.8% mean weight loss in TRIUMPH-2 and up to 22.6% in TRIUMPH-3 at 80 weeks.
80 weeks
TRANSCEND-T2D-1: efficacy and safety of retatrutide in type 2 diabetes
Mean HbA1c fell 1.69–1.94 percentage points with retatrutide versus 0.81 with placebo. Mean body-weight change was −11.5% to −15.3% versus −2.6% with placebo.
n = 53740 weeks
TRIUMPH-1 Phase 3 topline results
Sponsor-reported efficacy-estimand results showed mean weight changes of −19.0%, −25.9%, and −28.3% across retatrutide doses versus −2.2% with placebo at week 80.
n = 233980 weeks; selected extension participants to 104 weeks
TRIUMPH-4 Phase 3 topline results
Sponsor-reported results showed mean weight change up to −28.7% and mean WOMAC pain-score reduction up to 4.5 points at 68 weeks.
n = 44568 weeks
Retatrutide for metabolic dysfunction-associated steatotic liver disease
At week 24, mean relative liver-fat change was −42.9%, −57.0%, −81.4%, and −82.4% across the four retatrutide groups versus +0.3% with placebo.
n = 9848 weeks; primary liver-fat analysis at 24 weeks
Administration and handling
What official research does—and does not—provide
Study administration, not guidance
Published trials used once-weekly subcutaneous administration with protocol-defined arms and escalation schedules. These are descriptions of research protocols—not a recommended dose, route, or schedule.
Reconstitution, storage, and stability
No public, regulator-approved consumer storage or stability instructions were identified. Retatrutide remains investigational, and trial material is prepared and controlled by the sponsor. Peptide Relay does not convert vendor claims into official storage guidance.
Primary-source ledger
Trace every major statement
Sponsor-reported topline
Sponsor-reported toplineTRIUMPH-2 and TRIUMPH-3 Phase 3 topline results
2026-07-23 · NCT05929079; NCT05882045
Official status
Official statusWhat to know about retatrutide
2026-07-01
Peer reviewed
Peer reviewedTRANSCEND-T2D-1: efficacy and safety of retatrutide in type 2 diabetes
2026-06-06 · PMID 42250575 · NCT06354660 · DOI 10.1016/S0140-6736(26)00967-0
Sponsor-reported topline
Sponsor-reported toplineTRIUMPH-1 Phase 3 topline results
2026-05-21 · NCT05929066
Sponsor-reported topline
Sponsor-reported toplineTRIUMPH-4 Phase 3 topline results
2025-12-11 · NCT05931367
The sponsor release prints NCT05869903, which is an orforglipron study. ClinicalTrials.gov and Lilly's trial page identify TRIUMPH-4 as NCT05931367.
Peer reviewed
Peer reviewedRetatrutide for metabolic dysfunction-associated steatotic liver disease
2024-06-10 · PMID 38858523 · NCT04881760 · DOI 10.1038/s41591-024-03018-2
Peer reviewed
Peer reviewedRetatrutide for people with type 2 diabetes: a phase 2 trial
2023-06-26 · PMID 37385280 · NCT04867785 · DOI 10.1016/S0140-6736(23)01053-X
Peer reviewed
Peer reviewedTriple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial
2023-06-26 · PMID 37366315 · NCT04881760 · DOI 10.1056/NEJMoa2301972
Peer reviewed
Peer reviewedLY3437943 in people with type 2 diabetes: a phase 1b multiple-ascending-dose trial
2022-11-26 · PMID 36354040 · NCT04143802 · DOI 10.1016/S0140-6736(22)02033-5