Where can I find TRIUMPH trial results?

Trials are registered on ClinicalTrials.gov, with topline results issued by Lilly and peer-reviewed publication following database posting.

Have all the TRIUMPH trials reported?

No. The pivotal trials have reported, but further readouts including maintenance-dosing studies were still expected across 2026.

Does TRIUMPH mean retatrutide is approved?

No. It remains investigational everywhere; an FDA filing was signalled for Q1 2027.

What Is the TRIUMPH Trial Programme?

The short answer

TRIUMPH is Eli Lilly's Phase 3 clinical trial programme for retatrutide, enrolling more than 5,800 participants across obesity, type 2 diabetes and cardiovascular populations. TRIUMPH-4 reported first in December 2025, TRIUMPH-1 in May 2026 and TRIUMPH-2 and -3 in July 2026. All pivotal trials reported so far have met their primary endpoints.

Key facts

Sponsor: Eli Lilly and Company
Phase: Phase 3
Total enrolment: More than 5,800 participants
First readout: TRIUMPH-4, December 2025
Pivotal obesity trial: TRIUMPH-1 (NCT05929066), May 2026
Headline result: 28.3% mean reduction at 80 weeks (12 mg)
Still outstanding: Maintenance-dosing studies

What the programme covers

TRIUMPH is not a single trial but a set of registrations testing retatrutide in progressively harder populations. TRIUMPH-1 is the pivotal obesity study. TRIUMPH-2 addresses obesity with type 2 diabetes. TRIUMPH-3 addresses severe obesity with established cardiovascular disease. TRIUMPH-4 reported first, in December 2025. Full identifiers, endpoints and enrolment criteria are on ClinicalTrials.gov.

Readout timeline

The programme reported in sequence across roughly eight months. TRIUMPH-4 came first in December 2025. TRIUMPH-1 followed on 21 May 2026 with the headline obesity result. TRIUMPH-2 and TRIUMPH-3 reported together in July 2026, both meeting their primary endpoints in their respective comorbid populations.

TRIUMPH-4: first readout, December 2025
TRIUMPH-1: pivotal obesity, 21 May 2026, 2,339 randomised
TRIUMPH-2: obesity with type 2 diabetes, July 2026
TRIUMPH-3: severe obesity with established CVD, July 2026
Maintenance-dosing studies: further readouts expected

Research material referenced

Retatrutide 10mg, third-party HPLC tested

Buy Retatrutide · £49.99

What TRIUMPH-1 reported

Across 2,339 randomised adults, mean weight reduction at 80 weeks was 19.0% on 4 mg, 25.9% on 9 mg and 28.3% on 12 mg, against 2.2% on placebo. A 104-week extension in 532 participants reported 30.3% mean reduction on 12 mg among those with baseline BMI of 35 or above. Gastrointestinal adverse events were common and discontinuation on the 12 mg arm was 11.3% against 4.9% on placebo.

Why maintenance data are the outstanding question

Several further Phase 3 readouts were expected across 2026, including studies of maintenance dosing (what happens when the dose is reduced or stopped after the reduction phase). Weight regain after discontinuation is the unresolved question across the entire incretin class, not just for retatrutide, and it is what the field is waiting on.

Regulatory position

Positive pivotal results do not confer authorisation. Retatrutide remains investigational in every jurisdiction. Lilly has indicated an intended FDA Biologics License Application in the first quarter of 2027. The dose arms described above are facts about a registered trial run under clinical supervision and are not handling guidance.

Frequently asked questions

Where can I find TRIUMPH trial results?: Trials are registered on ClinicalTrials.gov, with topline results issued by Lilly and peer-reviewed publication following database posting.
Have all the TRIUMPH trials reported?: No. The pivotal trials have reported, but further readouts including maintenance-dosing studies were still expected across 2026.
Does TRIUMPH mean retatrutide is approved?: No. It remains investigational everywhere; an FDA filing was signalled for Q1 2027.

Extended research context

The Retatrutide Research deep dive

Deep dive: how the triple-agonist scaffold was engineered

Retatrutide's 39-residue backbone was designed by Eli Lilly's peptide chemistry team to preserve the pharmacophores of three glucagon-family receptors on a single chain. The N-terminal domain retains GIP-receptor contacts, mid-chain substitutions restore GLP-1-receptor affinity lost in native GIP, and additional residue swaps confer glucagon-receptor engagement. A γGlu-2xOEG linker anchors a C20 fatty diacid at Lys17, which reversibly binds serum albumin and slows renal clearance. This is the same albumin-tethering strategy Novo Nordisk pioneered with semaglutide and Lilly refined further in tirzepatide.

The TRIUMPH Phase 3 programme in context

TRIUMPH is Lilly's global Phase 3 development umbrella for retatrutide, spanning obesity (TRIUMPH-1 through TRIUMPH-4), type 2 diabetes, MASH (metabolic dysfunction-associated steatohepatitis), and knee osteoarthritis linked to obesity. Readouts began in 2025 and continue through 2026. Because the compound is investigational, no regulator (FDA, EMA, or MHRA) has issued marketing authorisation, and legitimate supply exists only for laboratory reference and research contexts, never for human administration.

How retatrutide differs from tirzepatide and semaglutide at the mechanism level

Semaglutide is a mono-agonist (GLP-1 only). Tirzepatide is a dual agonist (GIP + GLP-1). Retatrutide adds glucagon-receptor activity, which pre-clinical and Phase 2 data suggest contributes to energy expenditure in addition to appetite regulation and glucose-dependent insulin release. This three-receptor combination is why retatrutide is sometimes called a 'metabolic multi-tool' peptide in the trade press, but the pharmacology is more nuanced than the label implies.

Research applications

▸In vitro receptor-binding assays across GIP-R, GLP-1R and GCGR panels
▸Comparator studies alongside semaglutide, tirzepatide and liraglutide reference standards
▸Analytical-method development: HPLC retention profiling and LC-MS confirmation
▸Stability testing of lipidated 39-residue peptides in aqueous and lyophilised forms
▸Reference material for teaching incretin pharmacology in university-level courses

Handling checklist

✓Store lyophilised vials at −20 °C; protect from light and humidity
✓Reconstitute with bacteriostatic water; avoid vortexing (foams the peptide)
✓Once reconstituted, store at 2–8 °C and use within 28 days
✓Verify batch CoA: HPLC ≥98%, mass matches ~4,731 Da, endotoxin low
✓Do not administer to humans or animals. Research use only

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Confusing retatrutide with tirzepatide in supplier catalogues

Fix: Cross-check the LY code (LY3437943 = retatrutide; LY3298176 = tirzepatide) and the receptor profile on the CoA.

✗ Using tap or filtered water for reconstitution

Fix: Only use bacteriostatic water for injection (0.9% benzyl alcohol) or sterile water, never lab DI water.

✗ Storing reconstituted solution at room temperature

Fix: Refrigerate at 2–8 °C immediately after reconstitution; discard after 28 days.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

UKP

Written and reviewed by

The UK Peptides Editorial Team · Research library, UK Peptides

The editorial team is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate. Corrections are made in place and the review date updated.

How we write and check this content Report a factual error in this article

Popular across the research hub

One flagship guide from every other research category.

← Back to Forum