Retatrutide TRIUMPH Phase 3 Results

HEADLINETRIUMPH-1 · 80wk

28.3%

AT 104 WEEKSExtension

30.3%

PARTICIPANTS, PH3Four readouts

5,885

REGULATORYPlanned BLA

Q1 2027

The number to lead with is 28.3% average body weight reduction at 80 weeks on 12mg, from TRIUMPH-1, the pivotal obesity trial, in 2,339 participants, against 2.2% on placebo. Everything else on this page sits underneath that sentence. The 2023 Phase 2 figure of 24.2% over 48 weeks remains citable as history and should never be presented as the current result.

Nothing here is a treatment claim. Retatrutide has no approval in any country, no brand name and no FDA Philippines registration. What follows is trial data, reported in the trial populations it came from, and it is not medical advice.

Below is every retatrutide efficacy readout published to date, with the Phase 2 trial included at the top so the gap between the old figure and the current one is visible rather than implied. Percentages are average body weight reduction at the stated week, in the stated population.

A dash means that dose arm was not part of that trial, or was not reported separately. TRIUMPH-2 also reported an A1C reduction of 1.6% at 9mg and 1.5% at 12mg, against 0.2% on placebo. TRIUMPH-4 carried a co-primary knee pain endpoint alongside weight.

Four readouts does not mean four equal readouts. TRIUMPH-1 is the study the rest of the programme is arranged around, for three reasons.

It is the general obesity trial. Its participants were enrolled on obesity alone, without a second condition shaping eligibility. TRIUMPH-4 required knee osteoarthritis, TRIUMPH-2 required type 2 diabetes, TRIUMPH-3 required established cardiovascular disease. Each of those filters changes who ends up in the trial, and therefore what the average result means.

It runs the full dose ladder. TRIUMPH-1 reported 4mg, 9mg and 12mg separately, which is what makes a dose response visible: 19.0%, 25.9% and 28.3%. The step from 4mg to 9mg is roughly seven percentage points. The step from 9mg to 12mg is roughly two and a half. That flattening at the top of the ladder is one of the more informative shapes in the whole dataset, because the adverse event and discontinuation curves keep climbing across the same interval.

It is the largest and the longest. At 2,339 participants over 80 weeks, plus a 104-week extension, it carries more statistical weight than the other three and is the study a regulator reads first.

None of this makes the other trials decoration. TRIUMPH-3 in particular matters for reasons that have little to do with the weight figure, covered in the heart rate filing.

A Phase 3 programme is not four attempts at the same experiment. Each trial was built to answer a question a regulator, a payer or a prescriber will eventually ask, and the population is the answer to that question.

TRIUMPH-4, knee osteoarthritis. This trial asked whether weight reduction in people carrying a mechanical joint burden translates into measured pain relief, and it carried a WOMAC pain endpoint alongside weight. It read out first, in December 2025, which is why its 28.7% spent months as the most quoted Phase 3 number before TRIUMPH-1 existed. It is also the smallest of the four at 445 participants, and 84% of them had a baseline BMI of 35 or above.

TRIUMPH-2, type 2 diabetes. This asked what the compound does when glucose control is already impaired. Weight reduction came in lower, at 20.8% on 12mg, alongside an A1C reduction of 1.6% at 9mg. Lower weight loss in diabetes populations is the normal pattern across the entire incretin class and is not evidence of a weaker drug. It is evidence that the two populations are not the same population.

TRIUMPH-3, severe obesity with cardiovascular disease. The largest of the three 2026 readouts at 1,949 participants, and the one closest to the people who carry the most risk. It reported 22.6% on 12mg. Its real value is safety exposure in a cardiovascular population, which is the bridge to TRIUMPH-OUTCOMES.

TRIUMPH-1, obesity. The clean question. What happens across a full dose ladder in adults with obesity and no mandated second condition, over 80 weeks.

This is worth stating flatly because the error is everywhere, including on pages that otherwise look careful. The 2023 Phase 2 trial, published in the New England Journal of Medicine by Jastreboff and colleagues, enrolled 338 adults with obesity, ran 48 weeks, and reported 24.2% average body weight reduction at 12mg against 2.1% on placebo. That is the whole of the Phase 2 obesity result.

The figure 28.7% belongs to TRIUMPH-4: Phase 3, 68 weeks, 445 participants, knee osteoarthritis population, read out in December 2025. The figure 28.3% belongs to TRIUMPH-1: Phase 3, 80 weeks, 2,339 participants, read out in May 2026. Writing "28.7% over 48 weeks" or attaching either Phase 3 number to the NEJM citation is a conflation of two separate studies, and it is the specific error that propagated across most of the English-language coverage of this compound.

The class comparisons deserve the same discipline. Tirzepatide reported 22.5% in SURMOUNT-1 at 72 weeks. Semaglutide reported 14.9% in STEP 1 at 68 weeks. Retatrutide reported 28.3% in TRIUMPH-1 at 80 weeks. Three different durations, three different trial designs, no head-to-head randomisation between any of them. The ordering is probably directionally right and the margins are not measured quantities. TRIUMPH-5 is the trial that will actually test retatrutide against tirzepatide in the same protocol, and until it reports, the honest phrasing is "larger in separate trials of different length". There is more on the indirect comparison in the retatrutide versus tirzepatide filing and the semaglutide comparison.

Alongside the 80-week TRIUMPH-1 result, Lilly reported a 104-week figure from an extension of 532 participants with a baseline BMI of 35 or above who continued on treatment. Average reduction in that group reached 30.3%, equivalent to 85.0 lbs.

The useful reading is about shape rather than size. Most weight loss trials show a curve that flattens somewhere between weeks 40 and 72, and the interesting question is whether the plateau is a true ceiling or an artefact of the trial stopping. A figure that is still moving upward between week 80 and week 104 suggests the 80-week number was not yet a plateau in that subgroup.

The limits matter as much as the signal. This was an extension of participants who continued, not a fresh randomisation, so people who stopped for tolerability or any other reason are not in it. It was restricted to a higher-BMI subgroup. At 532 participants it is under a quarter of the parent trial. None of that makes 30.3% wrong. It makes it a durability observation in a selected group rather than a second pivotal result, and it says nothing about what happens after discontinuation. That question belongs to TRIUMPH-6.

Efficacy is the headline and tolerability is the story. Across TRIUMPH-1, the gastrointestinal cluster ran at nausea 28.6% to 42.4%, diarrhoea 25.2% to 34.1% and constipation 23.8% to 26.1% across the three dose arms. Discontinuation for adverse events ran 4.1% at 4mg, 6.9% at 9mg and 11.3% at 12mg, against 4.9% on placebo.

That discontinuation ladder is the number that changes how the efficacy table should be read. Moving from 9mg to 12mg buys roughly two and a half percentage points of additional weight reduction and roughly doubles the rate at which people leave the trial because of side effects.

The Phase 3 programme also surfaced an adverse event that Phase 2 did not distinguish: dysesthesia, an altered or unpleasant skin sensation. TRIUMPH-4 reported it in 8.8% at 9mg and 20.9% at 12mg against 0.7% on placebo, and Lilly described the events as generally mild and rarely leading to discontinuation. Because it appears only in Phase 3, pages built on Phase 2 data omit it entirely. Full figures across all four readouts sit in the consolidated side effect filing and the dedicated dysesthesia filing.

Three Phase 3 trials have not reported, and each answers a question the four published readouts cannot.

On the regulatory side, Lilly stated on 23 July 2026 that it plans to submit a Biologics License Application for retatrutide to the US FDA in Q1 2027. That is a plan to file, not an approval, and a filing opens a review period rather than closing one. Nothing in the four published readouts changes the fact that retatrutide is currently unapproved everywhere.

None of the above creates a Philippine registration. Retatrutide does not appear in the FDA Philippines verification portal, because it is not registered there, and it will not appear on the basis of a US filing. Any Philippine access is research access, and the compound is supplied and handled as research material. The general country picture sits in the retatrutide Philippines filing, and the regulatory background in the FDA Philippines guide.

Two practical points follow from the trial data for anyone handling the compound in this country. Storage discipline in a tropical climate is a real variable, and it is covered in the heat and storage filing. And the dose ladder in the trials was slow and stepped, which is why the reconstitution calculator works in trial units rather than in recommendations.

1. [01]TrialLilly · TRIUMPH-1 pivotal readout, 21 May 2026

   Dose-by-dose weight reduction at 80 weeks, the 104-week extension, adverse event and discontinuation rates.

   investor.lilly.com · TRIUMPH-1 release
2. [02]TrialLilly · TRIUMPH-2 and TRIUMPH-3 readout, 23 July 2026

   Weight and A1C results in type 2 diabetes and in severe obesity with cardiovascular disease, plus the Q1 2027 BLA statement.

   investor.lilly.com · TRIUMPH-2 and TRIUMPH-3 release
3. [03]TrialLilly · TRIUMPH-4 readout, 11 December 2025

   First Phase 3 readout, obesity with knee osteoarthritis, 68 weeks, including the dysesthesia figures.

   investor.lilly.com · TRIUMPH-4 release
4. [04]TrialNEJM 2023 · Retatrutide Phase 2 obesity trial

   Jastreboff AM et al. Triple-hormone-receptor agonist retatrutide for obesity, a Phase 2 trial. N Engl J Med 2023;389:514-526.

   https://www.nejm.org/doi/full/10.1056/NEJMoa2301972
5. [05]RegistryClinicalTrials.gov · TRIUMPH-OUTCOMES, NCT06383390

   Cardiovascular and renal outcomes trial, approximately five years, currently recruiting.

   https://clinicaltrials.gov/study/NCT06383390