Retatrutide Results Timeline in Trials

PH2 · 24 WEEKS12mg group

17.5%

PH2 · 48 WEEKS12mg group

24.2%

TRIUMPH-1 · 80 WK12mg arm

28.3%

EXTENSION · 104 WKContinuers

30.3%

Those four figures are the published timeline. They come from two different trials and that distinction is not decorative, so it is carried through every table on this page. The two Phase 2 points describe the same participants at two moments. The two Phase 3 points describe a much larger and longer trial and a subgroup extension of it.

What the sequence shows is a curve that rises steeply, decelerates steadily, and was still rising at the last published measurement. Nothing here is a treatment claim or a prediction. Retatrutide has no approval in any country, no brand name and no FDA Philippines registration, and none of this is medical advice.

A weight loss trial curve is a line through the average of a large group at each scheduled visit. Three things follow from that sentence, and all three get lost in the way these curves are usually presented.

It is an average, so nobody is on it. Every participant has their own trajectory. The curve is the centre of a cloud, and in obesity pharmacology that cloud is wide. Reading a point off the curve and calling it what happens at month nine describes a statistical construct rather than a person.

It is smoothed by scheduling. Points exist where the protocol put a visit. Between them the line is drawn, not measured. Real individual weight moves week to week in a way no trial curve shows.

It carries an estimand. The TRIUMPH-1 efficacy figures represent efficacy had all randomised participants remained on study intervention without initiating other weight management treatments. Lilly reported a separate treatment-regimen estimand representing the average effect regardless of adherence. Those answer different questions, and the headline number is the first kind. It is a well-defined and standard way to report a trial. It is not a description of what happened to everyone who started.

The table below is the complete published timeline for the 12mg dose. There are no week-four or week-twelve figures because no readout published them. Where a figure is absent from this table, it is absent from the record.

The 24-week and 48-week rows are the primary and a secondary endpoint of the same Phase 2 trial, so those two points do describe one group over time. The remaining rows are separate studies in differently selected populations. Reading all five as one continuous curve is a mistake, and it is one that a lot of published timeline content makes.

The other TRIUMPH readouts sit at 80 weeks as well: TRIUMPH-2 reported 20.8% in type 2 diabetes alongside an A1C reduction of 1.6%, and TRIUMPH-3 reported 22.6% in severe obesity with established cardiovascular disease. The full readout by readout table with every dose arm is in the TRIUMPH results filing.

This is the part of the timeline that generates the most search traffic and the least reliable content, and the reason is structural: for the first few months, the trials were not measuring the dose they were named after.

In TRIUMPH-1, every active arm started at 2mg once weekly and escalated stepwise every four weeks. The 4mg arm reached maintenance after a single step. The 9mg arm stepped through 2mg, 4mg and 6mg. The 12mg arm stepped through 2mg, 4mg, 6mg and 9mg, which on that cadence puts it at maintenance from around week sixteen.

Layer the pharmacokinetics on top. The published half-life is approximately six days, which puts time to steady state at roughly four weeks. So even once a maintenance dose is reached, exposure keeps climbing for about another month before it settles. The practical consequence is that the 12mg arm was not at steady exposure at its assigned dose until somewhere around week twenty of an 80-week trial.

That is why an early figure, if one existed, would not mean what it appears to mean. It would describe a moving exposure, not a dose. It is also why comparing an early number across arms would compare arms that are at different points in their own escalation. The escalation detail is set out in the titration filing and the exposure arithmetic in the half life filing.

The most informative way to read the published points is as rates rather than levels, because the rate is where the shape lives.

Within the Phase 2 trial, and this is the one comparison that stays inside a single study, the 12mg group moved from baseline to 17.5% across the first 24 weeks, then from 17.5% to 24.2% across the next 24. Roughly 17.5 percentage points in the first half of the year, roughly 6.7 in the second. The rate across the second interval is approximately a third of the first.

That deceleration is the normal shape for this class and is not a sign of anything going wrong. Part of it is the titration period being loaded into the first interval. Part of it is that a smaller body loses less weight for the same relative effect. And part of it is the adaptive fall in energy expenditure that accompanies weight loss, which is the mechanism the glucagon receptor component of this compound is hypothesised to push against, discussed in the glucagon receptor filing.

What the deceleration is not, on the published record, is a stop. Every published interval is positive, including the last one.

TRIUMPH-1 is the pivotal readout, and 80 weeks is its primary duration: 2,339 adults with obesity randomised 1:1:1:1 to 4mg, 9mg, 12mg or placebo.

Lilly additionally reported that 65.3% of the 12mg arm reached a BMI below 30. Discontinuation for adverse events across the arms ran 4.1% at 4mg, 6.9% at 9mg and 11.3% at 12mg, against 4.9% on placebo.

Eighty weeks is roughly eighteen months, and that duration is itself part of the timeline story. A compound evaluated over eighteen months is being asked a different question from one evaluated over six, and the answer at eighteen months is the one a regulator reads.

Alongside the 80-week result, Lilly reported a 104-week figure from an extension of 532 participants who had a baseline BMI of 35 or above and who completed the main 80-week study. Average reduction in that group reached 30.3%.

The value of that number is not its size. It is what it says about the shape of the curve at the point where the parent trial stopped. Weight loss trials in this class generally show a plateau, and the plateau is usually visible well before week 80. A figure that is still moving upward between week 80 and week 104 means the 80-week number was not a ceiling in that subgroup. The curve had not finished.

That is a genuinely uncommon thing to be able to say about a weight loss trial, and it is the single strongest piece of evidence any timeline discussion of this compound has access to.

This is the section that most pages competing for these searches do not write, and it is the one that makes the rest of the page usable.

The 12mg arm of TRIUMPH-1 reported an average of 28.3%. In the same arm, 45.3% of participants reached at least 30% reduction. Those two facts together tell you the distribution is wide: nearly half the arm cleared a threshold above the mean, which means a substantial share of the arm landed well below it. A mean of 28.3% is consistent with a great many individual trajectories, including flat ones.

Then there are the people who are not in the efficacy figure in the way a casual reader assumes. Across the 12mg arm, 11.3% discontinued because of adverse events. The headline efficacy figure is an estimand representing the result had all randomised participants remained on study intervention. It is a standard and honest way to report a trial, and it is not the same as the average outcome among everyone who started.

Finally, and most obviously, none of the conditions that produced these figures are reproducible outside a trial. Participants were screened, supervised, monitored, given an investigational product of known composition, and supported through escalation with the option to hold or stop. Retatrutide is approved nowhere. There is no product, no label, and no clinical framework for an individual outside a trial to be inside.

One last reason a timeline is not portable: the population changes the answer, at identical dose and identical duration.

At 80 weeks on 12mg, TRIUMPH-1 in general obesity reported 28.3%. TRIUMPH-3, in severe obesity with established cardiovascular disease, reported 22.6% at the same dose over the same duration in 1,949 participants. TRIUMPH-2, in adults with type 2 diabetes and obesity or overweight, reported 20.8% in 1,152 participants, alongside an A1C reduction of 1.6%. TRIUMPH-4 ran a shorter 68 weeks in an obesity plus knee osteoarthritis population of 445 and reported 28.7%.

Lower weight reduction in a diabetes population is the expected pattern across the whole incretin class rather than a sign of a weaker result. Ranking those four numbers against each other measures the populations, not the compound. The only clean comparisons in the dataset are between dose arms inside a single trial.

On regulatory status, Lilly stated on 23 July 2026 that it plans to submit a Biologics License Application to the US FDA in Q1 2027. That is a plan to file. It creates no approval and no Philippine registration. The country picture is in the retatrutide Philippines filing, the regulatory background in the FDA Philippines guide, and the trial curves themselves are modelled in the projection tool, which works in trial figures rather than personal predictions.

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

   The 80-week figures by arm, the responder proportions, the 104-week extension in 532 participants, the discontinuation rates, and the estimand definitions quoted in section 02.

   investor.lilly.com · TRIUMPH-1 release
2. [02]TrialLilly · Phase 2 results published in NEJM, June 2023

   Source of the two within-trial time points used in sections 03 and 05: 17.5% at the 24-week primary endpoint and 24.2% at 48 weeks.

   investor.lilly.com · Phase 2 release
3. [03]TrialLilly · TRIUMPH-2 and TRIUMPH-3 readout, 23 July 2026

   The 80-week results in type 2 diabetes and in severe obesity with cardiovascular disease used in section 09, plus the Q1 2027 BLA statement.

   investor.lilly.com · TRIUMPH-2 and TRIUMPH-3 release
4. [04]TrialLilly · TRIUMPH-4 readout, 11 December 2025

   The 68-week readout in obesity with knee osteoarthritis, the only Phase 3 time point that is not at 80 weeks.

   investor.lilly.com · TRIUMPH-4 release
5. [05]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