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Retatrutide's phase 3 trials, broken down: TRIUMPH and TRANSCEND

Fourteen phase 3 trials, two programmes, one published so far. Who each retatrutide trial enrols, what it's compared against, and what "completed" really means.

29 September 2026 · 5 min read · Biovanta

In short
  • ClinicalTrials.gov lists 14 phase 3 trials of retatrutide: 10 in the TRIUMPH programme, 3 in TRANSCEND, and 1 outside both.
  • TRIUMPH covers obesity, with trials in specific groups such as people with knee osteoarthritis, sleep apnoea or heart disease. TRANSCEND covers type 2 diabetes.
  • Five are completed, nine still running. Completed is not the same as published: at the time of writing only one phase 3 trial has results in a peer-reviewed journal.
  • The biggest, TRIUMPH-Outcomes, plans to enrol 10,000 people and runs to 2029. It is the one regulators tend to wait for.

Every few weeks a post goes round saying "retatrutide phase 3 results are in". It makes it sound like there's one big trial with one answer. There isn't. The public trial registry lists fourteen phase 3 trials of retatrutide, each asking a different question in a different group of people.

This page walks through them in plain English: who's in each trial, what it's compared against, and where it's up to. It's the design, not the results. If you want to know how to judge any of these yourself, how to read a peptide study is the five-minute version.

Two programmes, fourteen trials

Big drug programmes run as families of trials, each with a shared name and a number:

  • TRIUMPH is the obesity programme: 10 trials.
  • TRANSCEND is the type 2 diabetes programme: 3 trials.
  • SYNERGY-Outcomes sits outside both: a liver-disease trial testing several drugs under one protocol.

Why so many? Because a regulator doesn't just ask "does it do something?". It asks "in whom, compared with what, for how long, and is it safe in people who also have X?". Each trial answers one slice of that.

The TRIUMPH trials (obesity)

TrialWho's in itCompared withBlindingSizeStatus
TRIUMPH-1Adults with obesity or overweight, with sub-groups who have knee osteoarthritis or sleep apnoeaPlaceboDouble-blind2,335Completed
TRIUMPH-2Adults with type 2 diabetes and obesity or overweightPlaceboDouble-blind1,152Completed
TRIUMPH-3Adults with obesity and heart and blood vessel diseasePlaceboDouble-blind1,946Completed
TRIUMPH-4Adults with obesity or overweight and knee osteoarthritisPlaceboDouble-blind445Completed
TRIUMPH-5Adults with obesityTirzepatideDouble-blind~800Running
TRIUMPH-6Adults with obesity, looking at maintenance over timePlaceboDouble-blind~643Running
TRIUMPH-7Adults with obesity or overweight and chronic low back painPlaceboDouble-blind~586Running
TRIUMPH-8Adults with obesity or overweightPlaceboDouble-blind~250Running
TRIUMPH-9Adults with obesity or overweight, without type 2 diabetesThree retatrutide groups compared with each otherDouble-blind~600Running
TRIUMPH-OutcomesAdults with obesity and heart or kidney diseasePlaceboDouble-blind~10,000Running to 2029

A "~" means the size is the registry's planned enrolment rather than the final count.

Three of these are worth a second look:

  • TRIUMPH-5 is head-to-head. It compares retatrutide against tirzepatide, an already-licensed drug, rather than against a dummy. That's a harder test and a more useful one, and it's still running. So any post claiming "retatrutide beats tirzepatide in phase 3" before it reports is ahead of the evidence. Tirzepatide vs retatrutide covers how the two molecules differ.
  • The condition-specific trials (knee osteoarthritis, sleep apnoea, back pain) have their own primary endpoints for that condition, such as a pain score. They're asking a different question from the headline trials.
  • TRIUMPH-Outcomes is the big one. An "outcomes" trial counts serious events, such as heart attacks, strokes and kidney events, over years, in thousands of people. It's slow and expensive, and it's often the trial regulators most want to see.

The TRANSCEND trials (type 2 diabetes)

TrialWho's in itCompared withBlindingSizeStatus
TRANSCEND-T2D-1Adults with type 2 diabetes on diet and exercise alonePlaceboDouble-blind537Completed and published
TRANSCEND-T2D-2Adults with type 2 diabetes on metformin, with or without one other tabletSemaglutideOpen-label~1,250Running
TRANSCEND-T2D-3Adults with type 2 diabetes and moderate or severe kidney impairment, on basal insulinPlaceboDouble-blind~320Running

All three measure a blood marker, HbA1c, as their primary endpoint. Notice TRANSCEND-T2D-2 is open-label: everyone knows which drug they're on. That's common when two treatments look or are given differently, but it's a weaker design than double-blind, and worth remembering when its results appear.

"Completed" is not "published"

This is the part the posts skip. Five of the fourteen trials are marked completed. At the time of writing, one has results in a peer-reviewed journal: TRANSCEND-T2D-1, published in The Lancet in 2026.

Everything else you might have read about the other completed trials comes from press releases or conference presentations. Those are real, but they're not the same thing. A journal paper has been through peer review, gives the full methods and the full set of results, including the ones that didn't go well. A press release is written by the company that ran the trial.

"Completed" in a registry also usually means the primary completion date has passed: the last participant has been measured for the main question. Analysis, writing and peer review come after that, often many months later.

So when you see "phase 3 results", three quick questions:

  1. Which trial? There are fourteen. Ask for the name or NCT number.
  2. Published where? A journal with a DOI, or a press release?
  3. Compared with what? Placebo and tirzepatide are very different comparisons.

Where this leaves retatrutide

It is investigational, with a large phase 3 programme part-way through and one peer-reviewed phase 3 paper so far. It holds no licence anywhere. Its earlier phase 2 trials are broken down in how to read a peptide study, and the molecule itself in retatrutide, explained. How it sits next to semaglutide and tirzepatide is in semaglutide vs tirzepatide vs retatrutide.

Biovanta supplies Retatrutide 40 mg strictly for in-vitro laboratory research, with an independent report per batch.

Sources

  1. ClinicalTrials.gov — retatrutide studies (search)
  2. ClinicalTrials.gov — NCT05929066 (TRIUMPH-1)
  3. ClinicalTrials.gov — NCT06662383 (TRIUMPH-5)
  4. ClinicalTrials.gov — NCT06383390 (TRIUMPH-Outcomes)
  5. ClinicalTrials.gov — NCT06354660 (TRANSCEND-T2D-1)
  6. ClinicalTrials.gov — NCT06260722 (TRANSCEND-T2D-2)
  7. Bajaj HS, et al. (2026). TRANSCEND-T2D-1: a double-blind, randomised, phase 3 trial. The Lancet 407(10546), 2402–2413.
  8. TRIUMPH programme rationale and design. Diabetes, Obesity and Metabolism (2026).

Questions this article answers

How many phase 3 trials of retatrutide are there?

ClinicalTrials.gov lists 14: ten in the TRIUMPH obesity programme, three in the TRANSCEND type 2 diabetes programme, and one liver-disease trial (SYNERGY-Outcomes) outside both. Five are marked completed and nine are still running.

What is the TRIUMPH trial?

TRIUMPH is the name of retatrutide's phase 3 obesity programme, a series of ten numbered trials. Most compare retatrutide with placebo in adults with obesity or overweight, some in specific groups such as people with knee osteoarthritis, sleep apnoea, back pain or heart disease. TRIUMPH-5 compares it with tirzepatide.

What is the TRANSCEND trial?

TRANSCEND is retatrutide's phase 3 programme in type 2 diabetes: three trials, each with the blood marker HbA1c as the primary endpoint. TRANSCEND-T2D-1 compared it with placebo and was published in The Lancet in 2026; TRANSCEND-T2D-2 compares it with semaglutide, open-label.

Have retatrutide's phase 3 results been published?

One has, at the time of writing: TRANSCEND-T2D-1, in The Lancet in 2026. Other trials are marked completed on the registry, but completed means the main measurements are done, not that a peer-reviewed paper exists.

Is retatrutide approved?

No. It is investigational, part-way through its phase 3 programme, and licensed nowhere.

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