Retatrutide phase 3: the numbers, and the fine print
Published October 26, 2026. Results are company reported. This is news, not advice.
Quick take: Eli Lilly reported big average weight loss for investigational retatrutide in an 80 week trial. It is not approved, and the numbers describe a supervised study, not any product sold elsewhere.
The headline
TRIUMPH-1 enrolled 2,339 adults with obesity or overweight and at least one related condition, without diabetes. It was randomized, double blind and placebo controlled. Lilly reports all three doses met the main goals.
| Dose | Average weight loss at 80 weeks |
|---|---|
| 4 mg | 19.0% |
| 9 mg | 25.9% |
| 12 mg | 28.3% |
In a blinded extension of 532 participants with a body mass index of at least 35, the 12 mg group averaged 30.3% at 104 weeks.
The fine print
- Digestive side effects were common and more frequent than on placebo. Nausea ran from 28.6% to 42.4% across doses, against 14.8% on placebo.
- Stopping because of side effects rose with dose: 4.1%, 6.9% and 11.3%, against 4.9% on placebo.
- Company reported. The numbers come from Lilly's announcement, as covered by a medical news outlet.
What to watch next
Further trials were expected to report later in the year, in people with type 2 diabetes and in people with cardiovascular disease. Approval has not been announced in the source I used.
How to judge reports like this: read peptide news without getting fooled.
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Common questions
Is retatrutide approved?
No. It is investigational, per the source I used.
Who ran the trial?
Eli Lilly, and the results are company reported.
Do these results apply to other products?
No. A trial describes the sponsor's product under supervision.
Sources
Summarised in my own words. Read the originals for the full detail.