What has changed?
New retatrutide findings appeared in autumn 2026. Some involved people without diabetes and others people with type 2 diabetes. Not all the numbers can therefore be directly compared. [7] [8]
The key question is whether retatrutide helps people and which side effects it causes. A record number of kilograms lost does not provide a complete answer.
How much weight did participants lose?
Two studies compared retatrutide with a preparation without the active study ingredient, called placebo. Both lasted 80 weeks, about a year and a half. In each trial, people taking retatrutide lost more weight. [7] [8]
In the study of people with type 2 diabetes, the highest studied dose produced average weight loss of about 19%. These are group averages, not every person's result. [8]
What do these percentages mean in kilograms? See a simple example.
New comparison with Ozempic
On 28 October, Lilly reported results comparing retatrutide with Ozempic. The participants had type 2 diabetes. At the highest retatrutide dose studied, average weight loss was about 21%, compared with about 9% with Ozempic. [9]
However, more people taking retatrutide stopped treatment because of side effects: about 8 in 100. With Ozempic, this was about 3 in 100. [9]
These figures were calculated differently from the results described above. We therefore do not put them into a simple ranking.
What do we still not know?
We do not know how retatrutide will work for a particular person or what problems may arise after many years. Results from the ongoing trial comparing it with tirzepatide are not yet available either. [12]
An important limitation of this article: for two studies, we had access to summaries written by the authors. We did not read the full articles. Information about the new comparison with Ozempic comes from the manufacturer.
The company developing retatrutide funded the studies discussed. This matters when assessing its announcements. [7] [8] [9]
What does this mean for someone who wants to lose weight?
The findings justify further research. They do not promise a specific weight loss or encourage buying retatrutide online. It is not yet an approved medicine. [10]
Start with plain-language profile of retatrutide and its possible side effects. If you are looking for treatment for yourself, discuss the available options with your doctor.
Exact figures — for interested readers
Show study names, numbers and how they were calculated
The table shows results for the highest studied dose: retatrutide 12 mg. This describes a trial, not instructions for use.
| Study and participants | Retatrutide |
|---|---|
| TRIUMPH-1: 2,339 people without diabetes [7] | −25,0% |
| TRIUMPH-2: 1,152 people with type 2 diabetes [8] | −18,8% |
| TRANSCEND-T2D-2: 1,298 people with type 2 diabetes [9] | −20,9% |
First two rows: the treatment-regimen analysis also included treatment discontinuations. Third row: the efficacy estimand estimates the result assuming continued treatment without additional glucose-lowering medicines. These are different calculation methods. [7] [8] [9]
In TRANSCEND-T2D-2, mean weight change with Ozempic 2 mg was −9.4%. Side effects led 7.9% of retatrutide 12 mg recipients and 2.7% of Ozempic 2 mg recipients to stop treatment. These values were rounded in the text. [9]
Sources for the first two studies: abstracts, or the authors' summaries. The third source is Lilly's announcement of 28.10.2026. The Ozempic comparison does not cover every way semaglutide is used.
Where does this information come from?
Show sources and how they were checked
- Jastreboff i wsp.: TRIUMPH-1, NEJM
Phase 3 trial publication · online 29 September 2026 · PubMed abstract reviewed · DOI: 10.1056/NEJMoa2604169. Accessed: 2 November 2026.
- Bellido i wsp.: TRIUMPH-2, The Lancet
Phase III study publication · online 29.09.2026, issue 10.10.2026 · PubMed abstract read · DOI: 10.1016/S0140-6736(26)01861-1. Accessed: 02.11.2026.
- Lilly: wyniki TRANSCEND-T2D-2
Sponsor announcement · 28 October 2026 · full page; preliminary results, not a peer-reviewed article. Accessed: 2 November 2026.
- ClinicalTrials.gov: TRIUMPH-5 (NCT06662383)
Trial registry · API accessed 2 November 2026 · record updated 20 July 2026. Accessed: 2 November 2026.
- FDA: Concerns with Unapproved GLP-1 Drugs
US regulator announcement · full page. Accessed: 02.11.2026.