Retatrutide Results: What the Trials Found
Last updated 13 June 2026
Quick answer
The headline numbers
| Trial | When | Top weight result |
|---|---|---|
| Phase 2 (NEJM) | 2023 | Up to 17.5% in 24 weeks |
| TRIUMPH-4 (Phase 3) | Dec 2025 | Up to ~71 lb average |
| TRIUMPH-1 (Phase 3) | 2026 | Large weight loss + health gains |
| TRANSCEND-T2D-1 | 2026 | Lower A1C and weight in type 2 diabetes |
Why the numbers grew over time
Phase 2 was a shorter study with a 17.5% top result. Phase 3 trials ran longer and used higher doses, so the weight loss numbers were bigger. Longer time plus a higher dose lined up with more change in the data.
A fair word of caution
These results come from controlled trials with set rules and medical care. They show what the peptide can do in research. They are not a guide for taking anything, and your result is not promised. Read the reported side effects too, so you see the full picture.
These numbers are why interest is high if you want to buy retatrutide UK, but remember it is sold for research use only.
Looking at suppliers?
What a trustworthy UK supplier looks likeCommon questions
How much weight did people lose on retatrutide?+
In the Phase 2 trial, adults lost up to 17.5% of their body weight in 24 weeks. In the Phase 3 TRIUMPH-4 trial, the highest dose group lost up to an average of about 71 lb. Results depend on the dose and how long the study ran.
How fast does retatrutide work?+
In trials, weight came off steadily over weeks and months, not days. The biggest changes were seen at the higher doses over longer study periods.