Retatrutide trial data: why 28.3% and 20.8% differ
Two retatrutide trials reported 28.3% and 20.8% average weight loss. The gap tracks who was enrolled, which matters when either figure is quoted.
Two figures are often attached to retatrutide: 28.3% and 20.8%. Both describe average weight loss, and both come from the same molecule. They come from different trials with different populations, and a figure quoted without its population is easy to misread.
Two trials, two populations
The 28.3% figure came from TRIUMPH-1, a trial that excluded adults with diabetes. It is the headline number most often repeated.
The 20.8% figure came from TRIUMPH-2, the trial that enrolled adults with type 2 diabetes. Same peptide, different population, different number.
Why the population matters when reading the numbers
An average is a property of the group that was measured. When two trials enroll different groups, their averages answer different questions. The 7.5 percentage-point gap between the two figures is therefore not a single effect size for the molecule. It reflects the molecule and the population together.
The post does not say why the figures differ, and this article does not speculate. The gap alone shows that one headline number cannot stand in for both trials.
Quoting the figures accurately
A few habits keep a citation faithful to the source:
- State the trial name or the enrolled population next to every percentage.
- Do not average the two figures or read one as a correction of the other.
- Check the original publication for the endpoint definition and the analysis population before reusing either number.
What this does and does not tell us
The two figures show that reported magnitude depended on the enrolled population. They do not show a ranking of populations, and they say nothing beyond the trials themselves. For anyone writing about incretin-receptor research, the practical point is narrow: give each number its context, and cite each trial separately.