Weight-loss trials
8 trials · 15,462 people
Everyone asks the same question: how much weight do you lose? The trials answer it, and the answer is not the one in the advertising. People in the placebo group lose weight too — so the drug's real effect is the difference between the two bars, not the height of one.
8 trials
Results published in a journal come first; a press-release figure never outranks them. Largest weight loss first within each.
- Treatment-8.7% to -24.2%placebo-2.1%
- Treatment-15% to -20.9%placebo-3.1%
The range is three separate dose arms, not an uncertainty interval.
Source — SURMOUNT-1, NEJM 2022 - Treatment-20.4%placebo-3%
This result is cagrilintide COMBINED with semaglutide. The monotherapy arm (302 participants) has no reported result.
Source — REDEFINE 1, NEJM 2025 - Treatment-20.2%semaglutide-13.7%
The comparator is semaglutide, not placebo — hence the small gap.
Source — SURMOUNT-5, NEJM 2025 - Treatment-14.9%placebo-2.4%
In the trial's journal paper, 50.5% reached at least 15% weight loss, against 4.9% on placebo.
Source — STEP 1, NEJM 2021 - Treatment-6.2% to -14.9%placebo-2.8%
Only 233 of 386 participants (60.4%) completed the treatment period.
Source — Phase 2, Lancet D&E 2024 - Treatment-8.4 kgplacebo-2.8 kg
Reported in kilograms rather than as a share of body weight, so it cannot be set directly against the percentage figures.
Source — SCALE, NEJM 2015 - Treatment-19% to -28.3%placebo-2.2%
Topline figures from a press release. Not published in a peer-reviewed journal, and therefore not the same kind of evidence as the published trials here.
Source — TRIUMPH-1, Eli Lilly 2026