The short answer
STEP 2 found greater average weight loss with semaglutide 2.4 mg than placebo in adults with overweight or obesity and type 2 diabetes. The population matters: many familiar weight-loss headlines come from trials excluding diabetes.
What happened?
The trial randomized 1,210 participants across semaglutide 2.4 mg, semaglutide 1.0 mg and placebo groups. All received lifestyle support. The main weight comparison at 68 weeks was −9.6% with 2.4 mg versus −3.4% with placebo.
Percent of starting weight
Original chart based on the study. Values are reported group averages.
| Group or measure | Average result |
|---|---|
| Semaglutide 2.4 mg | −9.6% |
| Placebo | −3.4% |
The trade-off
Digestive adverse events occurred in 63.5% of participants receiving 2.4 mg, versus 34.3% with placebo, mostly mild or moderate. Those are event frequencies, not discontinuation rates.
The result provides evidence in people with type 2 diabetes. Comparing its percentage with a different trial does not prove what caused the difference: populations, treatments and study conditions all matter.
Sources
Davies and colleagues, STEP 2, The Lancet, 2021. Funded by Novo Nordisk. Study abstract · Paper.