The short answer
An analysis of the STEP trials found substantial weight loss even among participants who did not report digestive side effects.
What was examined?
Researchers pooled STEP 1–3 data from 2,117 people assigned semaglutide 2.4 mg and 1,262 assigned placebo. They examined digestive symptoms and their relationship with weight change over 68 weeks.
Nausea affected 43.9% with semaglutide versus 16.1% with placebo. Diarrhea, vomiting and constipation were also more common with semaglutide. Digestive symptoms led 4.3% of semaglutide participants to permanently stop treatment.
Percent of participants
Original chart based on the study. Values are reported group results.
| Group or measure | Result |
|---|---|
| Semaglutide | 43.9% |
| Placebo | 16.1% |
What did the analysis suggest?
A statistical model estimated that digestive side effects explained less than one percentage point of semaglutide’s additional weight loss versus placebo. Most of the weight-loss difference was unrelated to those symptoms in the model.
The useful takeaway
Feeling nauseated is not a reliable sign that a medicine is working. This exploratory analysis supports separating weight outcomes from side-effect severity.
The model relied on assumptions, and some comparisons excluded people who stopped treatment. It does not predict an individual’s experience.
Sources
Wharton and colleagues, Diabetes, Obesity and Metabolism, 2022. Funded by Novo Nordisk. Read the paper.