What did ATTAIN-1 study?
ATTAIN-1 was a randomized, placebo-controlled phase 3 study of orforglipron in adults with obesity without diabetes. Participants were followed for 72 weeks. The trial found greater average weight reduction with orforglipron than with placebo.
In the published treatment-regimen analysis, average weight change was −11.2% in the highest studied dose group and −2.1% with placebo. Gastrointestinal events were the most common adverse events and were generally mild to moderate. Some participants stopped treatment because of adverse events.
Source: Wharton et al., ATTAIN-1, New England Journal of Medicine (2025) ↗
Read more than the headline.
A percentage is easier to understand when you know the study population, duration, comparator and method used to account for treatment discontinuation. Different analyses can report different estimates. Keep those details attached when discussing a study with your clinician.
Three useful questions
- Who was studied? Check whether the participants resemble the people the claim is being applied to.
- What was compared? A placebo comparison does not establish superiority to every other treatment.
- Which product was tested? An ingredient name alone is not evidence that every brand has the same performance.
Evidence should support a conversation.
Bring the original paper to your appointment if a claim matters to your decision. Ask what the result means for your circumstances, what remains uncertain, and what would lead your clinician to reconsider the plan.