RESEARCH NOTES · 30 OCTOBER 2026
What the research found
A 2023 randomised phase 2 trial enrolled 338 adults with obesity or overweight and a weight-related condition. At 48 weeks, the highest-dose retatrutide group had an average weight reduction of 24.2%, compared with 2.1% with placebo. These group averages were encouraging, but they are not a prediction of any individual’s outcome. The study was funded by Eli Lilly. Read the peer-reviewed trial.
A newer development
On 28 October 2026, Lilly announced topline results from a separate phase 3 trial in adults with type 2 diabetes. It reported greater reductions in blood glucose and body weight with retatrutide than with the studied semaglutide comparator. This was a manufacturer announcement, not a substitute for independent appraisal of a full peer-reviewed report. It also involved a different population from the earlier obesity trial. Read the announcement.
What remains uncertain
Gastrointestinal adverse events were common in the phase 2 trial, and increases in heart rate were observed. Long-term benefits and risks need continued evaluation. Lilly’s October 2026 information still describes retatrutide as investigational and unapproved by regulators. These findings do not establish the identity, purity or safety of products sold under the same name outside clinical trials. Read the development-status information.
Educational summary, not personal medical advice or an endorsement of a supplier or product. No dosing or ordering guidance is provided. This editorial has not been independently medically reviewed. Sources checked 30 October 2026.