Lilly’s Retatrutide Yields Up to 28% Weight Loss, 70-Pound Drop
Retatrutide, Lilly’s triple hormone agonist, achieved 19%–28% weight loss in a late-stage trial, with 12 mg subjects shedding an average 70 pounds and nearly half exceeding 30% loss over 80 weeks. Lilly plans an FDA submission this year, positioning retatrutide to directly challenge existing therapies including Novo Nordisk’s Wegovy and Zepbound.
1. Trial Results
In the late-stage study, participants on retatrutide achieved average weight losses of 47 pounds (19%) at 4 mg, 64 pounds (26%) at 9 mg and 70 pounds (28%) at 12 mg doses over 80 weeks. Nearly two-thirds of those on the highest dose fell below obesity thresholds, and almost half lost over 30% of their body weight, rivaling surgical outcomes.
2. Mechanism and Comparison
Retatrutide activates GIP, GLP-1 and glucagon receptors simultaneously, distinct from current GLP-1–only drugs. This multi-hormone approach underpins its superior efficacy versus existing injectable and oral obesity treatments.
3. Regulatory and Market Outlook
Lilly intends to file for FDA approval this year, aiming to expand its obesity portfolio beyond Zepbound and Foundayo. Upon approval, retatrutide will compete directly with Novo Nordisk’s Wegovy, potentially reshaping market dynamics in the growing weight-loss drug segment.