| Trial results
Eli Lilly's once-weekly retatrutide was compared with placebo for 80 weeks in 2,339 adults with obesity and no diabetes (TRIUMPH-1). Average weight change was -17.6% at 4 mg, -23.7% at 9 mg and -25.0% at 12 mg, versus -3.9% on placebo.
In the 574 people with knee osteoarthritis, pain scores improved by about 1.6 to 1.8 points more than placebo in the trial's main analysis, on a 1 to 10 scale where higher means worse pain. In the 243 people with obstructive sleep apnea, apnea events per hour fell by about 22 to 25 more than placebo. The most common side effects were stomach and gut problems.
Worth knowing: Lilly paid for the trial. The Atlas read the journal abstract, not the full paper. Retatrutide is not approved for any use, and Lilly has said it plans to file with the FDA in the first quarter of 2027.
Related: Sleep apnea and weight-loss medicines: what the trials show | Trial results explorer | Medicine library
Source: Jastreboff AM, et al. N Engl J Med. Published September 29, 2026 Journal article. ClinicalTrials.gov identifier NCT05929066 Trial registry.