An experimental Eli Lilly drug, retatrutide, has demonstrated substantial weight loss and improved blood-sugar control in people with type 2 diabetes, signalling a potential breakthrough in metabolic health treatments.
An experimental Eli Lilly obesity drug has helped people with type 2 diabetes lose substantial amounts of weight while also improving blood-sugar control, according to results set to be presented at the European Association for the Study of Diabetes meeting in Milan and published in The Lancet. The findings add to growing evidence that next-generation weight-loss medicines could do more than trim body mass; they may also improve metabolic health in people for whom losing weight has long been especially difficult.
The trial, known as TRIUMPH-2, enrolled more than 2,000 adults across 92 sites in eight countries, all of whom had overweight or obesity and type 2 diabetes. Participants received weekly injections of retatrutide, at doses of 4mg, 9mg or 12mg, or a placebo. After 80 weeks, average weight loss ranged from 11.9% at the lowest dose to 18.8% at the highest, compared with 5.1% for placebo. Nearly half of those on 12mg lost at least 20% of their starting weight, and almost a third lost at least a quarter of it.
Retatrutide is described by Eli Lilly as a triple agonist because it mimics three hormones involved in regulating appetite, blood sugar and metabolism: GLP-1, GIP and glucagon. That sets it apart from existing GLP-1 medicines, which typically act on one or two pathways. The company said the drug’s effects on blood-sugar control were also notable, with about 72% of patients on the highest dose reaching an HbA1c of 6.5% or lower, the standard threshold used in the NHS to diagnose diabetes. The placebo group stood at 29%. Lilly has previously reported similarly strong weight-loss results in obesity studies, including phase two data published in The New England Journal of Medicine.
The safety profile in TRIUMPH-2 was broadly in line with other medicines in this class, with diarrhoea and nausea the most common side effects. Seven deaths occurred during the study, but investigators said none were linked to the treatment. Lilly said the results support the idea that treating obesity directly can improve outcomes in people with type 2 diabetes, though further research is needed to establish whether the benefits extend to wider complications linked with excess weight. The company’s broader retatrutide programme has also attracted attention beyond diabetes, with earlier and related studies suggesting possible benefits for conditions such as obstructive sleep apnoea and knee osteoarthritis pain. At the same diabetes meeting, researchers also reported early results for petrelintide, a separate once-weekly drug based on the hormone amylin, which appeared to produce more than 10% weight loss with relatively few side effects.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
